Hi, I've screwed up!! I have used 3 coats of PVA on my new shed, thinking that it would provide a "belt n braces" sealant for the shed. The shed is pre-treated with PROTEK wood stain and protector (Gold). When it rains the whole external woodwork (t&g) turns white, ie the same colour when it was painted on. ? When it dries, the woodwork returns to its original gold colour. Question?: when the shed returns to its original colour (ie no white drips etc) what preservative/treatment can I paint on to stop the "whitening" happening again? I have some NO NONSENSE wood treatment (clear). Thanks for any advice.
Gawd, that is a bit of a screw up, I have no idea what can be put on PVA. You might try white spirit, or pressure washing it.
The PVA will wash off with the rain and frost over winter. You will know when it's all off as the shed won't go white when it rains.
PVA is not a wood sealer, you may try removing it in it's damp state with a pressure washer. It may be possible to paint over the PVA with Bedec Barn Paint as this is a waterbourne product but my advice would be to contact the Bedec paint technical department (Google Bedec for contact info) for accurate advise on it's adhesion qualities when applied over a PVA base.
missed point! the "sealants", that are meant to be in such circumstances are "breathing ones", hence they stay on for way longer than any paint (not "breathing") and moisture (heat-cold- damp) causes paint to peel of, even with primer. Same principal, as in old facia's and soffits. Indeed, pressure washing now, let it truly dry out, then (ideally) sanding and only then, in accordance to instructions, use ONE coat once a year.
Wait until it's as wet as wet can be, ideally constantly wet over a few days so it's very soft and white, and pressure-wash it off as mentioned by Astra. That will also nicely remove the top layer of any preservative... When it's then as dry and dry can be, brush/spray it with Everbuild Lumberjack clear preservative and allow to dry. Then add something sensible...
Sis moved in to a hoosie last year which had green algae-encrusted fence panels. I recommended Lumberjack to try and make them last a bit longer, but didn't expect the transformation in appearance - the algae disappeared and the wood took on a beautiful clean silver hue.
I do feel sorry for OP,but I wouldn't thought anybody would ever use PVA for preserving a shed,never of it being done before.
m8, just kidding honestly this sort of "sealant" misunderstanding is one of the harder one's to put right
Nah, no excuse You need to reduce it to below 2MP. Or cut the shed in half. (Actually, don't post a pic, 'cos the image in my head can't possibly be beat. Especially after IIR's 'fly' comment...)