Question about drying walnut

[Jon Nuckles]

I just cut up a bunch of walnut (see my related thread for pictures) and am ready to start roughing out some bowls from it. I also unwrapped a walnut bowl I had roughed out about a month ago and found a huge crack down the side (sorry, no picture). I had not previously found walnut to be especially prone to cracking. The blank was wrapped in brown paper with a one inch hole in the paper on the "inside" side of the bowl. The piece did not contain any of the pith and it was of pretty consistent thickness. The only thing I can think to do differently is to wrap my rough outs in plastic grocery bags (perhaps with shavings) for the first week or two to slow the initial drying more. Maybe I just wrap them in paper, but don't cut a hole until a couple of weeks have gone by? I don't have air conditioning in my shop and the heat and humidity has been high in Chicago this summer.

In my current achy state from all the work to get the blanks cut and sealed, I don't want to lose any of my rough outs to cracking. I don't care for the look of (my) pieces turned thin and allowed to warp. I really don't want to have to anchorseal my roughouts. Any other ideas?

[Roger Chandler]

John,

Do you do a DNA soak before placing in a bag?

[Jon Nuckles]

Roger, that is a good question. I have not DNA'd anything yet. I have mostly focused on slowing down the drying to allow the moisture to migrate out equally on its own. I am not in a hurry to dry my pieces and would prefer not to add the labor and expense of the DNA process if I don't have to. I am spending most of the summer months building up a good supply of rough turned pieces so I will have plenty to finish turn when winter comes. I should go into business making rough turned bowls for other turners to finish; I love throwing green curlies across the room and I hate sanding. The only downside is my wife keeps asking where the finished projects are. :eek:

[Roger Chandler]

Jon,

At bare minimum, I would either DNA soak [couple gallons of DNA in a bucket, and you are good] or at least coat with anchorseal.........you will still get cracks but more slowly, and may give you time to get most of the moisture out, then rough turn and hopefully catch it before it splits.........

I would cover the entire blank not just the ends [just me] but I think the DNA soak is easy, and effective for the most part, once you rough turn. The bags I understand are a must for creating an environment in which the slow drying process can be controlled and you will likely get the best results using a combination of DNA, anchorseal and bagging.............that is most likely the best you can do unless you build a kiln.

You are correct..........black walnut is prone to cracking.........I have a number of pieces I will have to cut down to smaller blanks because they did crack, even with heavy coat of anchorseal on them.

[Jon Nuckles]

Roger,

Now I am a bit confused. Are you suggesting doing a dna soak of the blanks before roughing? I do anchorseal my blanks when I cut them - - a liberal coat on the ends, knots and first couple inches of face grain from the ends. I haven't had problems with blanks cracking before I rough turn them, at least nothing I can't cut away when bandsawing them round, as I leave the blanks several inches longer than they are wide. Maybe I will experiment with the current batch and see what method works best for me. I had not heard that walnut was prone to cracking before. I have had some bad experiences with cherry cracking (a shame for me because it is my favorite wood) and I have heard oak is tough to dry.

What woods do dry easily? I generally take what my tree cutter offers, but I'd like to let him know what I am most interested in.

[Roger Chandler]

Hi Jon,

Rough turning, DNA soak, anchorseal and bag..........about as good as you can get without a kiln. Walnut will crack, cherry, apple and oak.........all prone to crack ..........they seem to have significant movement along the length. You have stated correctly the best way to handle black walnut....[leave it long so you can have some to cut off] I just have covered my entire blanks that I cut out, but log pieces still have bark on them, so I just coat the ends of them.

I have found maple and catalpa to crack much less, however maple will crack as well........some of it depends on the way it is stored........outside vs. inside, in shade or not, covered with a tarp or exposed to rain, etc..........all are variables that will affect the cracking issue. There are some others I have that I have not gotten to yet.........chinese elm........not too bad, and mulberry........that one I have had for a number of months [log form] it has only a couple of shallow hair line cracks at the pith so far, but I will cut it in half before long and coat it with anchorseal as well.

[Jon Nuckles]

I have limited experience with mulberry. I roughed out a really nice natural edge bowl but the sapwood under the bark cracked while drying. The bark is still firmly attached and did not crack, so I may fill the crack and finish turning it. I had the opportunity to get some apple, but turned it down because of what others have posted about the difficulty of drying it without cracking. I love maple and would like to turn some really large bowls out of it. Strangely, though, I haven't had the chance to get any this summer despite the number of maple trees in Chicago. Soon, I hope.