I know you hear this a lot, but you deserve to get a message every time it happens: Here I am, with a weird thing I need to duplicate in a material more durable than 3D printing can produce, and I'm reviewing all related videos you've made to be sure I'm approaching it in a manner likely to be successful. I do this every time I need to make a mold of any notable complexity. Thank you so very, very much for sharing your expertise.
I came to this conclusion thankfully when I was younger. Rules are not black/white, however it takes years of experience to know when you can/should break them. So if you're only a few years in to any type of work/craft, should stick to following them for now 😂
I like the critique at the end there, you're not ripping on the other caster, you're just pointing out what you can see and where they could improve. Solid lessons in this one.
@@osmacar5331men are also typically better at hearing criticism, statistically. I know plenty of women who can take criticism, and men who can't, but generally the estrogen balance and how it affects emotion makes criticism very hard to take 😂
@@osmacar5331 no such thing nowadays. Tomboys turned feminist man -haters with blue hair that think they can do anything as good or better than a man can... The last soccer match I actually watched U14 "Cannot be 14 / under teen" boys soccer team embarrassed the U.S womans soccer team 5-2. Imagine what a teenage team of boys would do 🤣
Hello Mister Talone- I just retired out of the Army and I have really just started getting into these arts. Your attention to detail is 2nd to none. Thanks for the instruction!
Once again, Robert, you are a fountain of knowledge! I always thought about the fact that you can pressure pot for tiny details but it never occurred to me to stick the uncured mold with the piece in it back in the vacuum chamber to capture those tiny details. Thanks again for the invaluable wisdom!
Love your videos, Robert! I don’t miss a one! ;) For those looking to do this and would like another approach, here’s what we did. At our industrial urethane casting shop, we would source metal rods for small and/or deep holes and imbed those into the mold. This was especially important when producing a few dozen parts off the same mold.
I never could get that to work for me. It was always fiddly and unreliable. I would love to see how you guys made it work. We use jigs on a drill press and can cycle the parts on and off the machine very rapidly. So for me drilling has been the way to go.
Another fun video, Robert. Glad you relented on your normal procedure with this one, and used a second vac! Definitely the way to go here. I actually do that on probably half the molds I make, avoiding it mostly for parts that would have vulnerabilities, like being hollow, soft, or unknown composition (most stuff I mold is pretty predictable). I even like to use it with clayed-up patterns sometimes, although I generally stop at about half-vac... mainly just to give any unseen bubbles some extra lift. That's just me, of course.
Such an excellent series of videos. It’s just what I needed to refresh my memory on some things. I know I’ll sound old saying this, but I wish the younger generation would stick to doing videos like this that CONTRIBUTE to educating people on SKILLS and not WORTHLESS “in your face” obnoxious stuff that gets views :(
This is the sort of video I wish I had when I started. These methods make the impossible possible. This will be a great resource for folks with complicated holed models. Robert - I have a request for your future videos. I finally got a Foredom wax pen, but I still suck when using it to attach vent sprues. Can you take a few minutes during a future project video and teach us a bit about your technique for applying wax wire vents?
I can cover that in a future vid but the best quick tip is to put a little dot of sticky wax on the model where you want to attach the vent wire. This holds the vent while you build the weld. I usually use sculptors wax to join the wax wire and the model because I have so much more control over it than I do with the blue wire wax. And make sure your heat control on the wax pen is set optimal for welding wax wire.
Great video, always learning something new when I watch you perform your skills. I’ve made on tear mold for a gear on my seed/grass spreader a couple of years and it’s still working great. Now that you’ve showed how to mold/cast a wheel, I can now mold/ cast with confidence some wheels and tires.
That’s a great help, I have a similar problem with an opening on a part which I have been wanting to cast (it’s a bit like a boat deck funnel on a ship).
I love it! Bob you always have at least one or two, maybe a few dozen in your pocket when we think we’ve seen them all. We can always count on you to bring out another great idea when we thought we have seen them all. This wheel of holes proves my point. Nice job! Best regards, Richard
I have actually thought about this method before: the vacuuming with the models still attached and cutting the silicone part that goes through the hole. I thought to myself (as I cannot experiment as I do not own any vacuum or pressure chamber): "Why don't people do this more often?". Now, I am glad that you made this video as it justifies my analysis! With this method and the squish mould method, recasting injection moulded parts in sprue will become much easier!
