Denatured Alcohol & Cherry Bowl - Radial Checks

[Marty Tippin]

I roughed a large cherry bowl over the weekend - about 12" diameter, 6" deep with 1.25" wall thickness. 24 hour soak in DNA then removed to dry in my fairly cool shop. Less than 12 hours later, I've got major radial checks all the way through the bowl. Disappointing to say the least. I got side tracked and wasn't able to cover the outside with grocery sack paper, but I'm not sure it would have made any difference in this case. I've got another rough bowl turned about a month ago from another log out of the same tree that's been air drying in my shop and it shows no signs of cracks or checks.

Too long in the DNA? A known hazard when working with cherry?

[Dennis Ford]

I don't do the DNA method but am sure the problem was too rapid drying after the DNA soak. Cherry is prone to cracking during drying and needs to dry slowly.

[Sid Matheny]

Soak 24 hours and make sure to cover the outside and rim and I always put shavings inside.

Sid

[John Keeton]

Let me preface these comments by saying I am not a bowl turner. However, over the past year, I turned a dozen rough outs just to have so that I can turn a bowl every now and then. Four were walnut, four were ornamental cherry, and the others wild cherry. All are 12" or more, and most were done in an ogee pattern, but about four were just salad bowls (hemispherical.)

I have had 100% success simply turning them to around an inch thick - all edges rounded, and immediately applying a liberal coat of Anchorseal to the exterior only, lapping over the rim to cover the inside edge. I toss them under my work bench - not stacked, for a few weeks, and eventually stack them just for space considerations. They will stay there until I get the urge to turn one of them. They warped, of course, but none of them cracked. My shop is not air conditioned, but it is insulated so it rarely gets super hot inside. If I am in there during the day, which is often since retirement, then I have the windows and door open and a fan going. At night, it will cool down considerably inside and stay cool during the day if I am not using it. I do heat it in the winter to about 55*, or so, and leave on the heat all winter.

Things might work differently in Kansas, but for our conditions here, I am pleased with this method. It is easy and the only cost is the Anchorseal.

[Paul Engle]

Fruit woods defy logic when it comes to drying . Some have success and other not so much . If you fill the radial cracks with say powered coffee grounds or other contrasting media using CA glue as the binder , you can had some unique character to your work giving it that spider web look and people will ask you how you got them that way !

[Roger Chandler]

I agree pretty much with what John Keeton said above. That being said, I have used the DNA soak, but it is important to get them wrapped and bagged, because without that part of the process, the drying is too accelerated. Cherry, apple and other fruit woods are indeed problematic, more than say maple or ash, but you need to follow through on the bagging and covering part..........shavings in the bag are not a bad idea, as that will help slow down the process even more.

The anchorseal process that John describes above is a pretty good way to do it.........about the only difference in my process is that I do bag the rough out........and coat the inside end grain............results will vary some with humidity, the temperature of your shop environment and such, so the more you control those issues the better the results obtained.

[John Keeton]

Regarding coating the interior, my reasoning (however flawed) is that I want drying to occur only from the inside surface of the bowl, but I do want that surface exposed to encourage drying. Should the bowl dry from the exterior, then the exterior surface will contract while the interior remains stable (wet), and that is when cracks are likely to occur. The exterior cannot contract in size because of the stable interior.

Just the opposite with sealing the exterior. The interior shrinks as it dries, pulling the exterior inward. The exterior surface doesn't contract, thereby minimizing the chance for cracking.

My roughouts have sufficiently dried within 3-4 months, and that suits my schedule. It may not work for others. I rarely am in a hurry to turn a bowl!!

[Don McClure]

I have done hundreds bowls using the DNA soak for at least 24 or more hours. Living here in the hot south, my shop is air conditioned which really complicates the drying process. I always us original Anchor Seal on the exterior and rim plus always bag my bowls for 2-3 months before exposing tem to room air. This gives me a high rate of success with most all woods. In the winter heat in the shop also complicates drying. Fall and spring are best times for drying rough outs here,

[Marty Tippin]

Thanks for the input. I'm hoping I can salvage some of this bowl and will give some thought to Paul's suggestion to fill the cracks.

