Thread: MDF and finishes

Ask her what happens to wheat-bix when you put milk on it! Same thing with mfd or chipboard. You are correct, bad idea.

Originally Posted by Ozcee

Is there any finish I could use on MDF that would make it last outside?

Put it in a glass box.

you could encapsulate the MDF sign in 3 to 4 coats of epoxy followed by 2 to 4 coats of a clear 2 pack polyurethane with UV inhibitors.

Depending on the size of the sign, you might be spending in excess of $500 on the protective coating, that is after you have used an autobody filler to smooth the MDF.
Add in your labour and the cost to coat her sign could very easily exceed $1000 by a wide margin.


So yes it's possible to put a superb coating on cheap crap -- it will just cost several times more than the total cost of a quality coating of real wood.

I love MDF. Its the bees knees. Happy to do work for clients in it.

But, an outdoor material it is not.

It won't weetbix. Maybe the old stuff, but modern stuff you can leave outside for years, but it does bend and warp and look horrible fast.

Should be fine if you paint it (all over) with a sealer undercoat then use an outdoor paint on it.