PVA formula change

[Tim Long]

Evercoat recently changed thier PVA mold release agent formula from the original green formula to a new purple one. I am having problems with the new formula, it leaves the gelcoat rough and pitted, whereas the old formula had a better sheeting action that left the finish smooth and glossy.This formula leaves droplets, even from a fine mist sprayer such as pre-val, and the droplets leaves pitts and a dull finish. I thought it may be a reaction to the acetone I use to thin the gelcoat, so I waited 30 minutes for it to evaporate before applying PVA, still same problem.Any idea why they changed it? Can I get the old formula from someone else? Do I need to change thinners?

 

[John Visser]

Huh?

I guess you're in the boatbuilding industry, or boat repair business. This is an unusual question for this forum, but I'm interested in knowing the answer. What do you do, and where? I need some professional gel coat work on my C36.jv

 

[Tom]

green PVA

Try Fiberglass Coatings Web Site

 

[Jim Willis]

Try TAP Plastics or Fiberglass Hawaii

Thse are two sources that should be very up with this info and provide the older PVA if they still have it.For the TEch Guy at TAP, try Conrad@tapplastics.com Also visit this web site they will ship PVA, resins etc throughout continental US.David Collignon at Fiberglass Hawaii (Santa Cruz CA branch) is an expert on all aspects of fiberglass construction, including boat building. You can reach him by phone at 831 476 7464 or by fax at 831 462 4817.Hope this is of some help. Jim Willis

 

[Tim Long]

Huh? answered

My repair of fiberglass sailboats started out of necessity, but I have now restored 4 small boats and sold two. I am now working on a C24 Columbia. Is your C36 a Columbia? PVA mold release agent is used to coat gelcoat paint so it will harden. The wierd thing about gelcoat is that it will not dry if left exposed to air. I use gelcoat for smaller daysailers and racing dinghys to make repairs that look the same as the factory finish. For the columbia, I am painting with Pettit's EASYPOXY. Good stuff.

 

[Tim Long]

I'll try a differnt brand

I gave the Evercoat purple PVA another try, assuming I had to be doing something wrong. I changed thinners from acetone to MEK, let it tack, then sprayed on a very heavy coat of PVA until the droplets formed a sheet coating. When I washed it away, the results were the same:dull gelcoat that needed wet sanding with 220 grit, then 600 grit, then polish. This is way too much work, I will throw this stuff out and try TAP plastics formula. I can't imagine this stuff would work in boat molds when I can't even get decent touch-up results.

 

[Steve Dion]

They also sell gel coat with the PVA in it.

Tim:Some mfg. also sell the gel coat with the PVA in the mixture. You may want to check that out too.