Another excellent video. Other luthiers tell you to use casein but you give us the recipe, application materials, drying methods etc. etc. Many thanks.
From the comments on this video, I understood that after applying the casein, apply mastic. In this regard, I would like to ask you two questions: how is the mastic solution that you apply prepared? After this mastic solution, do you apply anything else before linoxyn varnish?
The Mastic solution is basically a refractive ground, and is prepared simply by dissolving the resin in turpentine essence, with a concentration of 16% by weight (16% mastic - 84% turpentine). I also add some pumice to act as a pore filler, but this can be omitted. It is applied with a brush and immediately afterwards the excess is removed with a rag soaked in alcohol, so that it does not form a glossy surface layer but remains only inside the surface. At least 12 hours in the UV lamp will be needed to let it dry (even 24 hours, depending on the type and power of the lamps), otherwise it is better to wait up to a week without a UV lamp. Once perfectly dry, you are ready to apply the varnish.
Thank you Dear Davide, for sharing your beautiful and inspiring work. Please allow me to learn from your analytical answer? What's the difference in having a dead body "caseinate" (dead, because it doesn't have adequate mechanics to emit vibrations but it changes the wood with its weight in a significant way, in addition to behaving like a stiffening plastic seal, brake and amplitude brake. This seems with a wave compressor. Why not use, for example, a rigid varnish over the instrument? I notice that both modified the stiffness of the part, like a brake/compressor of amplitude and waves? Principle of observation and consideration for this question: Oil Varnish Vs. Indian lacquer varnish + resins. Thinking that the choice of oil varnish is common for having preferable elastic and aesthetic characteristics for acoustic equalization? So what's the use of using a sealant that promotes “brake, brake” and low amplitude seemingly a “muffler layer” and not a desirable flexible base protection as well? Currently I dedicate myself to: Step 1 - free plate tuning/modal chandling analysis. 2 Step - At each stage of gluing/assembling the pieces I make measurements to check dynamic changes in the set that is born I use the chandling analysis, as observed by Edward C Campbell, to correct any changes generated by extra weight of the new pieces such as ribs, blocks, etc. 3- At the end of the process, I apply the final body tuning system; in order to tune the dynamic behavior of the ensemble, by Robert Zuger in order to obtain the hierarchical balance and potential frequencies of the ensemble, with the help of software like "audacity", so I can choose and model the sound. Method used by looking at the regions that can be slightly altered to obtain a more balanced response of harmonics and note center based on the fundamental pitch. 4- I suppose that preserving the mechanics of the wood and using oil varnish because it is more elastic, this seems better to me, I don't understand the artificial process of plasticizing the wood, to protect it, how about using something more flexible? P.S. I know it's a very difficult question to understand, sorry for my difficult English. All the best!
I'm sorry, but there are too many questions all in a row and I'm just a luthier, you probably need a physicist to get more appropriate answers, and honestly, for some aspects you ask I don't think an effective answer can be given, there are too many variables that come into play to be sure. Anyway, I would like to try to clarify some points, within the limits of my personal opinion. Casein is by no means dead weight, or a brake, as the weight gain it causes is infinitesimal when used properly (less than half a gram on an about 60g spruce plate), so I would say negligible. Then the casein compacts the surface creating a harder surface layer, improving the surface tension and transmission of vibrations, which in my opinion is positive even if honestly I cannot give an in-depth scientific answer of this phenomenon. The rest of the varnish must be hard and stiff, so as not to dampen the vibrations, even if in a so thin layer that it does not block them. Oil varnishes or alcohol varnishes are equivalent, because both can have very different characteristics depending on the composition: you can make an oil varnish that is too hard or too soft, and the same goes for the alcohol one, the key lies in the right balance and quality of ingredients and cooking systems. Often poorly formulated oil varnishes are the worst because they remain too soft due to the composition or because they do not dry well, they will absorb vibrations with a strong muffling effect on sound. The same goes for alcohol varnishes that contain excessive amounts of essential oils that never dry out properly making them too soft and absorbing vibrations with the same bad effect on sound. The scientific approach to work contains some interesting aspects, developing a knowledge of the functioning of the violin and its structure is fundamental, but in my opinion it cannot replace the ability to interpret the results based on our sensitivity, and on our manual skills, which I believe is still the fundamental aspect for obtaining good results, even if obviously scientific knowledge can help a lot. Since you mentioned Robert Zuger, I suggest you contact him and ask him the most technical questions, I know Robert well and he is very kind and helpful, and above all very good at simplifying complex technical explanations to make us poor luthiers understand them. I wanted to keep it short, but in the end I couldn't, sorry for the long winded answer.😊
@@DavideSora Thanks Davide, it was enough for my conclusions. About the weight, I referred to the weight in the dynamic behavior due to mechanical changes in the surface of the wood, considering an absorption of how much, maybe 20/30%? P.S Yes, Robert Zugue is very clear in his explanations, I already talked a lot with him when he was at my house here in Brazil for a week, in Italy, and when I went to his house in 2008 for a week. I agree with using intuition for luteria, and I also like my specimeter, weight scale and my speaker with audacyti, as they show me values such as weight, measure and figures from chandling analysis, from these values I use my intuition , eliminating the concurrence of the variables to the maximum, to make my life easier! Thank you again! All the best Ivâ Labussière website atelierlabussiere
Dear Davide! Thank you for sharing your perfect work with us! I would like to ask, how do you reach the golden cinnamon colour of the violin before the varnish aplied, and how do you "pop up" the flames/grains?
The first step is to make the wood shine through proper use (it's not easy) of very sharp scrapers for finishing. Then the cinnamon color comes mainly from oxidation through exposure to UV light, which tans the wood. With the application of casein, further oxidation takes place which darkens the colors further, increasing the contrast of the grain
Hello maestro Davide, I didn't see you sanding the surface after you finished the casein process in the end of the video, you mentioned "remain rough" is that mean keep rough, don't sand the surface? Thank you!
Dear Davide, would this casein sealer (and the mastic ground applied afterwards) be OK to use under an oil varnish? (still waiting for my linseed oil to turn into linoxin :) so experimenting with oil in the mean time).
Dear Davide, thank you as ever for generously sharing all your knowledge! I have a question and haven't found it discussed in the thread so far: Do you use the same recipe for sizing the violin from inside? Many luthiers recommend that to improve the sound and stability to humidity and I wonder if a different solution should be used for that or whether it should be just the same. Many thanks!!
The same recipe is used both inside and outside. It also serves, in addition to the reasons you mention, to compensate for the tensions that would be created by applying it on one side only
Yes, you can see how I finish the neck here: ruclips.net/video/3JGFLx6uG_E/видео.html Here you can see the preparation of the stain: ruclips.net/video/8183e47m-bs/видео.html
Good Morning Master, Hope that you are well. I would like to know if the casein in the sealer could be replaced with whey protein. Have you or anyone ever tried to use it?Than you again for your generous teachings. I am at the stage of sealing and varnishing my first violin. Everything I know I learned from you master. Thank you.
I don't know, I have never tried whey protein but I assume that being proteins they will behave similar to casein, albumin, or hide glue. Tests should be done to understand their solubility, moisture resistance, dry film stiffness and so on, which could be different from other proteins, or similar, who knows. I use casein mainly for its film stiffness and especially for its moisture resistance especially when used in combination with calcium hydroxide (lime). Also because it has always been used since ancient times as a glue or as a medium for paintings.
@Davide Sora Thank you for the quick response Master. I understand. As I don’t have the skill to determine those those physical properties, I will just follow the proven way and use casein. Thank you.
Thank you for showing this process. Would Ammonia solution of 25% work? I have been looking to purchase Ammonia but seem only to find 25% concentration.
