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Water resistance of water-based Minwax Polycrylic?

PostPosted: Mon May 15, 2006 12:01 am
by jmtk
I did a couple test panels using Minwax Polycrylic and Minwax Polyurethane to see what they looked like on my light birch after a few coats. I put 3 and 4 coats on each test panel (3 on one panel half and 4 on the other half). Then I was curious as to the water resistance of the water-based polycrylic vs. the oil base polyurethane. I let both dry for about a week, then I poured a little water on each. I was a bit dismayed to see that the polycrylic appeared to be rehydrating, since it got a whitish tint to it where the water sat (it's whitish in the can but goes on completely clear). The polyurethane showed no ill-effects at all from the water.

I really liked the idea of the polycrylic inside the cabin since it doesn't have residual odors, but now I'm wondering how water resistant it really is. How is it going to hold up if there's condensation inside? We'll be camping in sub-freezing temps so it's inevitable. Anybody have any experience with this?

Thanks!

Jeanette

PostPosted: Mon May 15, 2006 12:04 am
by rainjer
If It was me, I would not use any waterbased polyurethane. I use Vathane Diamond on a table & it has many white rings now.

PostPosted: Mon May 15, 2006 6:32 am
by cracker39
Jeanette, I'm not sure what the problem is. If it's inside your sleeping area, unless you'll be tossing the contents of your coffee cup up on the wall, how is it going to get wet? I'd think that on an interior wall, water resistance is a moot point. A shelf for placing cups or glasses of beverages might be a problem and need poly on it.
:thinking:
I used Minwax Polyshades for staining/varnishing my cabinet frames and counter top, and several coats of clear gloss Minwax poly varnish on the top to get a hard surface, and I don't have any noticable residual odors when I go inside. But, then, my wife says I can't smell anything very well anyway. Maybe that's a blessing.
8)

PostPosted: Mon May 15, 2006 6:45 am
by 48Rob
Dale,

In theory, the interior of a tear should stay quite dry...assuming there are no leaks. :thinking:
However, in reality, the interior can, and generally does, get wet.

It depends on the climate of course, but in your average humidity climate, simply sleeping in it on a cool night will raise the humidity level very high.

Best case; condensation dripping off the windows down the wall.
Worst case; beads and drops forming on walls and ceiling panels.

Water based products may well be less toxic, but if you want to seal wood and not worry, use oil based products.
Water based products have improved lately, but still aren't quite there...

Jeanette, Sealing the surface is important, but sealing the edges where water will seep is the difference between rotten wood and a long lasting trailer.

Rob

PostPosted: Mon May 15, 2006 7:32 am
by cracker39
OK, I guess I'm speaking just for myself when I think about it. If you knew my wife, you'd know that condensation inside my TTT shouldn't be a problem. She hates humidity. If it's humid and we can't have the A/C running, we won't be camping.
:cry:

PostPosted: Mon May 15, 2006 8:02 am
by Kens
I went one step further. I bought MINWAX HELMSMAN SPAR URETHANE CLEAR GLOSS INDOOR/OUTDOOR just to be sure.I don't notice a strong smell. I have been putting it on everything that needs a shine.You need a few coats goes on kind of thin. Kens

PostPosted: Mon May 15, 2006 9:53 am
by Todah Tear
JMT,

I used Minwax Polycrylic on one interior wall, but I used the Helsman on another (by accident of course). After a day of so of venting, there were no fumes from either.

After I get done withe build, I plan on heating the garage up with my kiln to let (The tear is in the garage) all of the fumes that need to efuse escape before I take it camping. Hopefully, that will work.

Todah

PostPosted: Mon May 15, 2006 11:12 am
by jmtk
Thanks for the replies, folks. I'm leaning toward the oil-based Minwax polyurethane at this point. The test panel seems to have aired out really well (I keep sticking my nose on it and taking a good whiff), so I'm thinking it'll be good.

Dale - As a Florida guy, you probably don't camp in frosty weather! We live in a fairly arid climate, but even in a tent that is pretty well ventilated, most cool mornings we wake up to damp tent walls, and sometimes even dripping walls. So my concern was how the water-based stuff would hold up on those days where we may have wet ceiling and walls from condensation.

Jeanette