Wow great! It really is amazing how you can think of something different to cast every week. Your rich experience really shows! Seeing ads on your vids makes me happy knowing you really earn from this thing you love to do. Keep it up our old young man!
I always put my molds into the vacuum chamber a second time after I pour them. I never have to worry about little stray bubbles caught in the rubber and giving me problems later on. The only time I haven't done this was when the part I was casting was hollow and I had to worry about air escaping.
Just found your channel and am enjoying your videos. At 7:17 you say "That seems like a lot of air coming out of those tiny holes." What's happening is that the alcohol in your hardener is reaching vapor pressure. IOW, it's boiling at the lower atmospheric pressure. That can knock a model off its base, and add new bubbles. Lower vacuum can help, but ultimately you're changing the chemistry by boiling off one of the components. If you're using tin cure silicone, this isn't a problem. With platinum cure, it can change the hardness of the rubber.
When pulling air out of a vacuum chamber, it might help to reduce the dead space with a material that wont off gass. That you will have less air to remove from the chamber and can get to your desired vacuum quicker. I also suspect vibration from a sander will help lift bubbles off surfaces and to the top quicker.
For the large tunnel problem at shown about 10:10 I would find a piece of brass rod that fits snug and install that in the object before making a mold. Then I would treat that piece of rod as part of the mold, installing into the mold before each casting. It technically wouldn't be a one piece cut mold anymore though.
I like your pressure/vac chamber you showed near the end of the video. It looks handbuilt. Would you ever consider doing a build video on that? Great content, man.
I did a video about my pressure pots but not a build video. That is because you need an expert welder, ideally one certified in welding pressure vessels, to safely construct these pots. I designed my chambers, but I did not specify the thickness of the steel or do the welding myself because I was not qualified to do so.
The handle on my syrup dispenser broke, I just wanted to know how to make a new handle. I don't have any of these tools so I think buying a new syrup dispenser is what I'll do. Very interesting video though. thank you for sharing.
What a great tutorial, and making ideas spin around in my head. If one could get a stepper motor with a Pi or Arduino that could remotely pour a beaker of silicone inside the vacuum chamber, could that prevent any air being trapped in the mould? I could be just over engineering the process because your cast came out pretty darn good anyway!
I need to make a mold using urethane or epoxy and it will be used to make small parts made of silicone that will have many 1mm diameter holes. Can i use a similar method as this video? Also will the 1mm dia and 3 mm tall pillars casted for holes be strong enough in epoxy or urethane to not break when demolding silicone parts?
Love your videos. You helped me design my first part from scratch out of a combination of clay and two plastic pieces that ground down and manipulated. I have the final part but I cannot design a mold to produce more that doesn't have bubbles problems I am using a pressure potand a squish mold. The resin I am using is a two minute set time and needs the mold to be warm . It is essentially the size of a Nickle but about a 1/4 inch thick. One side has an indented ring on one side and the other has a small cylinder cut out in the middle that goes about 80 percent through with a small hole in the middle that is open to the other side. Any suggestions would be greatly appreciated 🙂 🙏.
I just found this channel and instantly subscribed. This is good stuff, beautifully taught! Just out of curiosity, that wheel looks familiar. Is it by any chance a 1/16 scale Russian tank wheel? Maybe a T/34 or a T/62?
9:52 - If you design the mould so that those long thin pieces of rubber sit _vertically_ while filling / curing, won't that eliminate (or at least reduce) sagging? Of course, it might not always be possible, depending on the shape of the part, but it's something to consider.
Each mold is different so what works for one might not work for another. But even if the rubber doesn’t sag it still has the problem of tearing off after a few casts.
Question about the 2-stage mold. At 5:32, we can see that you've filled 1/2 of the original with rubber with the "cookie" method that you described in the beginning, and it seems to have set. Is that right? And then, you built a box around the original object and poured the rest of the rubber. How does the 1st part (The Cookie part) work with the remaining? Did the two parts bond together? Thanks for your help!
Great video Robert! Are the potential holes in the models the main reason you avoid deairing the mold? I guess it can add more work but I was always assuming that its a good practice to deair as much as possible
Because I cast models from different sources I never know how they are constructed. So I can’t be sure they don’t have hollow voids inside them. I can’t risk putting them under vacuum or pressure. Fortunately, it’s usually not necessary.
You can pretty much make a silicone mold as big as you can afford. But it would not be a good beginner project! Big molds require a lot of planning and effort.