Hello dear master, As always thank you so much for your priceless lessons of knowledge lessons. I seal the wood with a mastic before and its make the wood come alive and shine does the casein have the same effect?
The effect of the mastic directly on the wood is unmatched, the casein is not so bright. But if you use very diluted casein (4% concentration) the film will be so thin as to be practically irrelevant aesthetically. I put the casein first and then the mastic, in this way there is not a big difference, with the advantage of benefiting from the stiffening effect of the casein. Also, the wood will have a darker color with casein, which gives another small advantage to the final color of the varnish. But if extreme shine is the most important thing for you, just stick with the mastic only and don't use casein. Mastic also has the advantage that it does not raise the grain, while casein which is water-based does. This may or may not be desired, it depends on your goal about the final aspect of the varnish. you can also put casein only on the spruce and not on the maple to maximize flames brightness, there are many possibilities
When dry the appearance is opaque, but this is mainly due to the high dilution which prevents the formation of a layer. It "seals" only the wood fibers leaving the surface slightly rough, this creates the scattering of light which does not make it appear shiny. About the color, it alters it with a light yellowing and by increasing the contrast of the figures, this is one of its intended purposes. It does not darken much but does not leave the wood with an unaltered color.
Hi Davide, just to be sure: Is the mixture (1.5 g casein + 15 g destilled water + 4.5 ml 30% ammoniaca + 18 ml limewater) already the 4% solution? Or has this mixture to be deluted to 4%? Many thanks! Georg
Just one, insisting more in the areas of greater absorption of the top plate (end-grain wood). A too thick layer may give adhesion problems to the varnish. The casein does not have to form a superficially visible layer, just seal the fiber and the pores without filling them. A very very thin coat. For this reason I apply it at a very low concentration (only 4% solid content)
Buon Giorno Davide! My question is related to Cello-varnishing. Is the procedure for Cello the same? More specifically do you apply the same UV-tanning cycles as for violine? No problems with neck distortion? Or do you tann only the box? Graie e buana giornata! Georg
Yes, the procedure is the same for the cello too. Problems with neck distortion are accentuated with the cello, but if the neck wood has the grain perfectly parallel to the top there are usually no problems with twist (the worst), which occurs if the grain is slanted or irregular. Leaving a thicker fingerboard gluing platform helps to arrange things eventually. Tanning the soundbox and neck separately is also a recommended procedure.
Hi Davide, Does the wide 25:1 water to casein dilution ratio serve to reduce the stresses on the violin and prevent cracking when dry? Thank you for sharing your great knowledge with us. You are very kind to do so. Regards, Steve
The purpose of the high dilution of the casein is to allow penetration into the surface without the formation of a thick and glassy layer which would be detrimental for various reasons, including what you say. But even at this low dilution there is a stiffening of the wood and of the surface not to be underestimated. If some ghost crack was already present in the wood it will certainly open.
Hello teacher. Please help me. I have found water soluble lactose casein. Is there such a thing? And if so will I use ammonia and lime water? thank you.
I don't know what lactose casein is, but if it is already soluble in water there is no need to use ammonia. I use pure casein (lactose-free) and there is a need for a strong base to dissolve it, I use ammonia but other bases can work. This is the casein I use: www.kremer-pigmente.com/en/mediums-binders-und-glues/water-soluble-binders/mediums-und-natural-gums/2083/casein Some violin makers get the casein directly from low-fat milk or low-fat cheese (Quark). Another good alternative to casein is albumin (the liquid deposit of whipped egg white ), only to be diluted with water.
@@DavideSora Good evening Maestro Davide. I make just my second violin and I want to use albumina for the experience. Can you tell me what must be the dilution with water? Thank you 😊!
When I used albumin (a few decades ago) I made it starting from fresh egg white, which is whipped and left to rest for a few hours, until a liquid settles at the base of the jar. This liquid is what you use, I diluted it 50% with distilled water to use it. But given the already liquid nature and the difference in albumin content of natural eggs, it is difficult to understand the final concentration, so I have no idea what it is if you use the powdered albumin that is used on the market. But intuitively, being proteins I believe that the concentration may be equal to that of the casein or of the hide glue, that is 4% or 5% max.
Salve Davide una domanda, nel legno di testa compresa la parte superiore e inferiore della sesta della bombatura della tavola (che dovrebbe avere il poro più aperto credo) insisti di più con la caseina? Grazie
Si, quando la applico insisto fino a che non assorbe più completamente in quelle zone (dove i pori si presentano parzialmente di testa) e rimane uniforme come il resto della tavola
Casein is very similar to Albumin (they are both proteins), which is the main component of the "Vernice bianca". My feeling is that Casein stiffens the wood more than Vernice bianca that also contains other less hard substances such as gum arabic, sugar and honey. For me Vernice bianca is food for woodworm 😊 and I don't like this, casein with its chemical components such as calcium hydroxide and especially if borax is used has instead a preservative effect that I like and make more sense for me.
@@DavideSora Then what do you think of propolis for inside? Its seems to be very hydrophobic, but I'm in doubt for its usege as repairs could be very problematic in the long term. And is this lime and borax usage based on old formulations or your own recipe?
@@ozgundemirr Using resins or waxy substances inside is never a good idea exactly for the reasons you say. I use the same casein that I put outside, also for the reason to compensate for the tensions it causes by balancing them on both sides (inside and outside). Casein and proteins in general are perfectly compatible with the glue, so no problem with future repair. Borax is a substance used since ancient times as a preservative against mold and insect attack, so it is very likely that there are ancient recipes. Unfortunately I haven't found any specifics recipe yet (you can't find almost anything specific for violins in old text) but it can be used instead of ammonia or calcium hydroxide to dissolve casein. I haven't tried to do it yet, for now I have only tried the borax casein that sells Kremer (Schminke). it works fine but for the moment I still prefer my ammonia calcium casein because it has a property of stiffening the wood more, that of Kremer with borax is more elastic but less stiff, more similar to the characteristics of stiffness / elasticity of albumin. I would try to make a casein with borax and calcium that should increase the intrinsic stiffness, but I haven't found the time yet. It must be said that these differences are small and is difficult to establish the greater or lesser effectiveness, many tests and a lot of patience are needed (time). Ah, in the previous post I forgot to say that casein is fine for both oil and alcool varnish, the only minor drawback (like with all other protein size) is that the varnish splinters more easily from the wood substrate due to the reduced adhesion they cause.
For curing oil varnishes, you need UV and oxygen, but air circulation through holes at the top and at the bottom is enough. No ventilation is needed. It would be essential if the box was airtight, but mine is not.
You can keep it for about a week in the refrigerator, you have to make it fresh for each violin. To keep it longer you should add anti-rot preservatives, but for me it's better not to do it, I don't like "strange" chemical substances on my violin.
@@petrrohlik4316 I have never tried to freeze it, but I think to make it fresh every time you are more confident that it retains its properties, the work is not much and if you have a precise scales it is possible to make small quantities so as not to waste too much. But it could work, you should do a test by letting it dry on a plastic sheet after thawing it, to evaluate if the dry film remains as stiff as if prepared fresh or if you can feel a difference
Dear mr. Sora, If I may ask: Do you leave it to rest so the ammonia can evaporate? Or do you not mind about the ammonia resting in the caseïn? And as for a porefiller, what would you advise over the casein? Grazie!
I let it rest so that ammonia and hydroxide act thoroughly dissolving the casein well, but the jar must be tightly closed so that there is no evaporation of the alkalis. Ammonia will be left to evaporate completely after application of the casein on the violin, until its typical pungent smell will no longer comes out from the wood (doesn't take much time because the quantity is minimal). As a pore filler I use a resinous sealer based on mastic and cooked colophony dissolved in rectified turpentine essence (16% resins, 84% turpentine) to which I add from 10% to 30% of pumice which is the actual pore filler. The percentage of pumice varies depending on the wood, if the pores are very small and the density of the wood is high it can also be completely omitted, but normally with medium/low density wood I use I put about 20%. These percentages are indicative as the quantity is corrected by eye according to the sensations during some application tests (fluidity, grittiness, penetration, etc.) and the solvent evaporate with time spoiling the ratio.
