That was generous of you to share your knowledge for free…. I don’t have a boat and I’m not making a repair ha but I’m smarter today than I was yesterday. Cheers
Thanks for another great video. No matter how many of your videos I watch i still say the ending with you daughter and always smile. It reminds me of all the time I lost with my kids when they were little. Now im loosing all that same time with my grand kids
Thanks, great video. Clearly explained why not to use waxed gel coat. I have been sealing sprayed gelcoat with any brand of Mega Hold Hair Spray. Same key ingredient as PVA. But way cheaper and already in a spray can. Works great. Wash off with warm water. Just let the gelcoat sit for a couple of hours to be sure all solvents have evaporated before spraying Mega Hold. Credit to some article in Epoxyworks Magazine for the idea.
Cool video, thank you for posting. Over the years, I have used (got suckered is more accurate) into using the latest greatest alternative gel coats. I have found if it matrers, there is really only one answer, and that is the real (traditional) thing.
Having worked in a yard my whole career the Preval was the primary sprayer for small areas. The MOST frustrating thing was the inconsistency of each unit. You can pretty much get a system going where you can mix the gelcoat consistently to get good results but the sprayers drove me crazy. We would but at least 1 case maybe more at a time & if your in a cycle of doing a lot of sprayers it's ok. But buy a case, use a few then let the others sit for a few weeks, grab 1 & start using it & the propellent has leached out so it's useful for 20 seconds & dies. Now you have to scramble around because you only have so much time with the mix.
How long have you worked on boats for? Prevals work if you know how to use them. If the gel is thin and preval has gas still and is not cold, It has to be the small hole that’s clogged up at the bottom where you insert the plastic straw. A lot of times the hole is really small which causes it to spray like crap . Get a thin metal pin and make it bigger. Make sure to also clean it thoroughly with acetone inside and out
Try wrapping a hot wet rag around the Preval sprayer. It will help keep the temp up and make the cartridge last longer. Works for rattle cans too: a bucket of warm water (not hot!) will give them a boost when they’re cold.
I use these pre-valves often and one thing you can do is keep a heat gun handy and keep them warmed up as you go I just pop them off the top and warm them for about 15 to 30 seconds then resume
Hey Andy. Have you done a video on drilling a transom for an outboard with over size holes, filling the holes with epoxy then redrilling to the proper size?
Just realized I've missed two months of your videos. Checked and Yup, I was still subscribed. HOWEVER, YT changed the notification bell from "All" to "Personalized."
Keith Rucker over at VintageMachinery used one of those to paint some old Cast Iron Norton Tri-Stone holders....he said he most likely wouldn't use them again. The things constantly froze up, and did exactly what you said...and that was enamel paint that was properly thinned. He said he'd pull a sprayer out to do it next time.
how good is physics, colder the temp the less pressure you get out the nozzle, plus this vid convinced me that 2 pac is the way to go, just prep a bigger area and blend it
Tried Preval with variety of house paints and it clogged due to freezing of the outlet. Pressure drops and it freezes quick. I tried it in Florida and maybe paired with the humidity it was worse at freezing. 🤷♂️ Absolutely worthless. Maybe could work with thin stains. I can’t imagine using it with gelcoat.
I repair leather seats and I use these when I need texture to hide a repair to reproduce the grain pattern in a door or seat or armrest, they simply spit to much. I would recommend a badger. 250-4 with large nozzle.
Could you apply a layer(or multiple layers over 1 or more spray sessions) of laminating resin w/o wax and then final layer with the resin w/wax so the whole thing will cure hard? Re-coat time interval for all layers could be multiple sessions over multiple days. I am assuming that the requirements would be the same as using laminating resin when laying up glass, do not require sanding between layers(if done in a reasonable amount of time of course), is that correct?
One question I have about above vs below the waterline.. regarding gelcoat, fillers, paints etc.... is this only for boats that live in the water or also for trailered boats that live most their life's out of water?