4.58 you can see that the base that you use needs to be metallic, all you need is to heat the bottom of your mold to attach the funnel to the metal and avoid the bubbles.
Hi Robert, I’m really enjoying your videos! I have a very challenging question. I have a medical model of a pelvis and tailbone that I would like to cast. What would be the best approach for this? It’s a very complex shape!!
Plan out the orientation of the part in space so that most bumps point down. This minimizes the number of vents you need. place event at every High Point where the air must escape out the top. Take pictures and plan out your parting line and where you are going to locate the inlet sprue. Ideally the sprue and funnel is strong enough to carry the weight of the model and is sized in proportion to the part so that the resin can fill the cavity rapidly. The funnel will be a great help in attaching the model to the case.
When I watched the older Crafs'man mold failures, no matter what he sprayed on his resin figure to seal it, I started thinking maybe he should try an enamel based spray and forget about those sealers. Any thoughts on that?
You can relax your degassing a LOT. You are not pulling air out of the model at 7:27 you are vacuum stripping volatiles out of your silicone. Some of which need to be in there for the right working properties. A vacuum gauge would let you see how far down you have gotten and then you can hold it at an appropriate level for a few seconds to let the bubbles rise. Rest is just vacuum stripping.
A question as for using vacuum v pressure . . . generally it seems as if you are using vacuum while creating the molds out of the soft rubber materials while you are using pressure to make the castings out of the harder plastics. True, or perhaps with some conditions that apply?
Next week the video is about this exact subject. When to use vacuum and why. And when to use pressure and why. But for a quick answer: I use vacuum to de-air rubber prior to pouring the mold. And I use pressure to suppress foaming in resin when making the casting.
Hi, there is actually an easy and more reliable (and long-lasting) solution to precise deep hoes in silicon molds : rigid rod inserts (steel for example)! - but definitely requires more effort beforehand
@@RobertTolone am I wrong? I'd say metallurgists would, but they'd pit cast them, which is how they where originally made then the rubber was press fit on the rim. That being said, I do wonder how much it'd cost me to have you make a parts kit of some tanks. I'd also enjoy watching vids of you making resin tank models, in 1:15 or 1:25 scale, be a lot easier let me tell you.
i have learnt so much from you´re videos . i watched in one of them that you use vaseline and something else as a mold release , what was the other thing ? have tried by looking in you´re stuff but can´t find it , i thought it would be easier to ask .
Hi Robert. I have a part that has very long through holes and I cannot for the life of me work out a good way to do it. The holes are about 7mm wide and 100mm long. Any ideas?
Pretty much no way to cast it. You just have to drill it. Although there are people who will tell you to use a steel rod in the mold to form the hole in the casting.
@@RobertTolone ow. The metal rod sounds a nice idea. I would drill them but there is also a pattern. It's a complicated part and driving me a little crazy. Thanks for the reply Robert. You are the reason our business has been able to move into resin casting as a production method. You make it look easy and explain the problems along the way. It's helped no end and for weeks already our parts have been shipping to happy customers!
I bought some mold forms like that a Amazon heads up to everyone make sure you confirm the material it's made out of even though it was sold as reusable forms for silicone mold making the forms themselves were made out of silicone....?¿? Why..... 🤯
my rules: use 2 tray, pour one part use vacuum and vibration both on mixed rubber and poured product let it set add departure agent pour the other part clean 2 part mold polish enjoy life
What about a three part mold using metal rods the size of the holes sprayed with release that can slide in for casting and slide out to remove the part when casting long slender through holes? If there are lots of holes you can mount corresponding rods on an external brace to position all holes at once. With this method you can even cast through holes at right angles.
I know you hear this a lot, but you deserve to get a message every time it happens: Here I am, with a weird thing I need to duplicate in a material more durable than 3D printing can produce, and I'm reviewing all related videos you've made to be sure I'm approaching it in a manner likely to be successful. I do this every time I need to make a mold of any notable complexity. Thank you so very, very much for sharing your expertise.
A good artist knows the rules. A master artist knows when to break the rules. You are a master artist. Thanks for another great video.
Thanks for watching!
I came to this conclusion thankfully when I was younger. Rules are not black/white, however it takes years of experience to know when you can/should break them.
So if you're only a few years in to any type of work/craft, should stick to following them for now 😂
I like the critique at the end there, you're not ripping on the other caster, you're just pointing out what you can see and where they could improve. Solid lessons in this one.