@@mesimerisnikos The acoustic and aesthetic effects cannot be separated and must be positive in both cases. Substances in contact with wood must have an appropriate refractive index (very similar to that of wood) and mastic and colophony are great in this sense, creating a very refractive effect. From the acoustic point of view they do not lead to improvements, but the important thing is that they do not cause deterioration by behaving "transparently" (no negative effects=positive effect). Casein, on the other hand, acts as a stiffener of the wood, causing, in my opinion, an effective and recognizable acoustic effect.
Dewaxed shellac may work fine but I think a water protein sealer work best, as it combines better with wood occupying the same chemicals bonds where water coming from atmospheric humidity would bind, reducing the hygroscopicity of wood. I'm not sure that shellac does the same. Another reason is that chemical analyzes on ancient Cremonese instruments never find shellac in contact with wood, but find proteins instead. A shellac sealer is of more recent use, comes especially from guitar work.
Hello and thanks alot for you help!I would like to know where i can find lime water...u mean something like Perrier? What concentration of it?Also is there a different recipe if i would like to use it as a sealer also?
To make lime water you have to take slaked lime and dilute it with distilled water, mix it well and let it settle, so that a layer of transparent water of a couple of centimeters is formed over the slaked lime paste. This is lime water, i.e. a saturated solution of calcium hydroxide. You can buy good quality slaked lime from Kremer Pigment : shop.kremerpigments.com/en/fillers-und-building-materials/limes/4894/pit-lime but any good and aged slaked lime does the work if it does not contain some synthetic additives. What you see in the video is in fact a very diluted sealer, it coats and seals the fibers and pores but without filling them, it only serves to avoid the penetration of the subsequent layers of varnish. If you like to improve the filling properties you have to increase the concentration of casein and maybe add inert fillers like chalk, kaolin, pumice or diatomaceous earth (etc.), but there will be a loss of transparency most likely. I don't do it because it would become excessively hard and stiff and very probably may give problems of adhesion to the next layers of varnish.
Sorry for disturbing again but it tried to find ammonia with no luck...only food ammonia in a dust form..will it be the same? It says ammonium bicarbonate
@@AlexandrosNikolakis I don't know, I've never tried it, but I think it's not strong enough to dissolve casein. I use concentrated ammonia (30%), perhaps you can find some more diluted ammonia for floor cleaning at the supermarket, or try to order concentrated ammonia online, but I don't know if there are problem with the shipment. You may try in some shop that sells items for restoration or for paints. Casein can be dissolved by any strong base, not only ammonia, but of course the result is slightly different. For example, you can use slaked lime (not lime water only) but the result will be casein glue, a very strong and waterproof glue used by ancient maker. In a diluted version it may work as a sealer coat, but a lot stiffer and with strong filling action. Also borax may be used to dissolve casein. What you get is respectively ammonium caseinate, calcium caseinate and borax caseinate and so on. If you do not manage to dissolve casein, you can use albumin as an alternative, I use it for many years before skipping to casein, and it work well too.
@@DavideSora to tell the truthy casein states on the outside that it is water soluble...maybe i have the wrong type?i managed to get the ammonia and the lime water...
Hi Davide! I tried a casein sealer made of calcium and casein, but somehow the calcium didn't make the casein dissolve properly, it stayed somewhat granular, and I think I just had a bad kind of calcium. I used calcium carbonate, do you know what kind of calcium I should have used? But anyway, I suppose this works the same way? I really liked what the calcium did to the surface, but having a good amount of base in this will probably make it react with the wood in a similar fashion to calcium, which seems to tan/oxidise the surface, right? In that case this might be easier to do for me. Can it be stored in solution or do you have to use it all within a day or so? Best regards, Tobias
If it remains granular it is not good, it must dissolve completely. To dissolve casein with calcium you need calcium hydroxide, it would be better to use real slaked lime ( www.kremer-pigmente.com/en/shop/fillers-building-materials/limes/31800-pit-lime.html ) and in a rather high quantity, normally 3 parts of lime per 4 parts of casein by weight. This was formerly casein glue, which is an excellent sealer when diluted with water. The alkalinity of the slaked lime (calcium hydroxide) gives color to the wood by oxidation of the tannins. Given its alkaline nature, it keeps quite long but it is always better to keep it in the refrigerator. In any case, freshly made is always the best thing, otherwise when it is old it is advisable to do some tests before using it to see if it still works. If the smell changes, it's no longer good.
Thank you so much! I have been looking for the right calcium compound for so long, but there it is! I realise that the granular casein is no good, since it is not in solution and therefore wipes right off rather than seal the wood. My suspicion is that the basicity of this food grade stuff is just not enough to change the casein into its soluble conformation. What I made with calcium carbonate was quite exothermic in solution and started curing like plaster, so that could not be stored, that's for sure. But yeah, maybe making a fresh batch is better to make sure the protein is stable either way? The oxidation is important to me. I'm making a cello (I think you replied to a thread on Maestronet about my top joint), and in a student apartment there isn't quite room to make proper UV box for it, so chances are the calcium is the only tanning it'll get prior to varnshing, unless I can figure something out with a growth tent. I'll go look for a source of calcium hydroxide or similar. I have plenty of time, as only the top plate and ribs are even close to assembly at this point Best regards, Tobias
@@Tostra1997 The casein made with lime actually makes a good color, you can also look at the method used by this luthier who uses lime and quark cheese as a source of casein : www.thestradsound.com/varnish He is also a maestronetters, so if you wish you can contact him on the forum to ask for more information
Thanks! That's quite smart. I made some from skim milk and bought some to compare, and honestly, even though the home made stuff seems equally pure to me (biotech engineer, not chemist), grinding it was not fun. Using quark eliminates that issue, even though it might not be as pure... I suppose it isn't an issue though? And yes, I like the colouring. I'll be adding a small amount of nut stain to mine, but the calcium alone seems to give a nice tan I'll keep this link and maybe try it on a few test pieces before I decide.
@@Tostra1997 Probably the lesser purity could make the final film more elastic due to a possible presence of fat (but I really don't know). The adding of a few drops of oil should also serve this purpose. I don't put any oil because I want to maximize the stiffening property, but I haven't done many tests with the added oil
Hi Davide, thanks for all your great videos. I have a question: where do you get your casein powder? I can't find it for sale anywhere! Thanks for you amazing channel and insights.
Teacher, I have a question. Distilled water is just for soaking the casein? So I have to add only water 36g more? or Both are totally saperated process?
You soak 1,5 g casein in 15 g distilled water overnight. Then add 4,5g ammonia and 18 g lime water. 15+4,5+18 = 37,5 g is the total amount of water you have in the solution that with a 1,5g casein content it results in about 4% concentration. No more water must be added, all water is distilled water.
Grazie Maestro !! I saw in maestronet a picture of the ground of one of your viola, probably the most beautiful ground I never seen. In this case you used mastic resin for sealing wood, why have you used casein intead of mastic in this instrument? Grazie mille !!
I always use Casein first as a sort of sealer and then Mastic in turpentine as a sort of refractive ground. I also put some Pumice in the mastic (up to 20%) as a filler for the pores. It doesn't close them completely but it helps. The color of the ground you saw on Maestronet is mostly UVA exposure (about 300 hours) improved by the effect of the Casein and Mastic if I remember correctly.
@@DavideSora Thanks a lot for the details and explanation ! I hope that soon I could have the opportunity to see an instrument of yours live, but in the photos they looks extraordinarily beautiful.
