Thread: MDF polyester coating

Polyester resin doesn't stick well to timber, for a start - you'd be better off using epoxy.

And boatbuilders should be able to give you a price to coat with either polyester or epoxy resin, as it is pretty much one of their standard finishes for boats.

What you have probably been talking about with cabinet makers/auto painters is a two-pack isocyanate, which is different again to poly/epoxy.

What sort of finish are you after? Waterproof? Or just high gloss?

Thanks for your reply. I need it to be able to do sublimation printing. It's done by printing with special inks on a special paper and then using a heat press to sublimate it into polyester coating. It only works very good on polyester.
I have done it on polyurethane coating but there is a lot of problems like colours are not so bright, images are getting frosted after sublimation, plus paper with prints is sticking to polyurethane and I had to wash it out.

With run tests I have done on polyester coating I don't have all these problems. And that's how all comercial products are done, I just need to find a way to coat it clean and smooth with a white background and top clear coat.


It can be either glossy or matte and it shouldn't be waterproof. It all doesn't really matter to me as long as finish is nice and smooth. I would probably be more interested in matte. If my clients want it to be glossy I can always spray polyurethane on top.


The boat guys I asked said they would not be able to help me because they use gel coat. I am not sure what it's and whether it's made of polyester or not. As I have mentioned above I need it to be polyester based only.

I had problems before with polyester adhering to MDF but it was only with sanding polyester resin that I tried to cure under heat lamp.
However it seems that it can only be peeled off it you heat it to high temperature. After I start using FGI finishing resin and some sun curing agent it hardens quite fast and it seems to adhere to MDF very well now. Especially after it's pressed with an image in a heat press 200 °C.

Since I am making indoor wooden signs of this coated MDF I don't think all this "bonding polyester with timber" should affect my products.

Originally Posted by Master Splinter

Polyester resin doesn't stick well to timber, for a start - you'd be better off using epoxy.

And boatbuilders should be able to give you a price to coat with either polyester or epoxy resin, as it is pretty much one of their standard finishes for boats.

What you have probably been talking about with cabinet makers/auto painters is a two-pack isocyanate, which is different again to poly/epoxy.

What sort of finish are you after? Waterproof? Or just high gloss?

Give FGI a call and ask them what their gelcoats are - they have a range of them - they should have one that is simply polyester resin and a pigment colour, which will give you your white background for printing.