They're of a generation that actually knows what criticism is.
@@osmacar5331men are also typically better at hearing criticism, statistically. I know plenty of women who can take criticism, and men who can't, but generally the estrogen balance and how it affects emotion makes criticism very hard to take 😂
@@oldkingcrow777 ahem, tomboys. The only real women
I await your counter argument.
@@osmacar5331 no such thing nowadays. Tomboys turned feminist man -haters with blue hair that think they can do anything as good or better than a man can... The last soccer match I actually watched U14 "Cannot be 14 / under teen" boys soccer team embarrassed the U.S womans soccer team 5-2. Imagine what a teenage team of boys would do 🤣
@@osmacar5331he’s probably not that old
Hello Mister Talone-
I just retired out of the Army and I have really just started getting into these arts.
Your attention to detail is 2nd to none. Thanks for the instruction!
Once again, Robert, you are a fountain of knowledge! I always thought about the fact that you can pressure pot for tiny details but it never occurred to me to stick the uncured mold with the piece in it back in the vacuum chamber to capture those tiny details. Thanks again for the invaluable wisdom!
This channel is 24 carat gold.
Love your videos, Robert! I don’t miss a one! ;) For those looking to do this and would like another approach, here’s what we did. At our industrial urethane casting shop, we would source metal rods for small and/or deep holes and imbed those into the mold. This was especially important when producing a few dozen parts off the same mold.
I never could get that to work for me. It was always fiddly and unreliable. I would love to see how you guys made it work. We use jigs on a drill press and can cycle the parts on and off the machine very rapidly. So for me drilling has been the way to go.
Fantastic video-I have been casting and making jewellery for years and I learned so much from you channel. Thank you Sir.
Holy Casting Rubber Batman! great instructional video as always Robert. You fight bubbles harder than Batman fights crime!
The working title for this video was Holy Molding Batman!
and that's why experience matters ... great content.. Thank You for sharing...
Another fun video, Robert. Glad you relented on your normal procedure with this one, and used a second vac! Definitely the way to go here. I actually do that on probably half the molds I make, avoiding it mostly for parts that would have vulnerabilities, like being hollow, soft, or unknown composition (most stuff I mold is pretty predictable). I even like to use it with clayed-up patterns sometimes, although I generally stop at about half-vac... mainly just to give any unseen bubbles some extra lift. That's just me, of course.
Such an excellent series of videos. It’s just what I needed to refresh my memory on some things. I know I’ll sound old saying this, but I wish the younger generation would stick to doing videos like this that CONTRIBUTE to educating people on SKILLS and not WORTHLESS “in your face” obnoxious stuff that gets views :(
this has always been a huge challenge in my mind thanks for adding some context and explanation that helps
Fantastic video Robert. You answered my second vac questions completely and eloquently as always.
Awesomeness indeed.
This is the sort of video I wish I had when I started. These methods make the impossible possible. This will be a great resource for folks with complicated holed models.
Robert - I have a request for your future videos. I finally got a Foredom wax pen, but I still suck when using it to attach vent sprues. Can you take a few minutes during a future project video and teach us a bit about your technique for applying wax wire vents?
I can cover that in a future vid but the best quick tip is to put a little dot of sticky wax on the model where you want to attach the vent wire. This holds the vent while you build the weld. I usually use sculptors wax to join the wax wire and the model because I have so much more control over it than I do with the blue wire wax. And make sure your heat control on the wax pen is set optimal for welding wax wire.
I love the show of experience and technique differences at the end. Really cool to see the after affects
Great video, always learning something new when I watch you perform your skills. I’ve made on tear mold for a gear on my seed/grass spreader a couple of years and it’s still working great.
Now that you’ve showed how to mold/cast a wheel, I can now mold/ cast with confidence some wheels and tires.
Glad the video is helpful to you!
That’s a great help, I have a similar problem with an opening on a part which I have been wanting to cast (it’s a bit like a boat deck funnel on a ship).
Thank you for your videos, it's basically a one and only detailed casting guide on YT that covers any question you might have.
Beautiful casting !!
Very informative and clear video. Thank you
so many great insights in this one video. glad I found your channel before I start my casting journey. thanks.
I love it! Bob you always have at least one or two, maybe a few dozen in your pocket when we think we’ve seen them all. We can always count on you to bring out another great idea when we thought we have seen them all. This wheel of holes proves my point. Nice job! Best regards, Richard
Something is missing from this video. Mr. Tolone has apparently finally exhausted the world's supply of beeswax. ;)
I’m currently in a rehab program for beeswax withdrawal. It’s hell on earth.
