cracking / checking white oak bowl

[Ron Bontz]

Several weeks ago I roughed out a green white oak bowl, 15" dia x 7" approx. I left this one about 1" thick across the bottom and sides. I soaked it in DNA for about 24 hours. I took it out and wrapped it in brown construction paper and set it about 12" off the floor, top open and facing down.
Yesterday I noticed some small checking in the inside of the bowl so, I unwrapped it and behold very large cracks were in the bottom and some smaller ones in the sides. Some of my others I did are not doing this. Should I have done something different, or perhaps it was too thick? I would appreciate some input from someone who has done white oak before. Thanks

[Richard Madison]

Have had similar results roughing and also turning to finished thickness in one session. Love the stuff, especially the end grain, but can't help and hope you get some good answers from someone who knows how.

[Dennis Ford]

I think that if you had turned it any thinner on the sides, you would not be able to turn it after drying. This will likely still be a problem once it is dry (your piece is quite a bit less than the 10% rule of thumb). A little thinner on the bottom than the sides should be an slight improvement. I have not used the DNA method, so can't speak to that. I have tried boiling white oak and that seemed to reduce cracking (distortion was not reduced). White oak is a difficult wood to dry without cracking and I suspect that no method is 100% effective to get a 15" round bowl.

If having the bowl be "out of round" is not a problem, turn it to ~1/4" thickness while wet and wrap that with brown paper. It will only take a few days to dry and cracks are much less likely.

[Dick Strauss]

Ron,
I don't know if any of this applies but here are a few hints...
-Get rid of the first five years of growth
-Round over the top edges of the bowl in the rough-out stage (sharp edges can cause cracks to form because the wood dries too fast at the corner)
-I've gone to a closed single or double bag for all of my pieces.
-How tall is your bottom tenon? Sometimes a tall tenon makes the wood that much stiffer in the bottom and doesn't allow the bottom to move per Dennis' suggestion.
-Make sure you go at least 1" beyond any cracks that were showing in the roughout stage.

Sometimes you can do everything right and it just isn't meant to be!

[Bernie Weishapl]

I have had problems with oak cracking to the point I don't like turning it. I have however found like Dick said if your round the rim over and get rid of the sharp corner that does help. Also I soak most of my bowls 3 to 5 days and that seems to help. Most woods can't soak up enough DNA in my opinion in 24 hrs. I wrap and cutting a open in the bowl side. I also stack mine near or on the floor with cooling racks.

[Ron Bontz]

Thanks for the suggestions. I just roughed out another 16" x 5" bowl. I'll try soaking it longer. I may try some anchor seal on one as well afterwards.

[Richard Madison]

Ron,
Please keep us posted on how it goes. Also if you completely anchorseal a roughout, I would be very interested in hearing about the result (in a year or so). If you manage to complete a 15" bowl without cracks you will have a real prize (IMHO). Good luck.

[Reed Gray]

Sealing the end grain may help. For securing the paper to the rim of the bowl, I prefer the 6 inch stretch plastic film that you use to wrap around boxes in a pallet to keep them from falling off. Available at any shipping place, or Office supply place. Do keep away from any wind, sun, or heat sources for a couple of weeks at least. If you have central heating, that can be a bit dry (humidity wise) and make it dry too fast. I have found leaving the inside of the bowl open to work much better than just plain bagging the bowl blanks.

robo hippy

[Steven Sprague]

Hi - I have roughed out 16 bowls this spring and have been trying the DNA procedure for the first time. These bowls range from 2" to 10" and are Maple, Birch, Walnut, mystery wood and my neighbors 12 year old White Oak tree they cut down.

I got the White Oak 1 day after cutting, sealed the logs with Anchor Seal and then roughed out 3 bowls. They were all about 6" or so.

Well, so far all my roughs are fine EXCEPT the 3 Whit Oaks. Every one of them has formed sizable cracks. Very disappointing, mostly as i would have loved to give my neighbors one of them as a memory of their tree.

[Reed Gray]

Seriously, try the plastic stretch wrap. Keeping the rim under a bit of compression makes a huge difference.

robo hippy

[Jeff Nicol]

Well I turn tons of Red and White oak and I don't soak anything in DNA at all, just more to deal with in the shop that may cause bad things to happen and smelly too. I turned a couple red oak bowls yesterday and they have some great grain and color in them. Red oak is easier to control the cracking on than white oak as the white oak is tighter grained and seems to grow much slower than the red. Like Reed said I make sure to seal the end grain with Anchor seal or wax, but I let the roughed out pieces air dry for an hour or so before applying the sealer. Then I put them in the plastic bags I get from the grocery store, they always seem to have a little hole in them someplace to let a little air in and out. Then I will leave them over night and take them out the next day. I dry out the bag, let the piece set out in the air for an hour or so then back in the bag and over night again. I do this until the bag has very little moisture condensed in it, then I may let it set for a week and bring it out again. Now I can leave in out in the air for more time, maybe even all day, then back in the bag over night or for a week or whatever. By now most of the moisture is out of the free grain and what is left if the trapped water in the closed grain. It takes a while for this to come out, but it will. After a month or so I may be able to take it out of the bag and set it on the shelf to dry the rest of the way. If the piece has lots of figure and wild grain it is prone to cracking in these areas so seal them best. I know it sounds like lots of messing around but in the end I have a nice rough out just waiting for its time to be finished. For me since I have 100's of bowls roughed out I can always find something to finish and I am never in a hurry to get something done. Like they say "Haste makes Waste"

Good luck,

Jeff

[charlie knighton]

i should have some white oak about ready to turn, it has been is cardboard barrels about 6 months, the cardboard barrels aging for red oak is not 100% but very good results, and you know when you take the blank out of the barrel weather you have firewood or a turning blank :eek:

[Bill Bolen]

I do much the same as Jeff. Seal the end grain inside and out with anchor seal then into a brown paper bag and forget it for 6 months. I don't use the dna simply because I'm not in any hurry to get the blanks ready for finish turning. Success rate is about 95% with only a few checked to the point of the burn pile. That was because I left the walls way to thick...Bill..