Major checking on walnut - what to do?

[Adam Blanton]

This is from some local (Texas) walnut I picked up about 7 months ago. The ends were painted and it's been in my garage since then. I rough turned the bowl, soaked it in DNA and let it air dry for a few weeks. Mounted it to turn again and this is what I'm seeing... any suggestions on how to manage this? Is the wood salvageable.. should I ignore and just finish turning it? Or is this just the way the walnut cookie crumbles?

This is the 2nd piece I've had with similar results. I'm using carbide tools for this, would that have anything to do with this?



271994

[Dennis Ford]

Those checks are evidence that the wood dried out too fast, either before the rough turning or afterwards. Drying wood in the summer time is difficult, hot dry days cause rapid drying with resulting checks and/or cracks. This piece may be too far gone. I don't believe your tooling is to blame at all.

[charlie knighton]

burn baby burn, or time to add some art work, your choice

[Dale Miner]

I suspect the checks were in the piece when it was roughed. Even though you sealed the ends, the sealer only delays the eventual checking. The pattern of checking in your piece is common on the ends of logs that have been cut a while.

Typically, when walnut rough outs crack during drying, it will be one or two major splits.

As to what to do, no recommendation except for 'play it safe'.

[Sid Matheny]

Yeap dried to fast. If you are really wanting to save the piece a soaking of thin CA and a light cut to finish may help.


Sid

[Scott Hackler]

Also, from my experience 2 weeks after a soak in Dna is not long enough for walnut. Walnut takes forever to fully dry, even after Dna soaking. Here in Kansas, I will have to wait a minimum of 4 weeks and sometimes 6-8 weeks. I also fully wrap my soaked rough outs with 2 layers of newspaper and cut open the bowl opening before sitting it low to the ground in my climate controlled shop.

[Adam Blanton]

Awesome replies, thank you everyone. I do have some more walnut from that original haul, I may try rough turning another one and coating it with anchorseal and letting it sit for a year or so. Fortunately I got the wood for next to nothing, so it's not such a big loss with these few. I'll just consider them practice.

[Don McClure]

When I rough turn green wood, I then soak it in DNA for a couple of days. Next I let DNA flash off for a couple of hours, then coat it with Anchor seal and bag it up in brown paper for a couple of months. Next I will let it sit out in the open for a couple more months before finish turning. This procedure has reduced checking and cracking to minimal. Coming straight out of the DNA to air dry especially in the summer is too much stress on most wood.

[Mike Cruz]

Couple of things, Adam...

How long did you soak it in DNA? Once you took it out of the DNA, did you wrap it? If so, in what, and can you explain your method? How long did you keep it wrapped? How long did it sit after UNwrapping before you re-turned it?

How even/consistent is the wall thickness from rim to bottom of your roughout? If your wall thickness varies from rim to bottom (even 1/4" on a small turning like this) the turning will dry unevenly. Though the real problem is when the rim is thinner than the bottom, not vice versa. Make sure that you pay attention to keeping it even. Some people use calipers, some use their fingers. Use what you need to. People keep saying "uneven drying", basically pointing out that parts dried too quickly. While true, we need to find the root of the problem. You see, this cracking could have been from when it was sitting on your floor (and you just didn't turn away the original cracks), or it could have happened after you took it out of the DNA.

Let us know these things, and maybe we can find out just what happened.

[Adam Blanton]

Ok, so I'm guilty of not wrapping it after the DNA. I had some decent luck setting some bowls out after the DNA without wrapping them, so I tried my luck and it is probably the cause of the checking.

This bowl probably sat out for at least a month after the DNA bath, I'm thinking more like 6 weeks.

The importance of keeping the walls a consistent thickness makes more sense to me now. I don't remember how consistent they were when it was rough turned, the bowl wasn't terribly uneven, but next time I'll try measuring with calipers to ensure it's all the same size. When I roughed the bowl, I don't recall seeing cracks anywhere near the amount I got during the 2nd turning, which leads me to believe it's from the drying process. I do have some more walnut in the garage that hasn't been rough turned yet, so I will see if I can get to some of that this weekend.

Lessons learned:
When rouging a bowl, keep the walls at a consistent size
Post DNA bath - seal/wrap the bowl and be patient

[Prashun Patel]

Those checks are very curious. I've rarely seen them that abundant, shallow, and in that orientation. That bowl is also quartersawn, no? Was the bowl stored upside down, such that the inside was prevented from drying at the same rate as the outside? How thin was the bowl turned?

Don't DNA it. Just anchorseal it. If you have patience, it's really the easier (to me) way to do it. Also, A Texas garage in the summer isn't probably the best place to let it age. Do you have some place inside that you can keep your roughouts? Huge variation in temp/humidity is your enemy.