My first DNA effort a week ago on a couple of mulberry bowls went very well - they're almost ready to finish after only a week with no cracks anywhere. So I was hoping the cherry bowl would come out just as quickly. Probably should have bagged it. Live and learn I guess. I did soak a couple of black locust bowls at the same time and they're both looking good (save for a crack along a bark inclusion that I didn't notice).

Being relatively new to bowl turning and generally impatient by nature, I'm in a hurry to build up a supply of bowls that are suitable for finishing. But if that's not going to work for cherry so I'll use anchor seal instead...

[Lloyd Butler]

Marty,

It could be that your Cherry blank start out a bit short, so the ends dried and started to crack and you did not have enough material to cut away the cracks while peeping the blank, so once the bowl was turned, the cracks just continued on.

[Bob Bergstrom]

There are quite a few variables that can cause a rough outs to crack. The wood, how much shrinkage the wood does, how centered are the growth rings, how vertical are the bowls walls, time of year or temperature and humidity of the environment, or type of sealer. Bottom line is there is a learning curve in drying wood successfully. Sometimes no matter what they just crack. Just build up a bunch and some cracking won't be as catastrophic.

[Fred Belknap]

Drying turned blanks is kind of an art. I have tried DNA, boiling, Anchorseal, and shavings. I forgot microwaving which also works. My shop is heated in the winter but no air conditioning. Coating both the inside and outside with Anchorseal has proven to be the most effective method of drying roughed out blanks. I still have a few failures. When a bowl cracks I examine it to try and find the reason it cracked. Most of the time it from a knot or pith. Sometimes I can't find a reason. I do a few hundred bowles a year and maybe loose a dozen to cracks. Cracks can easily be repaired with epoxy but since most of mine are sold I usually just toss them under the corner of a work bench. Maybe I should have a crack and dent sale.

[William Bachtel]

I have anchorseal ed thousands of bowls,and I have 98 % success rate, the cracked ones are from bad wood, or my doings. 1-888-end coat use the original , not the newer stuff.

[Gene Hintze]

I turn almost exclusively Maple, Cherry and Black Walnut and have seen no difference in the different woods when it comes to my DNA drying method. I rough turn to a wall thickness of 1" to 1 1/4", round the edges (unless I forget to) and pitch them in the DNA barrel. When I finally remember they are in there (I never soak for less than 24 hours and prefer a multiple day soak) I pull them out, let them air dry on the driveway in the shade for a couple hours and then put them on the workbench in my garage/workshop. I do not wrap or bag my rough outs for two reasons. #1 it is a pain in the butt to do so and #2 when they are wrapped/bagged you can't see when the checks start to form. I inspect my rough outs daily and when I see a check start to form I hit it with a tiny bit of thin CA glue. This process goes on for about 10 days and by then my rough outs generally stop checking. Living in NC where we deal with humid air most of the year I then take them into the house and pile them on the dining room table (there are 15 on the table as we speak) to dry in less humid environment. I still look them over periodically for checks but rarely find any at this point in the process. In about 90 days they are generally ready to finish turn. Using those species of wood and the DNA method I have described I have a zero percent loss rate on rough outs. Everbody does it differently but this method works for me.

[Dale Bonertz]

Being relatively new to bowl turning and generally impatient by nature, I'm in a hurry to build up a supply of bowls that are suitable for finishing. But if that's not going to work for cherry so I'll use anchor seal instead...

Slow down Marty. The best method to dry is allow the wood time (months) to come to equilibrium. Get a supply of wood and rough turn and keep rough turning and this will get you ready for finish turning (for the most part you use the same cuts). Look at rough turning as an opportunity to practice different cuts (roughing, scraping, shear scraping, push cut and etc.), rim styles, forms, forming tenons and etc. Before you know it you will have all kinds of dried blanks and you will have acquired the skills to finish turn them.