DNA drying help needed

[Jay Drew]

After reading all the glowing reports of DNA drying I decided to give it a try but it hasn't gone well. I rough turned 4 Box Elder bowls most of which were 10" in diameter and about 1" thick. I soaked them for 1 week and folded 3 or 4 full sheets of newspaper over them. I taped the paper on the bottom of the bowl and cut a hole in the top exposing the inside of the bowl. I leaned them against each other on a self so that the opening wasn't totally covered and left them there for 3 weeks. When I unwrapped them this past weekend I found that they had checked so bad that I now have 4 strainers! What am I doing wrong?
Is Box Elder hard to dry without cracking?
Do you trim the paper to fit so that you don't have thick layers of paper on the bottom from all the folds?
Is 3 to 4 layers of paper to thick?
Is there something else I am overlooking?

Thanks in advance for the help!

[Patrick Taylor]

To me it sounds like you're doing things right. A week of soaking might not be necessary but shouldn't hurt. You could try just overnight instead. Is the humidity especially low where the blanks are stored? Frequent changes in humidity or temperature?

For me, I just rough the bowl, soak overnight, and stick it on the shelf without wrapping at all, so don't get too hung up on details. Just experiment to see what works in your climate and shop conditions.

[Barry Elder]

On Dave Smith's web site he shows letting the roughed bowl dry upside down on an open rack. Another thing you didn't mention is how long you air-dried them before covering them with paper. IIRC, he says one hour or so.
While DNA drying is not the answer to all problems, I have soaked over 20 different varieties of bowls and have had no cracks (one exception) but the bowls still continued to warp. Exception was fresh Golden Rain Tree.
On the other hand, the old paper bag full of wood shavings stored away for a while has resulted in not having any cracks either. Different strokes!

[Ralph Lindberg]

You've found the dark side of DNA, it doesn't always work.

Fred Holder is (was?) a long time believer in DNA drying, he did a small study, using blanks cut from the same walnut tree. He found no differences between the blanks that got DNA and those that didn't.

Reed (RoboHippy) looked at even more samples, and found that he couldn't tell if it was doing any good (the same with LDD, but he continues to use LDD, as he likes the effect it has on finish cuts)

I had occasion to talk a "pro" at a lumber mill that had read a professional study, what they found was they couldn't predict the results. Sometimes trees of the same specie, and grown in the same area, produced different results; sometimes the same results. They could find no way to predict the results. Between the higher costs (the conventional drying) and the unpredictably of results, industry doesn't use it.

[Steve Schlumpf]

Jay - sounds like you are doing things correctly but just to be sure - check out Dave Smith's site or http://www.woodcentral.com/cgi-bin/readarticle.pl?dir=turning&file=articles_473.shtml which has some photos of how bowls are wrapped.

I have never turned Box Elder - so can't comment on whether it is procedure or the wood. I turn mostly birch, maple and cherry, let the bowl soak for a few hours and then dry them out enough (1/2 hr) that the plain brown paper bag I wrap them in doesn't soak up lots of DNA.

So far the process works great for me. I have had a couple of bowls crack on me but they had very small cracks in the blanks before the drying process started.

Best of luck to you and stick with it - the process does work!

[Jay Drew]

Thanks guys for the quick replies.

To answer Patrick's questions:
I only soaked for a week because I don't usually make it out to the shop during the week so they soaked from Sunday to Friday night.
Humidity and temp change a bit because the shop isn't insulated yet and the temps have been moving around quite a bit in my area.

Ralph, What is LDD?

Barry, I let it dry for only 10 or 20 minutes before covering would this make a difference? I also thought about the rack but I didn't have one so I tried to place them so the most amount of air could circulate around them.

[Jay Drew]

Ahh.. LDD = Liquid Dish Detergent

[Jay Drew]

Steve,
Do you leave the entire top of the bowl open like in that article? I only cut a 3 or 4 inch hole in the center of the paper.

[Don Robert]

Here is Dave Smith's report on his studies of using DNA in case you missed it.

http://www.woodcentral.com/cgi-bin/readarticle.pl?dir=turning&file=articles_473.shtml

I've got my first green bowl soaking as I write this so I can't tell if I have had success with the method.

[Keith Burns]

Jay it sounds like you are doing it right. I only use 2 sheets of newspaper and on a bowl leave the top totally open. The one question I have is have you left the pith in ? I did a couple of American Chestnut HF's recently with the pith on the bottom and they cracked beyond usfullness.

[Jay Drew]

Keith,
No pith but I am trying only 2 sheets of paper with the top totally open now. I also got a rack to put them on. Hopefully this works. If not it is back to air drying which has worked well for me.

[Dennis Peacock]

Jay,

The idea is to soak, take out of the bath, wrap in 2 sheets of newspaper or brown paper, cut away the paper that covers the inside of the bowl, turn the bowl upside down and place on an open rack or anywhere you can leave the inside of the bowl exposed to the air. The overall objective is to get the entire bowl to dry through the inside opening of the bowl helping to draw the wood towards the middle inside of the bowl as possible.

Keep us posted as to your progress and post some pics and we'll help you through it. :)

[Bernie Weishapl]

Jay I had the same problem with box elder and another wood I can't remember now. I talked with Dave Smith and he told me to put them in a cool dry place with not to much air movement. I had left them in my shop and I don't run the AC when I am not in there so it gets really hot and there is low humidity. He told me the wood was drying way to fast. So now I take them to the basement of the house and stack them about 2 ft above the floor. Haven't lost one since. It doesn't matter if they are in the DNA for a week. I have left them that long with no problems. I always wrap mine in brown grocery sack I found works best for me.