Video suggestion: a re-visit: "teak" decks. Fake teak/eva/foam.. maybe theres even some good and cheap alternatives? Id like to try spruce wood, oiled with color that makes it look a bit like teak. Good idea or not? Thanks for a great video knowledge source for all my boat projects!!!
The propellant is a mixture of butane and propane so be sure to have no open flame when using a Preval sprayer. Link for the MSDS - preval.com/wp-content/uploads/2018/10/Preval-Spray-Gun-Power-Unit-SDS-ENGLISH.pdf I have found that Preval sprayers work very well for small jobs, but the viscosity of what you are spraying is critical. I have sprayed water based finishes with Prevals and you really have to pay attention to the spray unit temperature there too. The only other downside of Preval sprayers is that they are expensive, but for a small job you may spend almost as much on solvents cleaning out a regular spray gun.
Andy ....I want to reapply gel coat on my boat with a dump gun ....how much gel coat do I need .....how much coverage does a gallon do and at what thickness do I need ....please help.....
With any product, there should be a 'material safety data sheet' so for that sprayer just search for 'Preval sprayer MSDS' and you have the answer ;) I used to have a spraycan that was refillable, but you pressurisde it with a standard air compressor or tyre pump (search for 'refillabble spray can' you should be able to find what looks like a normal aerosol can, but with a tyre valve
Harbor freight little touchup gun drill the tip ( can't remember the exact size i can check if your interested) spray two coats not thinned then sand to 100, then take your good gun thin to 17seconds on a Zahn #4 cup spray looks like glass...I like styrene too but has a short self life. oops! thats a ford #4, hey I bought it like thirty years ago.
I Work at a boat shop in Northern lower Michigan. Been seeing Centurian/ Grady Whites with hull blisters lately. New boats If you could have a video covering this would be great. Repair blistered as well..😬
Centurian says from the factory only Up to 2 weeks in the water or voids warranty.. How do you repair something like this? Is there something going on with EPA and restrictions on resins??
Andy I'm apply same sprayer -garbage only I just spoiled a portion of the gelcoat ,,, there is a liquid in it that probably just interferes with the normal spraying of the material, it may be necessary to heat the balloon to a certain temperature before use, but it does not work correctly, as shown in the advertisement in general
Just out of curiosity what size nozzle do they have? I tried a compressor and spray gun with 2mm needle/ nozzle and it was spitting quite a bit even with a 2% styrene added to thin it out.
I honestly don't know what size nozzle Preval has, but it's pretty small. If I were spraying gel with a regular gun and compressor I'd be reaching for something 1.5mm - 2mm
Hi, I have got questions. How do you stop the leaks in the air vent? Do I need to remove the filter from the tube when I spray 2k primer, 2k clear coats and base coats? Can I refill 2k primer and 2k clear coats and reuse it again?
Damm I used the durateck on the bottom of my 1972 boston whaler will it blister on a trailer boat? I've had a problem micro cracks appearing after filling yes it has the boston whaler alligator pox on gel coat I have used the 3m vinylester filler. the latest try is to soak the surface with west epoxy with slow hardener it been on a test area 3 months so far its ok should i use hibuild epoxy primer im finishing the topsides with paint. will paint on the bottom stave off the blisters I hate to flip it over again thanks jerry k
Hey, I have a 26ft I want to spray(first time). I have 5gallons of waxed gelcoat. Should I spray one side of the boat at a time to get as much build up or should I try to go around the boat a few times before it kicks? What advice do you have?
I just googled styrene: apparently bad stuff. I love those little sprayers. When I was da fix-it guy for 126 new homes I carried them with all the colors needed to touch-up after doing spot-repairs in drywall, trim and cabinetry. When sprayed for only a few seconds the cooling problem doesn't exist.
