Sealing Wood

The lumber I purchase from a saw mill is sealed only on the end grain. U-C Coatings the maker of Anchorseal refer to their product as an end grain sealer.

-- Jack Novak Buffalo, NY - USA (Remove "SPAM" from email address to reply)

Yep, they call it an end grain sealer but its primary use is for sawn lumber which is going into a dry kiln.

Bill

Nova wrote:

Need your opinion on sealing of green wood, in this case I am talking about a round split down the middle. One school of thought is that only the end (cross-grain) needs to be sealed and the side-grain left unsealed. Others say all freshly cut and exposed wood must be sealed. Who is right?........Ralph

While I agree with a lot of what Ray said. Here are some thoughts for you.

1. You may turn wood "Green" or "Wet". You either turn it very thin and even, then let it warp during drying or you turn it to a even thickness of 10 % of the diameter, put it in a paper sack, preferably with some of the wet chips, checking it weekly, till, it's dry, then finish turning it.

1. If you want to turn it dry, common sense and a little science come together to dictate what you seal. Since wood is really a bundle of straws, the end grain will dry much faster than the middle. Unhampered, it will crack or check, in time, all the way through. You have to seal the ends, so that moisture evaporates from the center evenly with the ends. The rate is basicly 1 year per inch of thickness to dry wood. The type of wood, humidity and temperature effect this time. However, if you sealed the whole piece, how would the moisture escape? I usually take the sealer one inch up the sides to make sure the ends are sealed. Since I'm cheep, I go to the Big Box, get "Mistake" latex paint for about 3.00 per gallon, and put two to four coats on the ends.

If you do this last with half logs, you will see the "Flat Center (side originally towards the pith)" has become convex when dry.

Just some thoughts from > I say do not seal the wood, rather leave it in lengths of at least 3

feet. This will allow moisture to escape, with some end grain checking. However, when you are ready to use some, go out, lop off about 3-5 inches, then cut your blank from there. When you are finished with the turning, it will not be as wet and may even be less apt to check. In my experience, many of my pieces are done this way and I have a low loss rate to cracking.

place where you will not touch it for about 2 weeks - preferably a paper sack or a cardboard box. This will keep the air off of the piece and allow the moisture to escape evenly. After about 2 weeks, hold the piece up to your cheek, if it is really cold, put it back in the box or bag for a few weeks and re-check again. When the piece gets closer to room temperature, that means the moisture is dissapating toward equilibrium. It is then safe to put it in a closed cabinet or other place where there is little airflow.

talking about a round split down the middle. One school of thought is that only the end (cross-grain) needs to be sealed and the side-grain left unsealed. Others say all freshly cut and exposed wood must be sealed. Who is right?........Ralph

Hi Ralph

Ralph the question is why seal the wood ?? The answer of course is that it (the wood) splits as it dries, because it dries a lot quicker on the end grain, that's where the first cracks appear, but wood also dries on the side grain, a lot slower mind you, but it does. As the wood dries on the outside it shrinks, (wood in a whole log can not do that without splitting), remember the hearth of the wood is still very wet, so it splits, now a log split in half is half as thick and able to give some as it dries, but it still will split if left to long like that. So to leave a log whole and the ends sealed, gives you some time before it will split, if the log is split in halve and the ends sealed you have a little longer, you could seal the whole log, it would help to keep it from splitting for a longer time, the same applies for the half log, but dry it will and the stress induced will split the wood, if not tomorrow than the day after. Keeping it out of the wind or draft, and out of the sun, will slow down the drying, keep it off the ground, or it may rot. The best thing is to use it, rough turn etc., or have it sawn in thinner dimensions and dry it that way.

Have fun and take care Leo Van Der Loo

Ralph J. Ramirez wrote:

Seal a round split down the middle on the end grain. Wax emulsion is good, old wood glue, old latex paint, piece of plastic loosely tacked will work about as well.

Leaving the bark on and the log in the round, sacrificing some length each time I get back to it, is the way I go. End checks are self-limiting, so you can keep the ends of your log sheltered, sacrifice an inch or so, depending on species and climate, and turn with success. Once it's split, or the bark is gone, the money goes for a rough turn as the best way to save it.

You may read through the unscientific folklore below, or spend some time with chapters two and three of

to planyour strategy. There you will learn about the structure of wood, which is the key to anticipating direction and magnitude of shrinkage and compensating for same.

As you learn about FSP, EMC, and radial shrinkage, you can review the practice of sealing a rough with better data. One thing not covered is the mechanical action of drying turnings which squeezes the face-grain bowl, closing off any incipient checks on the inside curvature, exacerbating any on the outside. Sealer on the outside, or total humidity control are the most common options, each with proponents, and each accomplishing the same thing, controlling the loss from end grain - there is effectively no face grain - to a rate at least equal to the capillary draw from the interior.

Need your opinion on sealing of green wood, in this case I am talking about a round split down the middle. One school of thought is that only the end (cross-grain) needs to be sealed and the side-grain left unsealed. Others say all freshly cut and exposed wood must be sealed. Who is right?........Ralph