Polyester resin thinner?

[DaveR]

What can I use to thin polyester resin so it'll soak into wood a little deeper?

Thanks!

[Liqui-Fly]

Styrene is the thinner of choice. Warm your surfaces too this will allow the resin to penetrate further by lowering its viscosity.
David

[Laker]

Use plastic cups and carefully measure how you mix... Then time it to find out how long it takes to cure in you temp and humidity. If you want it to soak in well you need to mix the resen for a long cure.
If you can, mix it for several hours and then warm the shop up (about 6 hours) and it will fully harden.
Thanks
Chris

[Techno]

You can buy 'git rot' or something similar. its water thin.

Better if you want it to protect the wood, skip the poly and use epoxy.

None of it is really going to soak in. It will only bond to the shallow surface of the wood. If your talking about end grain then it will penetrate quite deep but it sounds like your just coating the sides of the wood and it won't.

[DaveR]

Thanks. I know the epoxy resin is stronger and water resistant, but I'm fresh out. If this piece gets wet, the boat is under water, and I don't plan on that!

What percent styrene can I add and still have it harden? or does it just evaporate and not affect the cure?

[AlaskaStreamin]

10% is as far as you will want to go.

Don't under catylize it to slow the dry time. You can cool down the resin or get a slow cure catylist.

I don't remember the exact measurements but there is a min and max catylist/resin ratio to achieve full molecular activation.

[DaveR]

Thanks guys - I'm on it.

[Arizona Hotboater]

Fiberglass polyester resin is soluble in acetone. I used to thin the resin with acetone and spray it through a touchup gun to lay a fine layer on surf boards.

I have never used styrene but I know that Ron Pratt knows his fiberglass and I trust his opinion. Also, Liquifly is a chemist and should know if styrene will work. The thing with acetone is that you can mix as much as you like with activated polyester resin. You can make it as thin as water. It will soak into un-treated wood.

Good luck,

AZH

[Laker]

Ron is correct… I should clarify.
The temps I refer to for the shop working temp is lower 60sF… This is my reference because of working in the spring and fall here in wisconsin. I mix the resin to cure slowly (about 3-4 hours) and then warm the shop up after that to get a hard solid cure. If the starting ambient temp is too warm the Resin will never cure correctly. Epoxy is far superior in all respects and works wonderful at a slow cure and is my only choice for hulls that I wish to last.:cool: :)

[Superdave]

I use acetone to thin down gelcoat to use in a siphon spray gun. I use the acetone to thin it when spraying metalflake. I believe it was 25% acetone. This works for colors & metalflakes, but not for the clear topcoat. I mixed in some stuff called Patch-Aid to mix with the clear, NO ACETONE here. The Patch-Aid has a wax in it that rises to the top for a smoother finish. Don't be fooled though. A sander with 220 wet/dry is only the start. Clear gel dries VERY rough. I didn't think a siphon gun would spray it, but I went to Hydra-Sports before they closed and was shown buy one of their expert patchers. I've only done it once, but it turned out great. Lots of work! When the gelcoat dries it is about as smooth as a fiberglass boat covered with blisters.