Another great video Robert. You mentioned that it's easy to fix those bubbles, etc. Someday I'd like to see some techniques on how to fix them.
Really enjoyed this one
Fantastic lesson again Master Tolone, so much to learn from you thank you!!
never seen this been made in my life , but it was a interesting video to watch =) thanks!
Another great video Robert! Thanks as always!
Thanks Dan!
I have actually thought about this method before: the vacuuming with the models still attached and cutting the silicone part that goes through the hole. I thought to myself (as I cannot experiment as I do not own any vacuum or pressure chamber): "Why don't people do this more often?". Now, I am glad that you made this video as it justifies my analysis! With this method and the squish mould method, recasting injection moulded parts in sprue will become much easier!
Oooh...that's basically what this accomplishes, isn't it? It's "injection" molds without doing the injection.
@@nekrataali YES EXACTLY! With squish mould, you basically neutralise the pressure inside the mould at the cost of being messy
I JUST LOVE YOUR WORK!!!!
exactly what i needed to see, thankyou
No cliffhanger - phew! I can relax for a few days
Wow great! It really is amazing how you can think of something different to cast every week. Your rich experience really shows! Seeing ads on your vids makes me happy knowing you really earn from this thing you love to do. Keep it up our old young man!
Most of the ideas come from the viewers. Thanks for watching Nathaniel. Also thanks for putting up with the ads.
@@RobertTolone It is really nice that you interact with your viewers. I hope I can send a work of mine to be casted to someday.
always glad to see your vids on moulding u mastered it thanks robert
Mastered it on molds that succeed. The molds that failed, not so much. 😃
Great stuff as usual 👍🏾
I always put my molds into the vacuum chamber a second time after I pour them. I never have to worry about little stray bubbles caught in the rubber and giving me problems later on. The only time I haven't done this was when the part I was casting was hollow and I had to worry about air escaping.
Just found your channel and am enjoying your videos. At 7:17 you say "That seems like a lot of air coming out of those tiny holes." What's happening is that the alcohol in your hardener is reaching vapor pressure. IOW, it's boiling at the lower atmospheric pressure. That can knock a model off its base, and add new bubbles. Lower vacuum can help, but ultimately you're changing the chemistry by boiling off one of the components. If you're using tin cure silicone, this isn't a problem. With platinum cure, it can change the hardness of the rubber.
When pulling air out of a vacuum chamber, it might help to reduce the dead space with a material that wont off gass. That you will have less air to remove from the chamber and can get to your desired vacuum quicker.
I also suspect vibration from a sander will help lift bubbles off surfaces and to the top quicker.
Fascinating stuff as usual Robert. I was sad to hear about your ship model - pain is an unpleasant but effective teacher in those cases!
Not my finest hour! 😭
Nice video. Happy easter, Robert.
Thanks Roger. Same to you!
loved the video !
top work
Very interesting!
Thank you for the real life examples
For the large tunnel problem at shown about 10:10 I would find a piece of brass rod that fits snug and install that in the object before making a mold. Then I would treat that piece of rod as part of the mold, installing into the mold before each casting. It technically wouldn't be a one piece cut mold anymore though.
I like your pressure/vac chamber you showed near the end of the video. It looks handbuilt. Would you ever consider doing a build video on that? Great content, man.
I did a video about my pressure pots but not a build video. That is because you need an expert welder, ideally one certified in welding pressure vessels, to safely construct these pots. I designed my chambers, but I did not specify the thickness of the steel or do the welding myself because I was not qualified to do so.
The handle on my syrup dispenser broke, I just wanted to know how to make a new handle. I don't have any of these tools so I think buying a new syrup dispenser is what I'll do. Very interesting video though. thank you for sharing.
What a great tutorial, and making ideas spin around in my head. If one could get a stepper motor with a Pi or Arduino that could remotely pour a beaker of silicone inside the vacuum chamber, could that prevent any air being trapped in the mould? I could be just over engineering the process because your cast came out pretty darn good anyway!
I always try to keep it as simple as possible. Complexity breeds problems; at least for me.
It’s a road wheel from a Russian t34-85 tank for those who want to know, in what looks like 1/16 scale.
good tip
awesome!!