@@DavideSora Hi Maestro Davide. Can you give us the recipe of this Mastic refractive ground and how it is applied? I am an amateur violin maker and your help is invaluable. Thanks in advance.
@@mesimerisnikos If you had read the comments below you would have already found the answer. Anyway, I'll copy and paste it below for your convenience: The Mastic solution is basically a refractive ground, and is prepared simply by dissolving the resin in turpentine essence, with a concentration of 16% by weight (16% mastic - 84% turpentine). I also add some pumice to act as a pore filler, but this can be omitted. It is applied with a brush and immediately afterwards the excess is removed with a rag soaked in alcohol, so that it does not form a glossy surface layer but remains only inside the surface. At least 12 hours in the UV lamp will be needed to let it dry (even 24 hours, depending on the type and power of the lamps), otherwise it is better to wait up to a week without a UV lamp. Once perfectly dry, you are ready to apply the varnish.
Per solubilizzare la caseina in acqua è necessario utilizzare una sostanza alcalina, le più utilizzate sono la calce (idrossido di calcio) e l'ammoniaca. Una volta sciolta con queste sostanze basiche la caseina si trasforma nei rispettivi caseinati di calcio e di ammonio. Io le utilizzo entrambe, ma ad esempio la colla di caseina utilizzata anticamente era fatta solo con la calce (caseinato di calcio) e in quantità molto maggiore alle dosi che indico nella mia ricetta, formando una pasta densa con un forte potere collante e caratteristiche di irreversibilità a causa della presenza del calcio che la rende resistente all'acqua. Con la sola ammoniaca (caseinato di ammonio) questa caratteristica di resistenza all'acqua è molto minore.
How did you get that nice wood color? UV-chamber + natrium nitrite, or is it stain? You can see your jar turn brown during the video. Anyways a really good base color I think, very beautiful. Also the gloss of the grain is nice!
The wood color comes from about 200 hours in the UV box, I do not put any other treatment before the application of casein. The gloss comes from wood finishing technique, that is only scraper (no sandpaper) and a light final touch with horsetail (equisetum shave grass and horsehair brush). I don't know why casein becomes dark in the jar, I suspect it is an oxidation due to the presence of ammonia and calcium hydroxide, but I'm not a chemist. Would you have a better idea of what the cause could be? Anyway it stay transparent and contributes somewhat to the final color.
@@DavideSora Thank you very much for sharing! I enjoy your videos a lot. I guess I watched all of them :D. 200 hours of UV sounds a lot, but it looks like you get the most natural color tone this way. Other treatments may be faster, but I guess patience is one of the big players in violin making :). I tried natrium nitrite as an accelerator. It works over night, but the wood gets a note of orange, which I didn't like. I also use scrapers, but didn't try the horse hair brush. I will try! I'm quite at the beginning of my maker career, so I'm very grateful for every bit and piece, that leads me to my inner picture of the perfect violin. Thank you Maestro. All the best from Austria
@@DavideSora I would suppose the color in the casein jar gets browner, because of the small amounts of residue, the sponge removes from your violin while applicating. Even after the horsetail treatment, I guess there will be fine wood shavings, uv-brown in this case.
Yes, I also think that this is the most probable cause of the change in color of the casein that remains in the jar, I think it's also the cause of the slight darkening of the violin after the application, because the wood is left slightly acidified by the UV and reacts with the alkalies present in the casein sealer, which make a sort of neutralization of the ph which I believe is a good thing.
@@DavideSora very nice. thanks for all the great work, and sharing in the field. I have used Juncus effusus (corkscrew rush) and plan on growing a larger plot of it very soon ;)
Why don't you put the casein in a small bowl while you work so it's easier to soak the sponge? You could always pour back any you'd like to save in the jar afterward...
It is not calcium hydrochloride, but it is calcium hydroxide, which is the common lime that was used long before 1700. At the time of Stradivari, every woodworker used casein mixed with lime to make the glue commonly called cheese glue, making it from cheese or curdled milk and lime. This glue, simply diluted with water or perhaps even with ammonia in the form of animal or even human urine (the purest one was that of children, as written in several ancient manuscripts on painting😊) it may actually be very similar to the one I use, even if it is impossible to know for sure how they made it, as chemical analyzes can confirm the presence of some elements but they will never be able to tell us a recipe, or they cannot detect elements that evaporate without leaving significant traces such as the ammonia. However, there are many different ways to make a casein preparation, as practically any basic substance (alkaline) can dissolve it, including potassium hydroxide (lye made from wood ash) or Borax or many other elements with marked alkalinity
Dear Davide, my questions would be: when you write saturated solution of calcium hydroxide, what would be the % of powder in water, and secondly, as far as I know, casein is not soluble in water, so does it get dissolved in, because of ammonia and lime water, or you use a different one? Meantime, I would thank you so much for sharing your knowledge, and experience with us. We know how many hours you spend for it..! Gracie maestro!!
You are right, Casein is not water-soluble and you need a strong base to dissolve it, ammonia and calcium hydroxide is used for this purpose. You could also use only ammonia or only hydroxide, but in the first case it would be less resistant to humidity and in the second case it would take too much to dissolve the casein and you would get casein glue, which was used by ancient luthiers to glue the central joints of the violin plates and the ribs to the blocks (it's really a water-resistant glue, today it is no longer used because it is a non-reversible glue and would make restoration operations very troublesome). To make the saturated solution of hydroxide I don't know what the stoichiometric quantity is, simply add excess hydroxide to distilled water until an abundant residue forms on the bottom of the jar and use the clear water above (lime water), check the pH with an indicator and it should give you at least pH 12 (dark blue color on the litmus paper). I don't use pure calcium hydroxide powder but I use real lime, that is Pit lime aged 5 years bought from Kremer : www.kremer-pigmente.com/en/fillers-und-building-materials/limes/529/pit-lime?number=31800
Votre sens du détail et de la perfection font de vos vidéos une très precieuse source d'inspiration pour tous les luthiers - dont moi ! Merci…
Another excellent video. Other luthiers tell you to use casein but you give us the recipe, application materials, drying methods etc. etc. Many thanks.
From the comments on this video, I understood that after applying the casein, apply mastic. In this regard, I would like to ask you two questions: how is the mastic solution that you apply prepared? After this mastic solution, do you apply anything else before linoxyn varnish?
The Mastic solution is basically a refractive ground, and is prepared simply by dissolving the resin in turpentine essence, with a concentration of 16% by weight (16% mastic - 84% turpentine).
I also add some pumice to act as a pore filler, but this can be omitted. It is applied with a brush and immediately afterwards the excess is removed with a rag soaked in alcohol, so that it does not form a glossy surface layer but remains only inside the surface. At least 12 hours in the UV lamp will be needed to let it dry (even 24 hours, depending on the type and power of the lamps), otherwise it is better to wait up to a week without a UV lamp. Once perfectly dry, you are ready to apply the varnish.
Thank you Dear Davide, for sharing your beautiful and inspiring work.
Please allow me to learn from your analytical answer?
What's the difference in having a dead body "caseinate" (dead, because it doesn't have adequate mechanics to emit vibrations but it changes the wood with its weight in a significant way, in addition to behaving like a stiffening plastic seal, brake and amplitude brake. This seems with a wave compressor.
Why not use, for example, a rigid varnish over the instrument? I notice that both modified the stiffness of the part, like a brake/compressor of amplitude and waves?
Principle of observation and consideration for this question:
Oil Varnish Vs. Indian lacquer varnish + resins. Thinking that the choice of oil varnish is common for having preferable elastic and aesthetic characteristics for acoustic equalization? So what's the use of using a sealant that promotes “brake, brake” and low amplitude seemingly a “muffler layer” and not a desirable flexible base protection as well?
