How do I keep wood from cracking as it dries?

H

Hesparus

Joined
Oct 31, 2004
Messages
1,442
I've been getting into working with wood, but I have been having trouble with it cracking as it dries. I've got this beautiful piece of maple that I cut a couple of months ago, but when I brought it inside it cracked so badly that it's now completely useless. Is there a way to avoid this?

- Chris
 
You can't eliminate it Chris but you can minimize it. Paint the ends completely with used motor oil, latex paint or any of the commercial products made for this purpose. That will cut the checking way down.
 
can you stabilize green wood? I would have thought it would have to be dried to some degree first.....

Doc
 
You cant have it stabilized until it is dry enough. You can melt parrafin on the stove top and dip the ends in it to slow down the drying process. Gun stock makers do it this way around here anyway.
 
can you stabilize green wood? I would have thought it would have to be dried to some degree first.....

Doc
 
Hi Hesparus

I've had some degree of success - particularly on nice pieces of wood - by sealing them with white or yellow carpenteres glue and giving them a year or more to dry before proceeding. The glue seems to slow the drying and also to keep the grain together, resisting and reducing (but not eliminating) the cracks.

Also, I cut large pieces into smaller, but still oversize, pieces. That way, a crack in one piece may not go all the way through another.

Stabilizing is an option but you take some risks. Note, I said you take some risks. Some stabilizing companies won't even accept wood that isn't already dry. They may have to start off by drying it - which may cause cracks, and as soon as they apply vacuum, they are sucking remaining moisture out - again resulting in cracking and warping. I got some briar burl a while back. Briar burl is kind of like manzanita. It cracks just looking at it. Everyone I know who tried wax, laquer, and pentacryl to dry it wound up with it splitting nearly to toothpicks. I cut it into oversize knife block pieces, wrapped them tight in saran wrap and sent it to Mike at WSSI with a note that I was willing to accept whatever consequences. It came back pretty warped and grizzled and some pieces were a loss but some of the oversize pieces sanded down to really sweet and completely stable blocks. Of course, I had to pay for the stabilizing even on the pieces that didn't make it - but I got something where others got nothing.

Good luck with your next batch.

Rob!
 
I use a product called "Sealtite 60", available from Woodcraft. It's a water soluble wax that goes on very easy with a brush, and then hardens.
I apply it to the end grain only.

It's easily removed by heating the piece of wood to 150-180 or so. It just disappears.
It's made specifically to help stop splitting as wood dries.

http://shop.woodcraft.com/Woodcraft/assets/html/homepage.asp
 
year or more to dry before proceeding.

As Rob said...slow. The rule is a year for every inch of thickness.
 
Do some woods crack more than others? I made a cane four years ago from beech and never sealed it or controled the speed at which it dried and I started to notice a little bit of checking about two years ago, but it was all very minor and barely noticable. A few months ago, I made a simmilar cane from ash and it quickly cracked quite noticibly around the head, but not on the shaft at all. This piece of maple, on the other hand, has been cracking everywhere and very deeply. Is this because of the woods I'm using, or something else I'm doing?
Also, with the painting the ends trick can I start working it before it dries, or do I really have to wait two years before I touch it again?

- Chris

P.S. If I leave the bark on, how quickly can I dry it?
 
Different woods crack differently. Beech is a very stable wood. That's why it was used for plane bodies in the old days. Maple is very stable after it dries but there is a lot of shrinkage during drying...as you are finding. Hornbeam splits something awful as does Oak.

Leaving thee bark on helps with long lengths but not on shorter pieces. Go out to the wood pile and look at the checking on the ends of logs with their bark on. What causes it is the moisture loss from the ends as opposed to the sides. Think as wood fibers as leaky water pipes. It leaks some to the sides but gushes out of the ends. The rapid loss causes the wood to shrink too quickly and splits.

Also, with the painting the ends trick can I start working it before it dries, or do I really have to wait two years before I touch it again?

You can't hurry Mother Nature. I have the rafters full of lumber for stocks and other things, air drying. You can build a kiln or have it kiln dried but Kiln dried lumber is not as stable as air dried. Give it time....God knew what he was doing when he came up with the rules for things.
 
Hi again Chris

Beech is a special wood because it's grain fibers are very long. Native peoples knew this (probably not the fibers but the properties) and used beech for brooms by shaving long thin strands along a stick and folding them back and tying them off.

I presume you kept that piece of maple because of interesting grain or figure. That figure shows because of different densities of wood and different grain directions. These lead to uneven drying and that leads to cracking.

The only way to avoid the wait would be stabilizing and you are going to lose some wood that way. By the way someone compared stabilizing to pressure treating and suggested it is hard to get more than 1/4 inch deep. The mill I worked at used an incisor to poke holes in the lumber and used pressure to get some penetration. Results were about 1/4 inch penetration.

Professional stabilizing starts with extreme vacuum and when the chamber is flooded and the vacuum removed, the penetration is excellent. One type of stabilizing uses colored acrylic monomers and you can see from the color that the penetration is all the way through. The biggest piece I've done was about 2' x 2" x 14" - with complete penetration. I have no idea what the limits are but they are certainly more than 1/4".

Rob!
 
You must log in or register to reply here.
Back
Top