I need to make a mold using urethane or epoxy and it will be used to make small parts made of silicone that will have many 1mm diameter holes. Can i use a similar method as this video? Also will the 1mm dia and 3 mm tall pillars casted for holes be strong enough in epoxy or urethane to not break when demolding silicone parts?
Love your videos. You helped me design my first part from scratch out of a combination of clay and two plastic pieces that ground down and manipulated. I have the final part but I cannot design a mold to produce more that doesn't have bubbles problems I am using a pressure potand a squish mold. The resin I am using is a two minute set time and needs the mold to be warm . It is essentially the size of a Nickle but about a 1/4 inch thick. One side has an indented ring on one side and the other has a small cylinder cut out in the middle that goes about 80 percent through with a small hole in the middle that is open to the other side. Any suggestions would be greatly appreciated 🙂 🙏.
Could you open pour each side of the mold, let the resin set then squish mold the two halves together?
If I'm creating molds for wax injecting (pressurized wax injecting), do I still need vents, extra channels, or neither? Thanks!!!
I just found this channel and instantly subscribed. This is good stuff, beautifully taught! Just out of curiosity, that wheel looks familiar. Is it by any chance a 1/16 scale Russian tank wheel? Maybe a T/34 or a T/62?
9:52 - If you design the mould so that those long thin pieces of rubber sit _vertically_ while filling / curing, won't that eliminate (or at least reduce) sagging? Of course, it might not always be possible, depending on the shape of the part, but it's something to consider.
Each mold is different so what works for one might not work for another. But even if the rubber doesn’t sag it still has the problem of tearing off after a few casts.
this guy knows how to get the ladies wet!!
A true AMERICAN HERO!!!
Nice . See your work from iraq
Question about the 2-stage mold. At 5:32, we can see that you've filled 1/2 of the original with rubber with the "cookie" method that you described in the beginning, and it seems to have set. Is that right?
And then, you built a box around the original object and poured the rest of the rubber. How does the 1st part (The Cookie part) work with the remaining? Did the two parts bond together? Thanks for your help!
1:30 the time that my satisfaction become real
Great video Robert! Are the potential holes in the models the main reason you avoid deairing the mold? I guess it can add more work but I was always assuming that its a good practice to deair as much as possible
Because I cast models from different sources I never know how they are constructed. So I can’t be sure they don’t have hollow voids inside them. I can’t risk putting them under vacuum or pressure. Fortunately, it’s usually not necessary.
Is that a 1/6 scale Russian t34 -85 wheel looks awesome
everyone on the edge of their seats watching this bubble close up 1:20
What material are you pouring? Is it polyurethane?
I also have a problem with my parting lines being too visible. What is the technique that can make them less apparent?
Wow, those little holes turned out great! How did you handle the few little holes that weren't there in the cast at the end - did you drill them?
Yes, that’s the simplest way.
Could a silicone mold be made from a car bumper or is it too big? Thanks SO much for your videos!
You can pretty much make a silicone mold as big as you can afford. But it would not be a good beginner project! Big molds require a lot of planning and effort.
4.58 you can see that the base that you use needs to be metallic, all you need is to heat the bottom of your mold to attach the funnel to the metal and avoid the bubbles.
Metal makes me nervous around silicone rubber unless I have tested it for cure inhibition. Otherwise your technique could work well.
Great video. Anyone know what brand of rubber he’s using, or can recommend something good like it? I’m new to this and learning a lot still.
Econosil-25 from www.silpak.com
Ciao ma cosa è quello strumento di acciaio con il coperchio dove metti lo stampo? E come funziona?
Hi Robert, I’m really enjoying your videos! I have a very challenging question. I have a medical model of a pelvis and tailbone that I would like to cast. What would be the best approach for this? It’s a very complex shape!!
Plan out the orientation of the part in space so that most bumps point down. This minimizes the number of vents you need. place event at every High Point where the air must escape out the top. Take pictures and plan out your parting line and where you are going to locate the inlet sprue. Ideally the sprue and funnel is strong enough to carry the weight of the model and is sized in proportion to the part so that the resin can fill the cavity rapidly. The funnel will be a great help in attaching the model to the case.
When I watched the older Crafs'man mold failures, no matter what he sprayed on his resin figure to seal it, I started thinking maybe he should try an enamel based spray and forget about those sealers. Any thoughts on that?
