Painting OSB

[Munroast]

Does OSB have a wax finish ? what would be the best way to remove this before painting? would rubbing it down with white spirit do the trick


Just going to finish it with black bitumen, do I bother with a primer, or just slap it on.

 

[foxhole]

Osb has no “finish”.

 

[Munroast]

apparently the way it is compressed during manufacturer can leave quite a lot of wax on the surface. I have never tried painting it before so wondered how others may have got on.

Also what is best way to seal sawn edges ?

 

[scbk]

I've never done any prep/priming, just slap the paint on, and away you go.

 

[Deleted member 174758]

It's whatever they use as a release compound for the press, so oil or wax. The edges need filling, so maybe drywall jointing compound or PVA glue and sawdust?

 

[opps]

It's whatever they use as a release compound for the press, so oil or wax. The edges need filling, so maybe drywall jointing co.pound or PVA glue and sawdust?

Powder based finishes on edges eventually blow. When I first started decorating, I used to feather out imperfections in timber with Tetrion powdered filler (t the time I was and sanding). I recall going back to a job after 5 years. I could see every point that I had previously filled.

Even 2K fillers will push out in time but the paint doesn't blow. I now only use the powdered fillers on plasterwork.

 

[Deleted member 174758]

I must admit that with the material being OSB I was only thinking of it being in use in the short term (say 1 to 2 years, although admittedly I didn"t ask), and for that I thought the potentially large volume of 2K needed combined with the price of 2K would be prohibitively expensive

 

[Munroast]

Indeed, what is it for;
It is to replace the top of my wood (firewood) store, the last bit was a bit of that green chipboard 22mm flooring that had one coat of bitumen, amazingly it lasted 18 years (its been sodden and out of shape for the past 3)

I have a bit of free 18mm OSB, that is to replace it with. just looking for some cost effective way of finishing so as I get another 18 years, have plenty free Bitumen (so it can have 3 coats of that), but the edges always seem to be the achillies heel of this stuff so whats best for that, have plenty half tins of varnish and oil based wood primer kicking about, either of them any good to soak into the end grain before the black stuff gets slapped on.

 

[opps]

Given your usage, I would probably go with either oil based varnish or oil based primer and not worry about any fillers. Just make sure that you push the bitumen in to the gaps.