Currently I dedicate myself to:
Step 1 - free plate tuning/modal chandling analysis.
2 Step - At each stage of gluing/assembling the pieces I make measurements to check dynamic changes in the set that is born I use the chandling analysis, as observed by Edward C Campbell, to correct any changes generated by extra weight of the new pieces such as ribs, blocks, etc.
3- At the end of the process, I apply the final body tuning system; in order to tune the dynamic behavior of the ensemble, by Robert Zuger in order to obtain the hierarchical balance and potential frequencies of the ensemble, with the help of software like "audacity", so I can choose and model the sound. Method used by looking at the regions that can be slightly altered to obtain a more balanced response of harmonics and note center based on the fundamental pitch.
4- I suppose that preserving the mechanics of the wood and using oil varnish because it is more elastic, this seems better to me, I don't understand the artificial process of plasticizing the wood, to protect it, how about using something more flexible?
P.S. I know it's a very difficult question to understand, sorry for my difficult English.
All the best!
I'm sorry, but there are too many questions all in a row and I'm just a luthier, you probably need a physicist to get more appropriate answers, and honestly, for some aspects you ask I don't think an effective answer can be given, there are too many variables that come into play to be sure. Anyway, I would like to try to clarify some points, within the limits of my personal opinion. Casein is by no means dead weight, or a brake, as the weight gain it causes is infinitesimal when used properly (less than half a gram on an about 60g spruce plate), so I would say negligible. Then the casein compacts the surface creating a harder surface layer, improving the surface tension and transmission of vibrations, which in my opinion is positive even if honestly I cannot give an in-depth scientific answer of this phenomenon. The rest of the varnish must be hard and stiff, so as not to dampen the vibrations, even if in a so thin layer that it does not block them. Oil varnishes or alcohol varnishes are equivalent, because both can have very different characteristics depending on the composition: you can make an oil varnish that is too hard or too soft, and the same goes for the alcohol one, the key lies in the right balance and quality of ingredients and cooking systems. Often poorly formulated oil varnishes are the worst because they remain too soft due to the composition or because they do not dry well, they will absorb vibrations with a strong muffling effect on sound. The same goes for alcohol varnishes that contain excessive amounts of essential oils that never dry out properly making them too soft and absorbing vibrations with the same bad effect on sound. The scientific approach to work contains some interesting aspects, developing a knowledge of the functioning of the violin and its structure is fundamental, but in my opinion it cannot replace the ability to interpret the results based on our sensitivity, and on our manual skills, which I believe is still the fundamental aspect for obtaining good results, even if obviously scientific knowledge can help a lot.
Since you mentioned Robert Zuger, I suggest you contact him and ask him the most technical questions, I know Robert well and he is very kind and helpful, and above all very good at simplifying complex technical explanations to make us poor luthiers understand them.
I wanted to keep it short, but in the end I couldn't, sorry for the long winded answer.😊
@@DavideSora Thanks Davide, it was enough for my conclusions.
About the weight, I referred to the weight in the dynamic behavior due to mechanical changes in the surface of the wood, considering an absorption of how much, maybe 20/30%?
P.S
Yes, Robert Zugue is very clear in his explanations, I already talked a lot with him when he was at my house here in Brazil for a week, in Italy, and when I went to his house in 2008 for a week.
I agree with using intuition for luteria, and I also like my specimeter, weight scale and my speaker with audacyti, as they show me values such as weight, measure and figures from chandling analysis, from these values I use my intuition , eliminating the concurrence of the variables to the maximum, to make my life easier!
Thank you again!
All the best
Ivâ Labussière
website atelierlabussiere
Dear Davide! Thank you for sharing your perfect work with us!
I would like to ask, how do you reach the golden cinnamon colour of the violin before the varnish aplied, and how do you "pop up" the flames/grains?
The first step is to make the wood shine through proper use (it's not easy) of very sharp scrapers for finishing. Then the cinnamon color comes mainly from oxidation through exposure to UV light, which tans the wood. With the application of casein, further oxidation takes place which darkens the colors further, increasing the contrast of the grain
Thank you for the English translations in your videos. I understand some Italian, but it’s better in my second language!
Hello maestro Davide,
I didn't see you sanding the surface after you finished the casein process in the end of the video, you mentioned "remain rough" is that mean keep rough, don't sand the surface?
Thank you!
Yes, a bit of roughness Is good to get a 3D effect of the wood under the varnish
Dear Davide, would this casein sealer (and the mastic ground applied afterwards) be OK to use under an oil varnish? (still waiting for my linseed oil to turn into linoxin :) so experimenting with oil in the mean time).
Yes, there are no contraindications, I used them with oil varnish too
Dear Davide, thank you as ever for generously sharing all your knowledge! I have a question and haven't found it discussed in the thread so far: Do you use the same recipe for sizing the violin from inside? Many luthiers recommend that to improve the sound and stability to humidity and I wonder if a different solution should be used for that or whether it should be just the same. Many thanks!!
The same recipe is used both inside and outside. It also serves, in addition to the reasons you mention, to compensate for the tensions that would be created by applying it on one side only
@@DavideSora Thank you so much!! Incredible how fast you answer to all these questions!
Grazie Maestro!
Grazie Maestro...
So the casein goes on the neck, too.
Would an organic stain (if used) and a refractive ground go on the back of the neck also?
Yes, you can see how I finish the neck here:
ruclips.net/video/3JGFLx6uG_E/видео.html
Here you can see the preparation of the stain:
ruclips.net/video/8183e47m-bs/видео.html
grazie mille!
Simplesmente perfeito!!!!
Good Morning Master, Hope that you are well. I would like to know if the casein in the sealer could be replaced with whey protein. Have you or anyone ever tried to use it?Than you again for your generous teachings. I am at the stage of sealing and varnishing my first violin. Everything I know I learned from you master. Thank you.
I don't know, I have never tried whey protein but I assume that being proteins they will behave similar to casein, albumin, or hide glue. Tests should be done to understand their solubility, moisture resistance, dry film stiffness and so on, which could be different from other proteins, or similar, who knows. I use casein mainly for its film stiffness and especially for its moisture resistance especially when used in combination with calcium hydroxide (lime). Also because it has always been used since ancient times as a glue or as a medium for paintings.
@Davide Sora Thank you for the quick response Master. I understand. As I don’t have the skill to determine those those physical properties, I will just follow the proven way and use casein.
Thank you.
Thank you for showing this process. Would Ammonia solution of 25% work? I have been looking to purchase Ammonia but seem only to find 25% concentration.
I think so, at the worst it will take a slightly higher quantity or a little more time
Davide Sora Thank you, and also thank you for showing how to make the violins its very generous of you to share this knowledge.
Hello dear master,
As always thank you so much for your priceless lessons of knowledge lessons.
I seal the wood with a mastic before and its make the wood come alive and shine does the casein have the same effect?
The effect of the mastic directly on the wood is unmatched, the casein is not so bright.
But if you use very diluted casein (4% concentration) the film will be so thin as to be practically irrelevant aesthetically. I put the casein first and then the mastic, in this way there is not a big difference, with the advantage of benefiting from the stiffening effect of the casein. Also, the wood will have a darker color with casein, which gives another small advantage to the final color of the varnish. But if extreme shine is the most important thing for you, just stick with the mastic only and don't use casein. Mastic also has the advantage that it does not raise the grain, while casein which is water-based does. This may or may not be desired, it depends on your goal about the final aspect of the varnish. you can also put casein only on the spruce and not on the maple to maximize flames brightness, there are many possibilities
Thank you very much ❣️
Grazie!!
Hello, just wondering how the finish looks when dry. I'm trying to find a wood sealer that is matte and does not alter wood colour if possible thanks!
