MDF polyester coating

[ozstockman]

Hi guys,

I am new here. Just want to ask a few questions about MDF coating with polyester resin.

I was trying to find someone in Melbourne preferably in Western Suburbs or near Laverton, Hoppers Crossing who can paint/coat MDF sheets for me with two coats, base one in white and top one in clear.

I have asked some guys who do boats but they told me panel beaters can do it. The panel beaters I checked told me that cabinet makers can also do this stuff. I will check with them too but just want to ask you here how much can it cost for 60x90cm MDF sheet to coat it on one side only. I can supply my own MDF, finishing polyester(FGI brand) resin and white pigment. For a start I will need 20 sheets of 6mm thick to be coated(about 10 square meters) but I will very interested in ordering more in 6mm and thicker in the future.

The price that panel beaters gave me seems to be quite high for me.
I have been trying to do it yourself but so far I cannot achieve a nice clean finish.

Also what kind of industry apart from cabinet making and automotive I might need to look at to find someone who can be interested in it. Do painters can do such kind of job or I need to look only for those who can use baking ovens for coating?

Thanks in advance for any help or information that will help me.

[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?

[ozstockman]

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.


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?

[Master Splinter]

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.