so I got this hunk of barnwood

Actually 2.
But the question revolves around 1.
It's for my mantel. It's 4" thick and about 13" wide x 5'
It's in pretty rough shape but I want to just seal it and keep the characteristics of the old wood. Any tips?

Here's a couple more.




As you can see it's pretty rough. This is really old lumber.

Are you going for the 'old wood' look, or you want to keep the new wood color? Most instances that I've seen of wood re-use has been just letting it age naturally. My mom wants to reuse a lot of wood from our old barns in her new house. It's a cool look.

No idea on the sealing if that's the route you want to go. Maybe Johnson's Minwax?

I don't like min wax. If you set anything warm or damp on it, it's white ring city. I know.. I made the mistake of doing a kitchen table (antique) years ago.
I do want to fill some of the places it's pretty bad and splitting.
Perhaps with just layers of polyurethane or something?

[lynchmob]

I'd be sure it's dry(most likely is if it was under roof).I'd say use a sanding sealer for a primary coat and your choice of a poly finish(satin,gloss etc).
This thread must be pretty young because Knothead would be making a suggestion or two by now
HTH
lynch

[RedFury]

Water based polyurethane will only slightly color the wood, yet give it a hard layer of protection. It dries fast and can be applied with any common painting pad. I don't know if you can get it in smaller doses than a gallon though and it goes for about 35 bucks a gallon.

You might be able to bring a clean container to a hardwood floor shop and see if you can buy a smaller amount from them ( perhaps some of poly they don't plan on using...trust me, if it's a big enough shop, they'll have something )

I used ProCoat Millenium water based poly on my kitchen cabinets and they turned out nice. The best part was being able to put 3 coats of finish on in 1 day.

Most water based finishes these days are catalyzed when they are exposed to air, but the strongest of them are chemically catalyzed and once they are catalyzed they are good for about 4 hours and then the leftover finish turns into a big white eraser looking lump of worthless garbage. Extremely durable finish though, and usually thicker.

Oh yeah, forgot to mention oil based finishes! They take forever and a day to dry, usually bring out the colors the deepest, and go on thicker than most waterbased poly. The most durable I've found are suitable for use as a finish coat on floors. They are more forgiving to work with, which is why they are so popular over water based poly, which can be difficult to use depending on the circumstances and the waterbased poly used ( watch out for bubbles@! )

See how on the left of the top pic it's trying to lift and split? What do I use to "glue" it down so I can sand it real good?\
Also would I want to litterally "fill" the cracks in the wood with the poly?

Since we are on the subject, of poly and wood.
We are also doing a room in knotty pine and I was thinking an oil based poly would be nicer because it will yellow more than the water based won't it? I really like the patina of old varnished pine wood. I was hoping to duplicate that look (even if it takes a few years of aging in the den )

[thekingofpain]

Watco oil on the pine---ive done nothing to mine after 12 years and both pads are covered with it, im sure a 2nd coat would revitalize it but im not that ambitious :-)

Nice piece for a mantel, dont look like a funky hunka barnwood to me, someone has resawn it and given it a bevel at some point, it just might need to be resawn again which would clean it up but might take alot of the character away that it already posesses----guess itl have to be cut anyways to dimension---I like natural wood finishes (oil) or a poly thats waterbased and not shiney---my kitchens red oak, bathrooms teak and the rest is the angled pine T+G--- I like it :-)

Actually Tim, the hunk is going to fit as is. It's a floor to ceiling (8') see though wood burning fireplace. One hunka wood for each side. An old man (80ish) hand planned it. I'm going to do some sanding but not enough to sand out the worm marks.

If you use sanding sealer before applying the poly, just make sure you sand it first (before applying the poly). The sanding sealer swells the wood grain on the surface allowing you to sand the wood flat giving you a finer finish when you apply the poly.

Oil based poly will darken more than yellow over time when it is applied over pine. It does look very good.

I suggest the use of sanding sealer over the knotty pine before you apply the polyurethane. It will help you to seal the knotholes. If you need to apply more coats of poly, sand between coats. This will take any residual dust out of the finish, rather than sealing it into the finish. It also gives the surface "tooth" for the next layer to adhere to.

You may need to go back over the wood before it dries with more polyurethane and brush more on to the knotholes, as they will soak up poly. If you do this while the surface is still wet, you will not notice any lap marks when it dries.

Make sure you sand and brush with the grain. And make sure if you spray or roll the finish on, whether it is the sanding sealer or the poly, you back brush it. It will force the poly into the wood, where you want it.

A substitute for sanding sealer can be made from thinning down polyurethane, although it is a rather poor substitute.

If you want a super glossy finish and don't mind a little darkening, go for spar varnish (marine spar varnish)

I wish you were going to post this this morning. I could have posted pics of the process from start to finish as that is what I was doing all day. We've done dozens of knotty pine cabin interiors this spring. I could have shown you the differences between the semi-gloss poly, gloss poly, and spar varnish, as well as the affects of age and water as well as sun, wind, and ice on the various finishes.

I'll try to get a pic of a 100' knotty pine ceiling I spar varnished last year. It is in a dining hall. Absolutely beautiful...