On a quartersawn bowl, you might actually have the best luck just finish turning it green, to a thin, but consistent thickness. It shouldn't move very much at all. I would still let the bowl sit in a paper bag for a week or two to dry enough so you can gently sand it.

[Adam Blanton]

I do have a crawlspace under my house, it stays much cooler than the garage and may be a good place to store roughed out blanks.

Bowl was upside down on a high shelf in the corner of the garage. After 2 weeks they were turned right side up and stacked. This was the 2nd bowl with cracks like this, both DNA soaked after a rough turning, then the cracks became apparent after the 2nd turning.

Quartersawn, yes. The thickness of the bowl now is probably around or a little thicker than 1/2" . I didn't want to go any thinner with all the cracks. I may have enough walnut left to do 2 bowls, I can DNA one and air-dry the other and see if I get the same results. When I have the time, I'll try this and record some more information about the bowls around thickness, time spend trying and so on.

I'm still a somewhat green turner myself (pun intended) and I have not yet tried turning a green bowl to final thickness. When doing a green to final, should the walls be thinner than when turning a dry bowl?

[Mike Cruz]

Sounds like you have a plan, Adam!

After taking out of the DNA, wrap the roughout like a present. Then cut the center out of the hollow part of the bowl. That will leave the rim and outside of the bowl covered. Many people like to store the drying bowl upside down on a wire rack. Not sure that is necessary, but certainly doesn't hurt. Leave it like that for at least 2 weeks. Then, unwrap and let sit for another two weeks or so. You ought to be fine, then.

As far as using the calipers. I don't mean to say that you need to use "measuring" calipers. Rather the ones that have two large arcs. Lock them down on the widest part of the walls, then run them up and down the walls. You'll be able to see where you are "thinner" and by how much (no not by mm's necessarily), but generally. Again, thicker at the rim and thinner at the bottom isn't all bad. Thinner at the rim than at the bottom is a recipe for cracks.

Enjoy the rest of your walnut!

[Mike Cruz]

Adam, do those cracks go from the outside all the way to the inside? If not, you can turn away the cracks...but the bowl WILL be smaller. Yeah, I know we usually like to just "round" the outside, then take the meat out from the inside...to keep the bowl as big as possible. But if those cracks don't go all the way through, you might be able to turn them away.

The DNA was not the problem. It was the drying method afterwards that was. But we've already addressed that...

[Prashun Patel]

I think the issue was storing the bowl upside down. The biggest risk of cracks on a qs bowl is about 2/3 the way up on the edge, where the grain forms an oval as the walls go vertical.

[Adam Blanton]

I didn't see nearly as many cracks on the inside, but I'd have to check to be sure.

Is storing a bowl upside down a no-no?

[Adrian Anguiano]

use anchorseal and wait. patience is the best prescription.

I have a nice stack of grocerybags in the corner of my garage waiting :)

[Prashun Patel]

The trick is minimal and even airflow. If you store it upside down, the inside does not get to dry as fast as the outside. Also, if it got hot up there on the top shelf in your TX summer, drying would be accelerated on the outside but not on the inside, where the moisture could not escape. If two sides of the bowl dry at different rates, the wood can't evenly compress, so it warps, or cracks possibly one side and not the other.

This is all theory...

[Mike Cruz]

The upside down thing is spot on IF you are putting it on a solid shelf. As long as you are putting it on a wire or grid type shelving unit (think closet shelf from the BORG), you'll get the necessary circulation to dry the inside.

And certainly, AnchorSeal is a great method, but it DOES take about 6 months for that to allow the roughout to dry, and it isn't 100% crack free, either. I've had some woods crack like crazy with AnchorSeal. I use both methods...it just depends on how quickly I want to get back to that piece.

[Richard Coers]

how close to the end of the log was this piece taken from? Looks like checking that was there before you turned it.

[robert baccus]

If the checks are not already gunked up with wax, sealers ect you can thin epoxy or poly resin and fill them up. Takes several applications but is much cheaper than CA. Thin the resin enough to go to the crack bottoms. The stuff cuts off with a sharp tool afterwards.

[Adam Blanton]

I honestly can't remember, I cut up the logs some time ago and don't really remember what came from where.

[Dale Bonertz]

Adam,

Good responses but something not mentioned is the form. With a wide flat bottom like on this small bowl will cause problems also. The sides are also a bit straight up and down. Try to round your form a bit more and use a smaller tenon size so you don't end up with such a flat bottom. This will assist the bowl in its moving and you will experience less checking.

[Steve Rollinson]

Turquoise dust inlay would make you want more defects in you walnut!