Poly Over Exterior Semi-Trans. Stain?

[Danidog]

I have an oil based semi-transparent stain on my TTT siding. Would it be a good idea to seal that with maybe some Helmsman Spar poly for more protection? My paint store guy says "I dunno"

thanks,

Dan

[48Rob]

I use oil based poly over oil based stain all the time.
It has been done for years.

You can put oil, or water based finish over oil stain.
What you don't want to do is put oil over water based.
Oil dries hard and does not stretch.
Water based/latex stretches/moves, hard non stretch oil over soft stretchy latex will fail.

As to your question about "should I protect it" yes, it would be a good idea as stain does not seal the wood from moisture damage.

Rob

PS. You need to get a new paint store guy that has a clue.
Paint stores sell products that are designed to seal and protect multiple surfaces, inside and out.
If he can't answer that simple question, he isn't to be trusted to give advice on what kind of paint his customers need.

[Danidog]

Thanks Rob.

This is the first BM paint store I've seen where the owner's family doesn't seem to care.

[Tom Kurth]

A long-time interior finish guy told me you could put poly a lot of stuff but make sure it doesn't have stearates in it. That's the stuff they add to sanding sealers so they don't gum up your sandpaper.

Best,
Tom

[mrwall1]

Poly would be a good choice... I am surprised B.M. didn't know.... they sell a really good Acrylic Poly... Benwood Stays Clear.....