Best sealer for knotty pine

[waligators]

I'm getting close to being done putting knotty pine in my fish house. What brand is the best for sealing the pine, and is it best to brush or spray it on? I'm not going to stain the boards. I do not want any issues with warping so I'm thinking 3 coats minimum. Also, does clear coat go on after the sealer? Or is clear coat and sealer the same thing? Just want to do it right the first time!

[Hawg]

Sherwin Williams has a good sealer but expensive. 3 coats is overkill, 2 is good. All paint and stains/sealers are priced by the amount of solids in them. You get what you pay for. This stuff is around $40/gal.

[solbes]

I used Minwax Polycrilic (water based) poly inside our bunkhouse up at the lake. It's only 11x13' inside, so we wanted the knotty pine T&G boards to be as light as possible. As much as I like oil based polyurethane for other reasons, I didn't want this one to yellow. And it did not yellow at all, even 5 years later.

I applied 2 coats with foam brush, with a 400 grit sanding/tack cloth in between coats. No sealer needed. Its smooth and beautiful. It just ever so slightly darkened the white sapwood, and brought out the colors of the heartwood and knots.

[Hawg]

Solbes brought up a good point, stay with clear if you like the look. Many varnishes will be yellow by next year and houses are usually dark enough without more help from the stain or sealer.

[Tom7227]

Given the significant humidity changes you may want to leave the boards a little loose in the tongue and groove. The wood is going to expand and contract and it has to go someplace. If you have it in too tight at a time with low humidity you may have problems when it gets a chance to absorb some moisture.

Knotty pine is pretty pricey. Tongue and groove popple looks pretty good and costs a lot less.

[8ucksho7]

I used Minwax Polycrilic (water based) poly inside our bunkhouse up at the lake. It's only 11x13' inside, so we wanted the knotty pine T&G boards to be as light as possible. As much as I like oil based polyurethane for other reasons, I didn't want this one to yellow. And it did not yellow at all, even 5 years later.

I applied 2 coats with foam brush, with a 400 grit sanding/tack cloth in between coats. No sealer needed. Its smooth and beautiful. It just ever so slightly darkened the white sapwood, and brought out the colors of the heartwood and knots.

+1

Waterborne poly doesn't yellow and it dries fast too! This would be my first choice.

[PurpleFloyd]

One thing that would help reduce warping is to finish all sides of the boards and not just the exposed face.It sounds like it may be too late for that?

With the extreme changes in temp a Marine Spar Varnish gives more elasticity than either acrylics or poly's. That being said for the most part they will all do the job.

[David Anderson]

So I asked why my wood was not finished in my wheel house and was told that once sealed, the surface will end up with condensation when you first heat it. I don't know if this is a real problem or not but apparently the unsealed wood absorbs the moisture.

[jerkbait]

I would say that is true. The pine is finished in mine with polyurethane and it does get condensation on it for a little while when it is really cold.

[leechlake]

yes if you keep if unfinished the pine will absorb that moisture but you don't want that. As mentioned above the best thing would be to seal all sides of the wood but sounds too late for that. The pine was kiln dried most likely to approximately 10% and if you let it absorb moisture it will expand width wise, potentially buckle and also crush the wood fibers of each piece. Once it dries out off of the ice the wood will shrink, the wood fibers are crushed and then you have gaps. In essence each piece 1x6 pine which is 5-1/2" wide may get crushed a 1/4" and that get's multiplied by 2 since each piece is next to each other and you have a 1/2" gap.

It's hard enough to keep a modern home with air exchangers and humidifiers and air conditioners at the correct relative humidity and also most people don't know what that is. A ice house is a near impossibility. Very cold outside, people coming in and out, sitting on a moisture source, the heater. Those are the perfect storm for problems.

The colder it is outside the lower the relative humidity you want inside. You can google it but when it's -10 outside you may want the RH at 25% inside. If it's 40 degrees out you want it 35%. You will not be able to do that with an ice house so best bet is sealing the wood with a oil based poly or water based if you don't want it to yellow.

[Cliff Wagenbach]

If you do not want the pine to yellow, first give it a light coat of platinum colored stain. Then finish it with 2 coats of water based poly or better yet a spar varnish.

My pine has not expanded or shrunk in my house yet in 3 years of hard use.

Cliff