Poly laminating resin, sealing top coat?

[fishrdan]

I have a small project of making a couple fiberglass brackets and come to find out, I only have a quart of poly laminating resin. My old gallon of waxed resin was rock hard..... I don't want to go out and buy a quart of waxed resin for the top coat (small project), so can I just seal off the top coat of laminating resin with kitchen plastic wrap, so it cures tack free?

These brackets are not being fiberglassed to anything, they are going to be 100% fiberglass brackets about 8"x8". 4 of them going across the transom of an aluminum boat, to attach the top piece of plywood trim. The brackets do not need to look pretty as they are going to be hidden, I just need them strong as the trim board gets stepped on.

(I know, fiberglass on an aluminum boat... :facepalm::lol

Thanks, fishrdan

 

[Woodonglass]

Re: Poly laminating resin, sealing top coat?

I know you can use PVA on it just like gelcoat just as long as you get it on right when it starts to set up. I suppose it would be the same with plastic but it would have to be a fairly tight fit. Any air that gets to the resin will make it tacky.

 

[fishrdan]

Re: Poly laminating resin, sealing top coat?

I know you can use PVA on it just like gelcoat just as long as you get it on right when it starts to set up. I suppose it would be the same with plastic but it would have to be a fairly tight fit. Any air that gets to the resin will make it tacky.

PVA is what made me think of using the plastic wrap, it's just a barrier to keep air off the resin. I think I can make it air tight, just lay the plastic wrap down like it was another layer of laminate.

I'm guessing the plastic wrap will release OK as I've used aluminum foil as liner with poly resin before, and the foil peeled off the resin just fine.

 

[Woodonglass]

Re: Poly laminating resin, sealing top coat?

Yeah it should release fine

 

[metriccrescentwrench]

Re: Poly laminating resin, sealing top coat?

I've used wax paper before, just gotta take the time to have it make solid contact over the entire surface. It'll release easier than plastic wrap too.

 

[Yacht Dr.]

Re: Poly laminating resin, sealing top coat?

PVA is what made me think of using the plastic wrap, it's just a barrier to keep air off the resin. I think I can make it air tight, just lay the plastic wrap down like it was another layer of laminate.

I'm guessing the plastic wrap will release OK as I've used aluminum foil as liner with poly resin before, and the foil peeled off the resin just fine.

Actually its used to seal/trap the solvents in the resin/gelcoat.

I agree with the wax paper idea instead of plastic wrap. But I guess its up to you.

YD.

 

[ondarvr]

Re: Poly laminating resin, sealing top coat?

Or do nothing, the surface will become tack free on its own after a short time. This is the normal practice in a glass shop.

 

[fishrdan]

Re: Poly laminating resin, sealing top coat?

Actually its used to seal/trap the solvents in the resin/gelcoat.

I agree with the wax paper idea instead of plastic wrap. But I guess its up to you.

YD.

Good info to know, thanks YD!

Or do nothing, the surface will become tack free on its own after a short time. This is the normal practice in a glass shop.

I didn't see your post ondarvr, but thanks for the reply. That's what I found when I mixed up a small batch (cap full of resin and a drop of MEKP) to see if the resin was OK. The test batch wasn't tacky when I checked it the next day. And I was thinking it had something to do with my dry desert environment...

 

[Yacht Dr.]

Re: Poly laminating resin, sealing top coat?

That "stickiness" is a common issue with old school resins. I dont think it happens much any more ( Unless its in the topcoat of gel ).

YD.