But you really need a gellcoat gun with a 2.5 mm. nozzle or a metal flake nozzle on a car spray gun, remember you want a GELL coat, not a thin paint-like finish... Only the Mono Styrene, if you don't have the wax gellcoat you can add melted paraffin wax to the styrene first. I make my own gellcoat from polly resin add pigment then add the melted wax to the styrene in the correct ratio and go from there. Not easy to get right the first time.If you really want to mix using the chemicals not the fancy costly additives learn by experimentation. This is better because then you will become a chemist and know WTH you are doing.😀
That was generous of you to share your knowledge for free…. I don’t have a boat and I’m not making a repair ha but I’m smarter today than I was yesterday. Cheers
Thanks for another great video. No matter how many of your videos I watch i still say the ending with you daughter and always smile. It reminds me of all the time I lost with my kids when they were little. Now im loosing all that same time with my grand kids
Thanks for showing this very informative. Another idea to demo would be the $10 Harbour freight paint sprayers. Always wondered if they would work.
That is exactly what I was going to ask will the cheap harbor frieght sprayer spray it?
Me too
I don't know why a HF sprayer would not work, but I would advise going for a larger aperature spray tip rather than the stock one.
Thanks, great video. Clearly explained why not to use waxed gel coat. I have been sealing sprayed gelcoat with any brand of Mega Hold Hair Spray. Same key ingredient as PVA. But way cheaper and already in a spray can. Works great. Wash off with warm water. Just let the gelcoat sit for a couple of hours to be sure all solvents have evaporated before spraying Mega Hold. Credit to some article in Epoxyworks Magazine for the idea.
Great advice, learn so much on this channel.
Andy, thanks for this video. Maybe do one on some of the rattle can that come with the hardener, that you mix in then shake and spray.
i dont use them but ive always been curious about these things. thank you for doing this.
Cool video, thank you for posting. Over the years, I have used (got suckered is more accurate) into using the latest greatest alternative gel coats. I have found if it matrers, there is really only one answer, and that is the real (traditional) thing.
Having worked in a yard my whole career the Preval was the primary sprayer for small areas. The MOST frustrating thing was the inconsistency of each unit. You can pretty much get a system going where you can mix the gelcoat consistently to get good results but the sprayers drove me crazy. We would but at least 1 case maybe more at a time & if your in a cycle of doing a lot of sprayers it's ok. But buy a case, use a few then let the others sit for a few weeks, grab 1 & start using it & the propellent has leached out so it's useful for 20 seconds & dies. Now you have to scramble around because you only have so much time with the mix.
How long have you worked on boats for? Prevals work if you know how to use them. If the gel is thin and preval has gas still and is not cold, It has to be the small hole that’s clogged up at the bottom where you insert the plastic straw. A lot of times the hole is really small which causes it to spray like crap . Get a thin metal pin and make it bigger. Make sure to also clean it thoroughly with acetone inside and out
@@alanc.142p
Try wrapping a hot wet rag around the Preval sprayer. It will help keep the temp up and make the cartridge last longer. Works for rattle cans too: a bucket of warm water (not hot!) will give them a boost when they’re cold.
Now I know why I had no success with those sprayers! Cheers!
I use these pre-valves often and one thing you can do is keep a heat gun handy and keep them warmed up as you go I just pop them off the top and warm them for about 15 to 30 seconds then resume
Hey Andy. Have you done a video on drilling a transom for an outboard with over size holes, filling the holes with epoxy then redrilling to the proper size?
My old spray tan set up from a tanning salon works great for spraying cut gelcoat ( and everything else ive tried to run thru it )
Great job. Thanks for the advice
they work great completely vertical, but are much more difficult to use at weird angles
Just realized I've missed two months of your videos. Checked and Yup, I was still subscribed. HOWEVER, YT changed the notification bell from "All" to "Personalized."
Keith Rucker over at VintageMachinery used one of those to paint some old Cast Iron Norton Tri-Stone holders....he said he most likely wouldn't use them again. The things constantly froze up, and did exactly what you said...and that was enamel paint that was properly thinned. He said he'd pull a sprayer out to do it next time.
how good is physics, colder the temp the less pressure you get out the nozzle, plus this vid convinced me that 2 pac is the way to go, just prep a bigger area and blend it
Perfect as usual.......
