Can you go over poly resin with epoxy resin ? Is there any issues with bonding ?
It is usually better done the other way around if you want a glossy finish…
I have done epoxy lam/fill coat with a poly gloss and it turns out really glossy and nice.
I've been told you can patch polyester with epoxy. I bought a second hand board where that had been done and it wasn't a great job, but it appeared to be watertight. I sold the board before I had to deal with it.
A glossy finish is not a issue. I am going for durability. I like the way epoxy does not shatter as easy a poly . It is a existing poly glass job, but a little weak and light. I am looking to beef up the strengh and weight a little [old school longboard] so i am considering useing epoxy to maximise the results.
Save yourself the headache! Let it go!
The thought of laminating with epoxy over an old board makes me shudder. I hope you’ve read how free of contamination you need to start when using epoxy. Unless you sand off every tiny bit of the existing surface, it will never come clean. And it won’t just be a simple sanding either, because even your sandpaper will spread contamination to your freshly sanded area.
And without more cloth, epoxy won’t add any strength.
Are you hotcoating or repairing? If you’re hotcoating a polyester glassed board stick with polyester resin. If you’re repairing a poly glassed board with epoxy I’ve never had any issues myself. Turn around time tends to be a bit longer though as fast epoxies usually take longer to cure than polyester resin does.
I’ve done a couple on older boards,and they worked just fine. good luck