You can relax your degassing a LOT. You are not pulling air out of the model at 7:27 you are vacuum stripping volatiles out of your silicone. Some of which need to be in there for the right working properties. A vacuum gauge would let you see how far down you have gotten and then you can hold it at an appropriate level for a few seconds to let the bubbles rise. Rest is just vacuum stripping.
4:37 but it's the proper way) both making a mold and pouring a polyurethane under vacuum is almost an industrial standard.
Could you paint rubber into the small holes before pouring the rest of the rubber?
They were so tiny and there were so many of them that I deemed it easier to vac out the air.
Looks like T-34 tank wheel
Have you given any thought to doing keyboard keycaps? It's a pretty popular thing these days, would like to see your take.
Yes, I’ve been thinking of doing keycaps. Should be fun!
A question as for using vacuum v pressure . . . generally it seems as if you are using vacuum while creating the molds out of the soft rubber materials while you are using pressure to make the castings out of the harder plastics. True, or perhaps with some conditions that apply?
Next week the video is about this exact subject. When to use vacuum and why. And when to use pressure and why. But for a quick answer:
I use vacuum to de-air rubber prior to pouring the mold. And I use pressure to suppress foaming in resin when making the casting.
What are you doing with all the witness cups ?
They go off to witness cup heaven.
Hi, there is actually an easy and more reliable (and long-lasting) solution to precise deep hoes in silicon molds : rigid rod inserts (steel for example)! - but definitely requires more effort beforehand
The T-34 front and rear road wheel, how to make anyone hate you in machining, moulding and resin casting.
😄
@@RobertTolone am I wrong? I'd say metallurgists would, but they'd pit cast them, which is how they where originally made then the rubber was press fit on the rim.
That being said, I do wonder how much it'd cost me to have you make a parts kit of some tanks. I'd also enjoy watching vids of you making resin tank models, in 1:15 or 1:25 scale, be a lot easier let me tell you.
How do we contact you about a mold?
i have learnt so much from you´re videos . i watched in one of them that you use vaseline and something else as a mold release , what was the other thing ? have tried by looking in you´re stuff but can´t find it , i thought it would be easier to ask .
Might have been MR-150 spray release from www.silpak.com.
I’ll check that out , thank you
I think those are drain holes for a SLA printer
how about tin mold making, or tin object casting
tin mold can be hot wire cut half, or just parting line paper separated or two part casted around the particle
Hi Robert. I have a part that has very long through holes and I cannot for the life of me work out a good way to do it. The holes are about 7mm wide and 100mm long. Any ideas?
Pretty much no way to cast it. You just have to drill it. Although there are people who will tell you to use a steel rod in the mold to form the hole in the casting.
@@RobertTolone ow. The metal rod sounds a nice idea. I would drill them but there is also a pattern. It's a complicated part and driving me a little crazy. Thanks for the reply Robert. You are the reason our business has been able to move into resin casting as a production method. You make it look easy and explain the problems along the way. It's helped no end and for weeks already our parts have been shipping to happy customers!
Have you ever used talcum powder to eliminate air bubbles?
Yes, it never worked for me.
You know, the two vents might also mean that the original casting was done on a tree rather than a single piece there.
How did you clean it up? That looks way different from what you poured
You mean parting lines,etc?
@@RobertTolone You know, I rewatched this video and have I no idea what I was talking about 😂
Why not pour each half separately and avoid cutting at all?
Is it a bit weird that I looked at the first shot of the part I recognized it as a late production road wheel from a T-34?
I never asked what the wheel was from but you’re correct, it’s a tank wheel.
I bought some mold forms like that a Amazon heads up to everyone make sure you confirm the material it's made out of even though it was sold as reusable forms for silicone mold making the forms themselves were made out of silicone....?¿? Why..... 🤯
Somebody is making a soviet tank
You don't use a rigid tool to fill those holes? ^_^
It won’t work but it’s worth a try 🤪
@@RobertTolone does the definition of insanity apply here? I mean, repetition of attempt despite lack of success?
Holes? I thought this was going somewhere else.
my rules:
use 2 tray,
pour one part
use vacuum and vibration both on mixed rubber and poured product
let it set
add departure agent
pour the other part
clean 2 part mold
polish
enjoy life
What about a three part mold using metal rods the size of the holes sprayed with release that can slide in for casting and slide out to remove the part when casting long slender through holes? If there are lots of holes you can mount corresponding rods on an external brace to position all holes at once. With this method you can even cast through holes at right angles.