Poly bonding to epoxy?

[OhioLowell]

Hello all!

I have become aware of the fact that epoxy sticks to anything but poly will not bond well to epoxy.

I would like to pick the brains at large here and find out of there is anyway to make poly bond to resin well?

Thanks in advance!
Lowell

 

[Bondo]

Re: Poly bonding to epoxy?

With a Very Course Sanding,.......

It'll stick,........

But Not Well,..... nor for very Long.......

I have become aware of the fact that epoxy sticks to anything but poly will not bond well to epoxy.

What, Exactly about this needs further Explaining,..??..??...

 

[ondarvr]

Re: Poly bonding to epoxy?

I've tried it a few times to see if I could get a bond I was happy with, I never could. You can find websites that claim to make it work, but I've called them to asked them directly about it and they start to back down on the claims and say it may not be the best way to use these products. If you start with epoxy stay with it.

 

[Boomyal]

Re: Poly bonding to epoxy?

I've tried it a few times to see if I could get a bond I was happy with, I never could. You can find websites that claim to make it work, but I've called them to asked them directly about it and they start to back down on the claims and say it may not be the best way to use these products. If you start with epoxy stay with it.

ondarvr, funny this should pop up. I was going to ask about retro gel coat spray over epoxy parts on polyester structures.

I'm starting to think about how to re-do the deck and doghouse on my Beachcraft. The doghouse has the epoxy drink holder on it and the deck has various holes patched with epoxy.

For the price of good 2 part marine paints and primers, I thought I might get a better finish with spray on gelcoat. I want to do a light color and any paint I've ever had experience with seems to take weather stains. Gelcoat seems to stay better looking longer.

What's your take?

Sorry for the hijack OL. I should have started another post.

 

[ondarvr]

Re: Poly bonding to epoxy?

Boomyal

Post applied gel coat normally stains much easier than good paints do, especially after the gel coat has been sanded and buffed to get get a good surface. It's usually thick enough to to buff and remove the stained surface a few times so it can be made to look again though

When gel coats are sprayed onto a mold, there is a very thin resin rich layer at the mold surface, this layer protects the fillers and pigments from the weather and can be very glossy. When that resin rich surface is sanded off it exposes those fillers and pigments to the weather and all the stuff that may land on it. Sometimes oils, dirt and other things can easily be absorbed by that surface.
When gel coat is post applied that resin rich layer is not protecting the surface, and even if was there to start with, it would be sanded off in the process of getting a smooth surface.

Gel coat will sort of stick to epoxy if the surface is sanded very well. It will stay in place until it gets banged or stressed, then it will just pop off, after the first spot pops off it will continue to peel away easily.

 

[Boomyal]

Re: Poly bonding to epoxy?

Well, I guess that simplifies that. Back to looking at a good 2 part paint. Thanks

 

[A Fn Noob]

Re: Poly bonding to epoxy?



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