When dry the appearance is opaque, but this is mainly due to the high dilution which prevents the formation of a layer. It "seals" only the wood fibers leaving the surface slightly rough, this creates the scattering of light which does not make it appear shiny. About the color, it alters it with a light yellowing and by increasing the contrast of the figures, this is one of its intended purposes. It does not darken much but does not leave the wood with an unaltered color.
@@DavideSora Thank you, your work looks beautiful.
Hi Davide, just to be sure:
Is the mixture (1.5 g casein + 15 g destilled water + 4.5 ml 30% ammoniaca + 18 ml limewater) already the 4% solution?
Or has this mixture to be deluted to 4%?
Many thanks!
Georg
It is already at 4%, considering the total liquids including ammonia and lime water compared to dry casein. No need to dilute it further.
Hello hello. Here we are again.Please can you tell us how many layers you pass with casein (inside and outside)? GRAZIE MILLE.
Just one, insisting more in the areas of greater absorption of the top plate (end-grain wood). A too thick layer may give adhesion problems to the varnish. The casein does not have to form a superficially visible layer, just seal the fiber and the pores without filling them. A very very thin coat. For this reason I apply it at a very low concentration (only 4% solid content)
@@DavideSora Thank you once again.
Buon Giorno Davide! My question is related to Cello-varnishing. Is the procedure for Cello the same? More specifically do you apply the same UV-tanning cycles as for violine? No problems with neck distortion? Or do you tann only the box? Graie e buana giornata! Georg
Yes, the procedure is the same for the cello too. Problems with neck distortion are accentuated with the cello, but if the neck wood has the grain perfectly parallel to the top there are usually no problems with twist (the worst), which occurs if the grain is slanted or irregular. Leaving a thicker fingerboard gluing platform helps to arrange things eventually. Tanning the soundbox and neck separately is also a recommended procedure.
Thanks a lot Davide for your immediat answer.
Hi Davide,
Does the wide 25:1 water to casein dilution ratio serve to reduce the stresses on the violin and prevent cracking when dry? Thank you for sharing your great knowledge with us. You are very kind to do so.
Regards,
Steve
The purpose of the high dilution of the casein is to allow penetration into the surface without the formation of a thick and glassy layer which would be detrimental for various reasons, including what you say. But even at this low dilution there is a stiffening of the wood and of the surface not to be underestimated. If some ghost crack was already present in the wood it will certainly open.
Thanks very much Davide.
Hello teacher. Please help me. I have found water soluble lactose casein. Is there such a thing? And if so will I use ammonia and lime water?
thank you.
I don't know what lactose casein is, but if it is already soluble in water there is no need to use ammonia. I use pure casein (lactose-free) and there is a need for a strong base to dissolve it, I use ammonia but other bases can work.
This is the casein I use: www.kremer-pigmente.com/en/mediums-binders-und-glues/water-soluble-binders/mediums-und-natural-gums/2083/casein
Some violin makers get the casein directly from low-fat milk or low-fat cheese (Quark). Another good alternative to casein is albumin (the liquid deposit of whipped egg white ), only to be diluted with water.
@@DavideSora Thank you. Your help is invaluable.
@@DavideSora Good evening Maestro Davide. I make just my second violin and I want to use albumina for the experience. Can you tell me what must be the dilution with water?
Thank you 😊!
When I used albumin (a few decades ago) I made it starting from fresh egg white, which is whipped and left to rest for a few hours, until a liquid settles at the base of the jar. This liquid is what you use, I diluted it 50% with distilled water to use it. But given the already liquid nature and the difference in albumin content of natural eggs, it is difficult to understand the final concentration, so I have no idea what it is if you use the powdered albumin that is used on the market. But intuitively, being proteins I believe that the concentration may be equal to that of the casein or of the hide glue, that is 4% or 5% max.
@@DavideSora I will use your advise with egg white and 50% water. Thanks again.
Salve Davide una domanda, nel legno di testa compresa la parte superiore e inferiore della sesta della bombatura della tavola (che dovrebbe avere il poro più aperto credo) insisti di più con la caseina? Grazie
Si, quando la applico insisto fino a che non assorbe più completamente in quelle zone (dove i pori si presentano parzialmente di testa) e rimane uniforme come il resto della tavola
@@DavideSora grazie
Hello Davide, what do you think of this compared to Sacconi's vernice bianca? Also can this also be used for spirit varnishes?
Casein is very similar to Albumin (they are both proteins), which is the main component of the "Vernice bianca". My feeling is that Casein stiffens the wood more than Vernice bianca that also contains other less hard substances such as gum arabic, sugar and honey. For me Vernice bianca is food for woodworm 😊 and I don't like this, casein with its chemical components such as calcium hydroxide and especially if borax is used has instead a preservative effect that I like and make more sense for me.
@@DavideSora Then what do you think of propolis for inside? Its seems to be very hydrophobic, but I'm in doubt for its usege as repairs could be very problematic in the long term.
And is this lime and borax usage based on old formulations or your own recipe?
@@ozgundemirr Using resins or waxy substances inside is never a good idea exactly for the reasons you say. I use the same casein that I put outside, also for the reason to compensate for the tensions it causes by balancing them on both sides (inside and outside). Casein and proteins in general are perfectly compatible with the glue, so no problem with future repair.
Borax is a substance used since ancient times as a preservative against mold and insect attack, so it is very likely that there are ancient recipes. Unfortunately I haven't found any specifics recipe yet (you can't find almost anything specific for violins in old text) but it can be used instead of ammonia or calcium hydroxide to dissolve casein. I haven't tried to do it yet, for now I have only tried the borax casein that sells Kremer (Schminke). it works fine but for the moment I still prefer my ammonia calcium casein because it has a property of stiffening the wood more, that of Kremer with borax is more elastic but less stiff, more similar to the characteristics of stiffness / elasticity of albumin.
I would try to make a casein with borax and calcium that should increase the intrinsic stiffness, but I haven't found the time yet. It must be said that these differences are small and is difficult to establish the greater or lesser effectiveness, many tests and a lot of patience are needed (time).
Ah, in the previous post I forgot to say that casein is fine for both oil and alcool varnish, the only minor drawback (like with all other protein size) is that the varnish splinters more easily from the wood substrate due to the reduced adhesion they cause.
@@DavideSora Thank you very much for yout detailed explanations.
Do you actually only need UV(c) light to dry a oil based varnish? , or do you also need a ventilator to get rid of the heat in the cabine?
For curing oil varnishes, you need UV and oxygen, but air circulation through holes at the top and at the bottom is enough. No ventilation is needed. It would be essential if the box was airtight, but mine is not.
Hi, can you store this mixture for some time, or you have to mix new everytime you finish an instrument? Thank you!
You can keep it for about a week in the refrigerator, you have to make it fresh for each violin. To keep it longer you should add anti-rot preservatives, but for me it's better not to do it, I don't like "strange" chemical substances on my violin.
@@DavideSora I see, thanks for answer.. have you ever considered to freeze it? If not, do you think that would work? :)
@@petrrohlik4316 I have never tried to freeze it, but I think to make it fresh every time you are more confident that it retains its properties, the work is not much and if you have a precise scales it is possible to make small quantities so as not to waste too much. But it could work, you should do a test by letting it dry on a plastic sheet after thawing it, to evaluate if the dry film remains as stiff as if prepared fresh or if you can feel a difference
Dear mr. Sora, If I may ask: Do you leave it to rest so the ammonia can evaporate? Or do you not mind about the ammonia resting in the caseïn? And as for a porefiller, what would you advise over the casein? Grazie!
I let it rest so that ammonia and hydroxide act thoroughly dissolving the casein well, but the jar must be tightly closed so that there is no evaporation of the alkalis. Ammonia will be left to evaporate completely after application of the casein on the violin, until its typical pungent smell will no longer comes out from the wood (doesn't take much time because the quantity is minimal).
