Painting MDF

I had this problem also but after using special MDF primer it was fine.

I usually paint the edges with filler and rub down when dry. The main problem with mdf is that the edges and mouldings are super absorbent and the faces aren't, so the porosity needs to be made more uniform before you apply the colour

I've had no problems at all with both emulsion, and oil eggshell over acrylic primer. You need a LOT of primer on the 'end grain' though. several coats sanded between.

Did you use MDF primer?

Mathew

MDF with oil

Extremely interesting reply! What kind of filler do you use, none of mine look even vaguely 'paintable'?

R.

I think I used acrylic primer - the filler method sounds interesting but it sounds very messy and time consuming for new MDF. I've heard somebody uses wallpaper paste as a sealant but I've not tried it.

Just add a bit more water than usual to Polyfilla. Wipe on with a rag if you prefer

Tried it over the last few days. Works a treat. The filler fills all that graininess on the edges and the bits that I routed. Excellent tip.

Thanks again.

R.

Pleasure

A swift coating with a water based acrylic primer/undercoat has a similar effect.

As indeed does several coats of emulsion.

The real problem with MDF is the cracks that appear between abutting panels.

Tried that - raises too much hairiness.

Oh yes, several coats.... (watches paint dry ;-) Stuart's way is one shot - dries fast - quick rub down and prime. I don't like latex to as an undercoat to oil anyway, and latex gloss - isn't - I want to see my face in it.

True. I find that you just can't abut panels. It's fine for traditional Stile and Rail with Panel construction though. That's the only time I use it where it can be seen. I'd use Tulipwood (American 'Poplar') if I could find a source here in North Cumbria.

R.