# Interior plywood painting....Mega sheets!



## KEEGS (Nov 26, 2009)

A good friend and fellow tradesman just finished his "barn" and asked if I would finish the interior for him. There are about..hmm..a Million sheets of plywood (small exageration), with about 5 million knots, inside this "mother of all man-barns". The interior is insulated and climate controlled with radiant floor heating...pretty sweet. He indicated that he wanted all of the plywood painted. I have read previous threads, with quite a few different responses. So, with the details I have provided, I am hoping to give my friend a longlasting, durable, knot-free (bleed), finish. Just some FYI, he understands what we are dealing with here...he isn't expecting miracles. Over the years we have painted a ton of everything...except plywood. My initial thoughts were BIN and obviously a WB topcoat. I just never applied that much BIN to anything of that magnitude before. Any issues with spraying BIN aside from the obvious? Painting plywood...go figure?

Any help is greatly appreciated.


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## venetian designs (Nov 24, 2007)

I don't really have much experience with plywood or how those knots bleed. But I think a safe system would be 2 coats of Cover Stain and a topcoat.


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## TJ Paint (Jun 18, 2009)

Hell, If I was him, I'd just poly all of it and be done.


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## briancreary (Oct 12, 2010)

*wow...but pretty cool*

I kind of like the poly idea..I mean if your friend is going for a finished look then plywood will never achieve this anyway. I once had to go do a touch-up job for a certain company to be unnamed, where their door installer put CDX (aka crap) plywood around their door for a finish, then painted it. Not only do you still see where the knots were even with oil primer, but you also see all the grain, the splinters, the glue lines ect...not a good idea for a finished look. We had to re-cover the previous guys work with finish grade 1/8" plywood, redo all his custom molding, then primer twice with coverstain and finish paint. 

Polyurethane would at least accentuate the knots instead of looking like "hey, I wanted it finish but I'm too cheap to acctually do it right." Other than that, he might have his money better spent just getting some pre-finished wall panel and having you install it, or getting it drywalled (hey you won't have any problem hitting wood behind the board).


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## kdpaint (Aug 14, 2010)

Hmmmnn, Poly sounds good. Some tinted (cover up the cheapo look plywood a little) ZAR ultra max, big lambswool or sprayer, and it is done quick and easy. And, most importantly, ready for immediate man-cave use.


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## fauxlynn (Apr 28, 2011)

Bleed free knots--lacquer


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## StripandCaulk (Dec 30, 2011)

fauxlynn said:


> Bleed free knots--lacquer


unless your talking about wb lacquer..which wouldnt work as hot for blocking bleed. solvent based lacquers, your not going to want to spray that out in a closed building without alottt of ventilation. not to mention the legalities, finish cracking with minimum expansion/contraction of the plywood which will happen. stain and poly might be a cool look, its a barn right? painted plywood looks cheap imo. keeping it a little natural might add a rustic clean feel to the place. i agree with TJ :thumbsup:


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## fauxlynn (Apr 28, 2011)

StripandCaulk said:


> unless your talking about wb lacquer..which wouldnt work as hot for blocking bleed. solvent based lacquers, your not going to want to spray that out in a closed building without alottt of ventilation. not to mention the legalities, finish cracking with minimum expansion/contraction of the plywood which will happen. stain and poly might be a cool look, its a barn right? painted plywood looks cheap imo. keeping it a little natural might add a rustic clean feel to the place. i agree with TJ :thumbsup:




Maybe I was thinking shellac, are shellac and lacquer the same thing (you know the stuff made from the Lac insect) ??? I don't know anything about spraying, but I do know that shellac prevents knots from bleeding.


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## wills fresh coat (Nov 17, 2011)

back in the day when i worked for someone else we did a barn just like this and the ho wanted all the interior painted (3/4 panaling) it was 20 horse stalls and a few rooms, we used one coat of coverstain and two coats of proclassic....wish i had pics it came out great. it was located in potomac md and it had to be the most expensive barn i had ever seen, probably cost around a mill.....:notworthy:


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## Amish Elecvtrician (Jul 3, 2011)

I don't envy you. You have to decide, up front, just how hard you want to work. A lot depends on exactly what your friend wants as a 'finished product.'

At a minimum, he HAS to seal the wood with something, or it will collect grime and look like a grease pit in little time. The plywood will also swell quite a bit as it absorbs moisture. That moisture detail is a problem for painting, too.

So, as a first step: does he want to see wood or wall? If it's wood, it's time to get some satin-finish Spar Varathane and a roller. Maybe dilute the varathane a bit with mineral spirits for better penetration, and follow with a second coat.

If he wants to see 'wall,' I'd first fill the major rough spots with "hot" (powder you mix and it sets fast) joint compound, then seal it all with an oil-based primer. Yes, I know, it seems strange putting 'oil' over 'water.' Maybe it makes more sense if you remember that the water in joint compound reacts with the compound- it's not just a thinner. Then paint with a latex topcoat.

Pay particular attention to sealing the edges and joints of the plywood. That end grain will soak up humidity like a sponge.


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## TJ Paint (Jun 18, 2009)

I think my idea is the best. 

Note: I may be biased.


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## CliffK (Dec 21, 2010)

fauxlynn said:


> Maybe I was thinking shellac, are shellac and lacquer the same thing (you know the stuff made from the Lac insect) ??? I don't know anything about spraying, but I do know that shellac prevents knots from bleeding.


 Shellac & lacquer not the same thing Lynn. You are thinking about shellac-which is an alcohol base(from the bug) and yes, you are correct-it is an excellent sealer.


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## mudbone (Dec 26, 2011)

If you choose to paint it make sure you two coat knots with shellac and that the knots are good and dried out in other words are finished bleeding out.I actually done some pine lumber last summer where I had to spot prime knots with 3 coats and followed by coverstain oil to keep it from bleeding.some other thread I think it was dawg said here on painttalk that alumium paint will seal knots permanate.


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## KEEGS (Nov 26, 2009)

May have to pursue the "Natural" look idea. PT members are right, plywood looks like trash most of the time when you paint it. Any thoughts on BM Arborcoat? Could I spray a Semi tansparent? Anyone sprayed arborcoat? I have used it on decks. Low VOC's, should be safe for inside? Could be dead wrong here but it is WB...Just throwin' it out there.


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## TJ Paint (Jun 18, 2009)

KEEGS said:


> May have to pursue the "Natural" look idea. PT members are right, plywood looks like trash most of the time when you paint it. Any thoughts on BM Arborcoat? Could I spray a Semi tansparent? Anyone sprayed arborcoat? I have used it on decks. Low VOC's, should be safe for inside? Could be dead wrong here but it is WB...Just throwin' it out there.


Check this out.


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## fauxlynn (Apr 28, 2011)

CliffK said:


> Shellac & lacquer not the same thing Lynn. You are thinking about shellac-which is an alcohol base(from the bug) and yes, you are correct-it is an excellent sealer.



Thanks for setting me straight.....and I can see why it would not be good to spray it.Someday I will learn how to spray.....


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## wills fresh coat (Nov 17, 2011)

TJ Paint said:


> Hell, If I was him, I'd just poly all of it and be done.


If it don't have any knots then it's the way to go but if it has knots I would paint it, the barn we did was all clear but he wanted it painted anyway


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