Tried Preval with variety of house paints and it clogged due to freezing of the outlet. Pressure drops and it freezes quick. I tried it in Florida and maybe paired with the humidity it was worse at freezing. 🤷♂️ Absolutely worthless. Maybe could work with thin stains. I can’t imagine using it with gelcoat.
Check the MSDS for the propellant contents.
I repair leather seats and I use these when I need texture to hide a repair to reproduce the grain pattern in a door or seat or armrest, they simply spit to much. I would recommend a badger. 250-4 with large nozzle.
I've used these to spray PVA on top of fresh gelcoat. Spray 2-3 coats with 5-10 minute drying time between.
Is the amount of hardener based on volume of gelcoat without cut?
Could you apply a layer(or multiple layers over 1 or more spray sessions) of laminating resin w/o wax and then final layer with the resin w/wax so the whole thing will cure hard? Re-coat time interval for all layers could be multiple sessions over multiple days. I am assuming that the requirements would be the same as using laminating resin when laying up glass, do not require sanding between layers(if done in a reasonable amount of time of course), is that correct?
One question I have about above vs below the waterline.. regarding gelcoat, fillers, paints etc.... is this only for boats that live in the water or also for trailered boats that live most their life's out of water?
The project that blew up on me was a trailered boat. Spent maybe a weekend in the water on a fishing trip and it blistered :-/
@@boatworkstoday guess that answers that definitively 😀 Thanks!!
Video suggestion: a re-visit: "teak" decks. Fake teak/eva/foam.. maybe theres even some good and cheap alternatives? Id like to try spruce wood, oiled with color that makes it look a bit like teak. Good idea or not? Thanks for a great video knowledge source for all my boat projects!!!
Hi Andy. Wouldn't it be easier to use the Gelcoat with the additive you used on the dinghy and roll it out for a small repair. Great video thanks 😊
Just what I thought too
They use either propane or butane as a propellant.
The propellant is a mixture of butane and propane so be sure to have no open flame when using a Preval sprayer. Link for the MSDS - preval.com/wp-content/uploads/2018/10/Preval-Spray-Gun-Power-Unit-SDS-ENGLISH.pdf
I have found that Preval sprayers work very well for small jobs, but the viscosity of what you are spraying is critical. I have sprayed water based finishes with Prevals and you really have to pay attention to the spray unit temperature there too. The only other downside of Preval sprayers is that they are expensive, but for a small job you may spend almost as much on solvents cleaning out a regular spray gun.
Andy ....I want to reapply gel coat on my boat with a dump gun ....how much gel coat do I need .....how much coverage does a gallon do and at what thickness do I need ....please help.....
Great tips and info!
Indeed very helpful!
With any product, there should be a 'material safety data sheet' so for that sprayer just search for 'Preval sprayer MSDS' and you have the answer ;)
I used to have a spraycan that was refillable, but you pressurisde it with a standard air compressor or tyre pump (search for 'refillabble spray can' you should be able to find what looks like a normal aerosol can, but with a tyre valve
Good stuff andy!
Harbor freight little touchup gun drill the tip ( can't remember the exact size i can check if your interested) spray two coats not thinned then sand to 100, then take your good gun thin to 17seconds on a Zahn #4 cup spray looks like glass...I like styrene too but has a short self life.
oops! thats a ford #4, hey I bought it like thirty years ago.
I Work at a boat shop in Northern lower Michigan. Been seeing Centurian/ Grady Whites with hull blisters lately. New boats If you could have a video covering this would be great.
Repair blistered as well..😬
Centurian says from the factory only Up to 2 weeks in the water or voids warranty.. How do you repair something like this? Is there something going on with EPA and restrictions on resins??
