View Full Version : Small/tight enclosure for curing PolyU finish
Tegmark
17th September 2015, 01:13 AM
When going for an off the brush PolyU canned finish, straight after the final coat I move the work piece which is level the whole time into a makeshift enclosure covered in clean plastic. The enclosure is just slightly bigger than the project & pretty much sealed until its cured. So lite dust won't stick at all. Small volume/space= less dust.
I tried this a few times & it come up pretty good, pristine & clean. But reading about how automotive paint jobs need fresh air around them or the final coat can be flawed which made me start thinking if this can be ruined to? As the evaporating solvents will stay in the enclosure. One enclosure was 50cm sq for a small a4 size flat piece for example.
Just curious what your thoughts on doing this & if anyone has done it?
Thanks
Arron
17th September 2015, 07:03 PM
I haven't tried it because I wouldn't.
It doesn't sound like a good way to finish anything.
I could be wrong here but I presume you are making small items in a commercial or semi-commercial way. If that's the case then the way you are choosing to finish them is hard, slow and profit-destroying. PolyU takes a long time to dry - doing multiple coats is a slow process - and it attracts every piece of dust in the neighbourhood. And the end result is nothing to celebrate anyway.
If you haven't already then investigate industrial lacquers like precat laquers (eg. Wattyl rediseal and stylewood, or mirrortone) or even old fashioned nitrocellulose lacquers. These will give you the same result but much quicker because they dry quickly, sand easily and can be recoated (in some cases) within a few minutes. Most importantly, because they dry so quickly they don't need protection from dust - just spray in your normal environment or outside, and the few dust nibs that do occur will vanish during the buffing process.
Of course you do need to spray - so there is a learning curve involved - but at least you loose the brush marks.
cheers
Arron
Master Splinter
17th September 2015, 09:42 PM
Automotive paints have like a five minute flash off period before the next coat; as for drying it's either hit the bake cycle in the booth after the clearcoat goes on or roll it out the booth to make way for the next job, so I'm not quite sure what fresh air requirements you're thinking of (it's the painter that needs the fresh air in the booth!).
But I find that automotive acrylic clear makes a good wood varnish; hard, clear (without being cool or warm), dry in a few minutes, and easy to touch up.