As a pore filler I use a resinous sealer based on mastic and cooked colophony dissolved in rectified turpentine essence (16% resins, 84% turpentine) to which I add from 10% to 30% of pumice which is the actual pore filler. The percentage of pumice varies depending on the wood, if the pores are very small and the density of the wood is high it can also be completely omitted, but normally with medium/low density wood I use I put about 20%. These percentages are indicative as the quantity is corrected by eye according to the sensations during some application tests (fluidity, grittiness, penetration, etc.) and the solvent evaporate with time spoiling the ratio.
@@DavideSora Hi master Davide. This pore filler is for visual use only or has acoustic effects? Thanks one more time.
@@mesimerisnikos The acoustic and aesthetic effects cannot be separated and must be positive in both cases. Substances in contact with wood must have an appropriate refractive index (very similar to that of wood) and mastic and colophony are great in this sense, creating a very refractive effect. From the acoustic point of view they do not lead to improvements, but the important thing is that they do not cause deterioration by behaving "transparently" (no negative effects=positive effect). Casein, on the other hand, acts as a stiffener of the wood, causing, in my opinion, an effective and recognizable acoustic effect.
@@DavideSora Αlways direct in the answers. Τhank you very much.
How come you use casein rather that dewaxed shellac as stain control?
Dewaxed shellac may work fine but I think a water protein sealer work best, as it combines better with wood occupying the same chemicals bonds where water coming from atmospheric humidity would bind, reducing the hygroscopicity of wood. I'm not sure that shellac does the same. Another reason is that chemical analyzes on ancient Cremonese instruments never find shellac in contact with wood, but find proteins instead. A shellac sealer is of more recent use, comes especially from guitar work.
Hello and thanks alot for you help!I would like to know where i can find lime water...u mean something like Perrier? What concentration of it?Also is there a different recipe if i would like to use it as a sealer also?
To make lime water you have to take slaked lime and dilute it with distilled water, mix it well and let it settle, so that a layer of transparent water of a couple of centimeters is formed over the slaked lime paste. This is lime water, i.e. a saturated solution of calcium hydroxide. You can buy good quality slaked lime from Kremer Pigment :
shop.kremerpigments.com/en/fillers-und-building-materials/limes/4894/pit-lime
but any good and aged slaked lime does the work if it does not contain some synthetic additives.
What you see in the video is in fact a very diluted sealer, it coats and seals the fibers and pores but without filling them, it only serves to avoid the penetration of the subsequent layers of varnish. If you like to improve the filling properties you have to increase the concentration of casein and maybe add inert fillers like chalk, kaolin, pumice or diatomaceous earth (etc.), but there will be a loss of transparency most likely. I don't do it because it would become excessively hard and stiff and very probably may give problems of adhesion to the next layers of varnish.
@@DavideSora thanks alot now i see what you mean! I will try it!!
Sorry for disturbing again but it tried to find ammonia with no luck...only food ammonia in a dust form..will it be the same? It says ammonium bicarbonate
@@AlexandrosNikolakis I don't know, I've never tried it, but I think it's not strong enough to dissolve casein. I use concentrated ammonia (30%), perhaps you can find some more diluted ammonia for floor cleaning at the supermarket, or try to order concentrated ammonia online, but I don't know if there are problem with the shipment. You may try in some shop that sells items for restoration or for paints. Casein can be dissolved by any strong base, not only ammonia, but of course the result is slightly different. For example, you can use slaked lime (not lime water only) but the result will be casein glue, a very strong and waterproof glue used by ancient maker. In a diluted version it may work as a sealer coat, but a lot stiffer and with strong filling action. Also borax may be used to dissolve casein. What you get is respectively ammonium caseinate, calcium caseinate and borax caseinate and so on. If you do not manage to dissolve casein, you can use albumin as an alternative, I use it for many years before skipping to casein, and it work well too.
@@DavideSora to tell the truthy casein states on the outside that it is water soluble...maybe i have the wrong type?i managed to get the ammonia and the lime water...
Hi Davide! I tried a casein sealer made of calcium and casein, but somehow the calcium didn't make the casein dissolve properly, it stayed somewhat granular, and I think I just had a bad kind of calcium. I used calcium carbonate, do you know what kind of calcium I should have used?
But anyway, I suppose this works the same way? I really liked what the calcium did to the surface, but having a good amount of base in this will probably make it react with the wood in a similar fashion to calcium, which seems to tan/oxidise the surface, right? In that case this might be easier to do for me.
Can it be stored in solution or do you have to use it all within a day or so?
Best regards, Tobias
If it remains granular it is not good, it must dissolve completely. To dissolve casein with calcium you need calcium hydroxide, it would be better to use real slaked lime ( www.kremer-pigmente.com/en/shop/fillers-building-materials/limes/31800-pit-lime.html ) and in a rather high quantity, normally 3 parts of lime per 4 parts of casein by weight. This was formerly casein glue, which is an excellent sealer when diluted with water. The alkalinity of the slaked lime (calcium hydroxide) gives color to the wood by oxidation of the tannins. Given its alkaline nature, it keeps quite long but it is always better to keep it in the refrigerator. In any case, freshly made is always the best thing, otherwise when it is old it is advisable to do some tests before using it to see if it still works. If the smell changes, it's no longer good.
Thank you so much! I have been looking for the right calcium compound for so long, but there it is! I realise that the granular casein is no good, since it is not in solution and therefore wipes right off rather than seal the wood. My suspicion is that the basicity of this food grade stuff is just not enough to change the casein into its soluble conformation.
What I made with calcium carbonate was quite exothermic in solution and started curing like plaster, so that could not be stored, that's for sure. But yeah, maybe making a fresh batch is better to make sure the protein is stable either way?
The oxidation is important to me. I'm making a cello (I think you replied to a thread on Maestronet about my top joint), and in a student apartment there isn't quite room to make proper UV box for it, so chances are the calcium is the only tanning it'll get prior to varnshing, unless I can figure something out with a growth tent.
I'll go look for a source of calcium hydroxide or similar. I have plenty of time, as only the top plate and ribs are even close to assembly at this point
Best regards, Tobias
@@Tostra1997 The casein made with lime actually makes a good color, you can also look at the method used by this luthier who uses lime and quark cheese as a source of casein : www.thestradsound.com/varnish He is also a maestronetters, so if you wish you can contact him on the forum to ask for more information
Thanks! That's quite smart. I made some from skim milk and bought some to compare, and honestly, even though the home made stuff seems equally pure to me (biotech engineer, not chemist), grinding it was not fun. Using quark eliminates that issue, even though it might not be as pure... I suppose it isn't an issue though?
And yes, I like the colouring. I'll be adding a small amount of nut stain to mine, but the calcium alone seems to give a nice tan
I'll keep this link and maybe try it on a few test pieces before I decide.
@@Tostra1997 Probably the lesser purity could make the final film more elastic due to a possible presence of fat (but I really don't know). The adding of a few drops of oil should also serve this purpose. I don't put any oil because I want to maximize the stiffening property, but I haven't done many tests with the added oil
Hi Davide, thanks for all your great videos. I have a question: where do you get your casein powder? I can't find it for sale anywhere! Thanks for you amazing channel and insights.
You can find it at Kremer: www.kremer-pigmente.com/en/shop/mediums-binders-glues/63200-casein.html
@@DavideSora thank you!!!
Please tell me what is the main function of calcium hydroxide. Thank you very much.
It helps the solubilization of casein and helps to make it more water-resistant once dry.
Teacher, I have a question. Distilled water is just for soaking the casein? So I have to add only water 36g more? or Both are totally saperated process?