Andy I'm apply same sprayer -garbage only I just spoiled a portion of the gelcoat ,,, there is a liquid in it that probably just interferes with the normal spraying of the material, it may be necessary to heat the balloon to a certain temperature before use, but it does not work correctly, as shown in the advertisement in general
I just bought one of these sprayers to try with Awlgrip. Have you tried the Awlgrip yet with this sprayer?
Wow think my boat may have blisters in the gel coat as well I just picked it up not too long ago
Finally!!!! Thank you
Just out of curiosity what size nozzle do they have?
I tried a compressor and spray gun with 2mm needle/ nozzle and it was spitting quite a bit even with a 2% styrene added to thin it out.
I honestly don't know what size nozzle Preval has, but it's pretty small. If I were spraying gel with a regular gun and compressor I'd be reaching for something 1.5mm - 2mm
Hi, I have got questions. How do you stop the leaks in the air vent?
Do I need to remove the filter from the tube when I spray 2k primer, 2k clear coats and base coats?
Can I refill 2k primer and 2k clear coats and reuse it again?
Is there an alternative way to touch up an area about 1 sq foot? Roller? I haven’t used an air brush before. Can you show us these alternatives?
Damm I used the durateck on the bottom of my 1972 boston whaler will it blister on a trailer boat? I've had a problem micro cracks appearing after filling yes it has the boston whaler alligator pox on gel coat I have used the 3m vinylester filler. the latest try is to soak the surface with west epoxy with slow hardener it been on a test area 3 months so far its ok should i use hibuild epoxy primer im finishing the topsides with paint. will paint on the bottom stave off the blisters I hate to flip it over again thanks jerry k
How’s the shoulder holding up, Andy?
pretty sure your dad was willie nelson, thanks for all your videos ive learned a ton
My guess is its dimethyl ether or some other HC like propane
Hey, I have a 26ft I want to spray(first time). I have 5gallons of waxed gelcoat. Should I spray one side of the boat at a time to get as much build up or should I try to go around the boat a few times before it kicks? What advice do you have?
I just googled styrene: apparently bad stuff. I love those little sprayers. When I was da fix-it guy for 126 new homes I carried them with all the colors needed to touch-up after doing spot-repairs in drywall, trim and cabinetry. When sprayed for only a few seconds the cooling problem doesn't exist.
My gelcoat appears to have cracks in it. Can I clear gelcoat over the cracks?
Have you ever used pledge to cover the unwaxed gel coat? I heard it will allow the unwaxed gel coat to cure…
SDS says the propellant is 30-60% propane and 30-60% butane.
I just brushed gel coat on my transom should I add marine paint to protect it ? Did I miss something 😢 hasn’t been in water just yet either 😬
Or is it just when thinned out and sprayed will it blister? 🤔
DAMN!!!! @5:05
Does the gelcoat without wax harden up? Do you have to do something additional to replicate the action of the wax?
Usually I'll let the gel setup for a few hours (or even overnight) then do a light coat of PVA to fully cure things :-)
How about using one of those on that green spot behind you. That unfinished section on that amazingly shiny and dark hull bugs me every week. 😂
Take a look at the 3M Accuspray PPS system. Tips and cup liners are disposable. Preval on steroids!
Your shop temp is 68!? It's 25 degrees outside.
Great video. Fantastic explanations. The added music is untennable, sorry to complain.
And now you understand how AC works lol
Methyl ethyl ketone mek is okay
prolly nitrous in then can LOL party on Andy LOL
But you really need a gellcoat gun with a 2.5 mm. nozzle or a metal flake nozzle on a car spray gun, remember you want a GELL coat, not a thin paint-like finish...
Only the Mono Styrene, if you don't have the wax gellcoat you can add melted paraffin wax to the styrene first. I make my own gellcoat from polly resin add pigment then add the melted wax to the styrene in the correct ratio and go from there. Not easy to get right the first time.If you really want to mix using the chemicals not the fancy costly additives learn by experimentation. This is better because then you will become a chemist and know WTH you are doing.😀
GELCOAT vs boat paint....
But the Moppie? 😭