How thick is Reface? Would it cover OSB if applied by roller? I would sand the OSB first with P80 but it would be a quick run over rather than big attempt at flatting.
What are you using it for? Its primarily intended as a mould surfacer, I have used quite a bit of it over the years but for GRP work its white colour is a bit of a pain, more difficult to see imperfections. It also has its own special catalyst & wont work if you use standard Mek peroxide.
A far better mould surfacer is Durabuild, uses standard catalyst & sprays well if you need to, its dark grey colour is great & it cures far quicker than Upol. Only downside is its shelf life is relatively short a once opened tin will go a year at most.
It's going to absorb quite badly into any processed wood type and probably not adhere too well. Might just work if you seal it with epoxy primer. I've primed MDF before and it's held out. Unless you're going to bake your reface, you're probably looking at 48hrs curing. I spray it on with a 2.5 conventional gravity and can probably get 3mm thickness with 2 coats but whilst you won't get so much build, can't see why you can't roller it on.
Nick
3mm with two coats is great, way more than I need. I'll give it a go with the roller then.
As it's cold at the moment I will run a fan or convection heater and I'm thinking of getting an IR bulb or two.