You soak 1,5 g casein in 15 g distilled water overnight. Then add 4,5g ammonia and 18 g lime water. 15+4,5+18 = 37,5 g is the total amount of water you have in the solution that with a 1,5g casein content it results in about 4% concentration. No more water must be added, all water is distilled water.
@@DavideSoraI can't thank you enough. I really appreciate that I can learn a lot from you. God bless you! Buona Giornata!
Grazie Maestro !! I saw in maestronet a picture of the ground of one of your viola, probably the most beautiful ground I never seen. In this case you used mastic resin for sealing wood, why have you used casein intead of mastic in this instrument? Grazie mille !!
I always use Casein first as a sort of sealer and then Mastic in turpentine as a sort of refractive ground. I also put some Pumice in the mastic (up to 20%) as a filler for the pores. It doesn't close them completely but it helps. The color of the ground you saw on Maestronet is mostly UVA exposure (about 300 hours) improved by the effect of the Casein and Mastic if I remember correctly.
@@DavideSora Thanks a lot for the details and explanation ! I hope that soon I could have the opportunity to see an instrument of yours live, but in the photos they looks extraordinarily beautiful.
@@alejandropinerogomez9326 Thank you!😊
@@DavideSora Hi Maestro Davide. Can you give us the recipe of this Mastic refractive ground and how it is applied? I am an amateur violin maker and your help is invaluable. Thanks in advance.
@@mesimerisnikos
If you had read the comments below you would have already found the answer. Anyway, I'll copy and paste it below for your convenience:
The Mastic solution is basically a refractive ground, and is prepared simply by dissolving the resin in turpentine essence, with a concentration of 16% by weight (16% mastic - 84% turpentine).
I also add some pumice to act as a pore filler, but this can be omitted. It is applied with a brush and immediately afterwards the excess is removed with a rag soaked in alcohol, so that it does not form a glossy surface layer but remains only inside the surface. At least 12 hours in the UV lamp will be needed to let it dry (even 24 hours, depending on the type and power of the lamps), otherwise it is better to wait up to a week without a UV lamp. Once perfectly dry, you are ready to apply the varnish.
Buonasera Maestro, essendo io solo un appassionato, volevo chiederle come si rende solubile la caseina in acqua, grazie.
Per solubilizzare la caseina in acqua è necessario utilizzare una sostanza alcalina, le più utilizzate sono la calce (idrossido di calcio) e l'ammoniaca. Una volta sciolta con queste sostanze basiche la caseina si trasforma nei rispettivi caseinati di calcio e di ammonio. Io le utilizzo entrambe, ma ad esempio la colla di caseina utilizzata anticamente era fatta solo con la calce (caseinato di calcio) e in quantità molto maggiore alle dosi che indico nella mia ricetta, formando una pasta densa con un forte potere collante e caratteristiche di irreversibilità a causa della presenza del calcio che la rende resistente all'acqua. Con la sola ammoniaca (caseinato di ammonio) questa caratteristica di resistenza all'acqua è molto minore.
@@DavideSora ... Grazie infinite, Maestro, proverò...
What does the ammonia play the role in this mixture, Davide?
Ammonia is needed to dissolve the casein powder, forming ammonium caseinate, only with water it would not dissolve completely.
@@DavideSora oh~!! Thank you Davide
How did you get that nice wood color? UV-chamber + natrium nitrite, or is it stain? You can see your jar turn brown during the video. Anyways a really good base color I think, very beautiful. Also the gloss of the grain is nice!
The wood color comes from about 200 hours in the UV box, I do not put any other treatment before the application of casein. The gloss comes from wood finishing technique, that is only scraper (no sandpaper) and a light final touch with horsetail (equisetum shave grass and horsehair brush). I don't know why casein becomes dark in the jar, I suspect it is an oxidation due to the presence of ammonia and calcium hydroxide, but I'm not a chemist. Would you have a better idea of what the cause could be? Anyway it stay transparent and contributes somewhat to the final color.
@@DavideSora Thank you very much for sharing! I enjoy your videos a lot. I guess I watched all of them :D. 200 hours of UV sounds a lot, but it looks like you get the most natural color tone this way. Other treatments may be faster, but I guess patience is one of the big players in violin making :). I tried natrium nitrite as an accelerator. It works over night, but the wood gets a note of orange, which I didn't like. I also use scrapers, but didn't try the horse hair brush. I will try! I'm quite at the beginning of my maker career, so I'm very grateful for every bit and piece, that leads me to my inner picture of the perfect violin. Thank you Maestro. All the best from Austria
@@DavideSora I would suppose the color in the casein jar gets browner, because of the small amounts of residue, the sponge removes from your violin while applicating. Even after the horsetail treatment, I guess there will be fine wood shavings, uv-brown in this case.
Yes, I also think that this is the most probable cause of the change in color of the casein that remains in the jar, I think it's also the cause of the slight darkening of the violin after the application, because the wood is left slightly acidified by the UV and reacts with the alkalies present in the casein sealer, which make a sort of neutralization of the ph which I believe is a good thing.
@@DavideSora very nice. thanks for all the great work, and sharing in the field.
I have used Juncus effusus (corkscrew rush) and plan on growing a larger plot of it very soon ;)
Why don't you put the casein in a small bowl while you work so it's easier to soak the sponge? You could always pour back any you'd like to save in the jar afterward...
You're right, but then you have to wash two jars instead of just one..... My fingers are thin enough to fit into the jar.😊
@@DavideSora Ah HA! You are correct! I hate washing dishes too! : )
300 years ago ammonia and calcium hydrochloride was not around as compounds I was wandering if they used urea instead with wood ash .
It is not calcium hydrochloride, but it is calcium hydroxide, which is the common lime that was used long before 1700. At the time of Stradivari, every woodworker used casein mixed with lime to make the glue commonly called cheese glue, making it from cheese or curdled milk and lime. This glue, simply diluted with water or perhaps even with ammonia in the form of animal or even human urine (the purest one was that of children, as written in several ancient manuscripts on painting😊) it may actually be very similar to the one I use, even if it is impossible to know for sure how they made it, as chemical analyzes can confirm the presence of some elements but they will never be able to tell us a recipe, or they cannot detect elements that evaporate without leaving significant traces such as the ammonia. However, there are many different ways to make a casein preparation, as practically any basic substance (alkaline) can dissolve it, including potassium hydroxide (lye made from wood ash) or Borax or many other elements with marked alkalinity
Dear Davide, my questions would be: when you write saturated solution of calcium hydroxide, what would be the % of powder in water, and secondly, as far as I know, casein is not soluble in water, so does it get dissolved in, because of ammonia and lime water, or you use a different one? Meantime, I would thank you so much for sharing your knowledge, and experience with us. We know how many hours you spend for it..! Gracie maestro!!
You are right, Casein is not water-soluble and you need a strong base to dissolve it, ammonia and calcium hydroxide is used for this purpose. You could also use only ammonia or only hydroxide, but in the first case it would be less resistant to humidity and in the second case it would take too much to dissolve the casein and you would get casein glue, which was used by ancient luthiers to glue the central joints of the violin plates and the ribs to the blocks (it's really a water-resistant glue, today it is no longer used because it is a non-reversible glue and would make restoration operations very troublesome).
To make the saturated solution of hydroxide I don't know what the stoichiometric quantity is, simply add excess hydroxide to distilled water until an abundant residue forms on the bottom of the jar and use the clear water above (lime water), check the pH with an indicator and it should give you at least pH 12 (dark blue color on the litmus paper). I don't use pure calcium hydroxide powder but I use real lime, that is Pit lime aged 5 years bought from Kremer : www.kremer-pigmente.com/en/fillers-und-building-materials/limes/529/pit-lime?number=31800
Mi mancavano le sonate del buon Arcangelo in sottofondo
Arcangelico 😇😊