Drying a tree slice

Re: Drying a tree slice

Bill Tindall, E.Tn.

Slices like you have typically develop one crack that opens pie shaped. I expect it will open several inches. The opening can be readily calculated from the ratio of radial to tangential shrinkage. If you make a cut radially from the perimeter to the center that is where the piece will open and likely no where else.

It will dry in weeks in your climate. Moisture loss through end grain is about 10X faster than through the sides.

Whoever said 1" per year has read lots of magazine articles but never dried any lumber. It is a useless guideline.

Re: Drying a tree slice

Bob Deen

Thanks! What about cutting out the center, leaving a big donut or ring? Is that likely to help? Seems unlikely to hurt, anyway, since I need to ultimately do that anyway to make a fire pit table.

For the (non-ring) disk, I think I'd prefer a natural look to the crack so if it's likely to be just one big one, maybe I'll just let it do its thing naturally.

Re: Drying a tree slice

Bill Tindall, E.Tn.

"What about cutting out the center, leaving a big donut or ring" I don't know.

Re: Drying a tree slice

Barry Irby

I think the theory behind the "donut hole" is that the outer rings dry faster than the center ones in a log and try to shrink while the wet inner ones stay full size. In this case I don't think the same is true. It could dry uniformly, but since the outer circumference is larger it may shrink more. I don't think removing the plug will hurt anything.

One way people do this is to slice into the center and let it crack. Then they take a carefully matched slice of (redwood) pie out of the other piece and fit it into the wedge. Done really well its pretty good. Still visible but not as objectionable as a crack.

This of course will probably ruin your other piece. But not necessarily. You may be able to cut it in two, straighten the edges and put it back together even if you get an oval.

Re: Drying a tree slice

John K Jordan

I've never had wet redwood or know about drying it specifically. I do know that some species crack and split horribly and other don't. For example, local hardwoods like dogwood and cherry can get radial cracks - dogwood might open up 10 degrees. Other species, such as eastern red cedar, might not. I've had cedar rounds not split at all. I have zero knowledge about how redwood behaves.

If you had access to several slices perhaps you could try several things. Let one dry as is. Make a radial cut on one. Wrap one in layers of paper to slow the drying. I also wonder if you can do something on the hidden bottom to relieve the stresses.

I've seen plenty of pictures of redwood slices made in to furniture and things, some with no cracks. How were these treated and dried? One thing might be call some of the suppliers of such slices and ask them for recommendations.

JKJ

Dry it slow- really slow

John C Lucas

Ie only had a couple.of larger slices over the years. Have one right now that is 22" out of whire oak. It is drying on a shed with water that runs through it every time it rains. Its doing well so far. I will go out and measure the moisture content i a few minutes.

I have dried lots of smaller ones on the 6 to 8 inch range. I put them in plastic bags and turn the bag inside out e ery day for.the first few months. After that i put them in a paper sack. For species.that i know crack badly i keep.them i the plastic a lot longer. The plastic bag slows the drying tremendously but would probably be a pain for the size you are talking about. I think you would be ok to simply put the bag over it leaving the bottom loose. Leave.it on concrete somewhere so.you wont get bugs. The reason for turning the bag inside out is to speed the drying and to.reduce the mold so if you forget cor a few days no problem. Logs.typically dont even remotely follow.the year per inch ( which is just a remote guidline anyway). However since your drying mostly end grain it does follow it somewhat.

Example

Bill Tindall, E.Tn.



Shown is a slice of white pine, 19" diameter, sliced in 6 seconds by a 2 man cross cut team in the Woodsman Days event at Booneville, NY 2015. White pine will dry about like redwood, so I would expect the same result, just a bigger "piece of pie" missing.

Re: Dry it slow- really slow

John C Lucas

I lied. Its Ambrosia maple. 2" thick 18" in diameter. It was cut just a little over a year ago. Its down to 14% and in that area most of th lumber is around that. It will go.down a little bit in the winter. I may move it to my shop which is heated and no water leaks. Might get it down to 11% then. Maybe i can talk my wife into letting me store it under the couch after that to get it down to whatever my house equilibriam is before i make a table from it.

If you were a turner

John lucas

There is a trick us turners do to avoid cracks in end grain slices. Turn them thin and cone shaped. The reason the wood cracks is the outside is drying and shrinking faster than the inside. Since the inside is now bigger than the outside some thing has to give so you get a crack . If you turn the wood thin it can warp instead of Crack. It's hard to control the warp on a flat piece. If you turn it cone shaped as it warps it stays pretty much cone shaped but will get taller with the wood movement.

Removing the pith and some of the surrounding woof helps but not as much as you might think. If you don't want to do the plastic bag trick I mentioned above seal both sides with at least 2 layers of end grain sealer and put it somewhere out of the sun and wind and off of

F the ground. It will take a lot longer to dry but it will dry with end grain sealer on it.

Re: Example- question

Stuart Johnson

Out of curiosity what would happen if a steel band was clamped around the disc when first cut and then allowed to dry slowly?

Re: Example- question

Don Stephan

Green wood shrinks both along the growth rings, or tangentially; and across the growth rings, or radially. So a disk gets smaller.

Control the crack then patch it

Tom dunlap

This is a procedure that I read many years ago. The tip came with result pics too so and it makes sense.

Ideally you would have three slices but two should work

We all know that there will be a radial crack in most circumstances. By making a radial cut with a bandsaw, circle saw or jig saw you're letting the slab

Dry without the radial tension tearing a ragged edged crack

Now, to patch. Make the same relief cut in the other slice/s but make

Them in another place on the slab

Once the slabs are dry you stack one on top of the other and cut a pie shaped piece to fining the radial crack you created. With some fitting the pie patch piece might not even be visible

When I first read this suggestion the woodworker included pics of

Each step. On most of the finished pieces the patch lines were almost invisible

I've never tried this patch but I know it would work.

Right now I have a 5' tall 26" diameter hollow ash trunk drying. I watched both ends for a crack. When the first crack appeared I used my circle saw to cut a ' vertical' relief cut. Right away the cut opened to ¾". Its now about 2.25" and there are no other cracks in the hollow log

When the trunk is dry I'll make another cut 180* cromnthe felief and then it one of the two pieces in half again. The 90* pieces will

Be doors for a cabinet. I'll use quarter sAwn ash fornthe shelves top and. Ottom

Redwood ain't like white Pine

Clint Searl

Redwood behaves more like Catalpa or Butternut and probably won't split.

Re: Redwood ain't like white Pine

Clint Searl

Redwood over 4' wide

Butternut 22" wide

Re: Drying a tree slice

Bob Deen

Thanks to all who replied. Since there are two slices I cored one (making a donut) and left the other alone. Partly just to experiment. I'll try to post the results after they dry.