hewing bowl

[Eric Erb]

so not ever having done this before, but having a log and an axe, I set about to hew a bowl from said log. it's a fair bit more work than expected. though what has me quite chagrined is the cracks developing. I know why, but i don't know how to either prevent or work with so they don't occur. i've seen wooden bowls without cracks so i know there is a way, i just don't know what that is.

your comments concerns and suggestions are most welcome.280825280826

[Jessica Pierce-LaRose]

I'm sure someone will chime in with some info, but if you don't get any help here, try the turning forum. You may be making it via an entirely different means, but it appears you're trying to end up with a similar final product to a turned bowl. Those guys will have a lot of experience working with green wood and these forms, and will know the questions to ask and the pointers to help you. They might not have pointers on the chopping, but my understanding is they deal with the peculiarities of wood movement quite regularly.

[george wilson]

Some soak green wood in polyetheleyne glycol based products that displace the water. I do not use green wood. Joshua's advice about the turner's forum is good.

If my wood is 100 years old,I will smile upon it.

[Sean Hughto]

I've never hewn a bowl, but I've turned lots of them. Green wood is a blessing and a curse. It is nice to work, but it will crack as it dries. The subject of preventing cracks could/has filled chapters in books. I'm glad to answer specific questions, but here's some basics:

- different types of wood have different propensities to crack in terms of number of checks and speed of checking

- wood cracks from the pith, so never include the pith in your work or blank

- wood begins to dry, and therefore to crack, as soon as its cut

- slowing the drying, making the drying even across the wood, displacing the water, and relieving the stresses are all strategies for avoiding cracks

- turners will often rough turn a bowl to something like three times its expected finished thickness and treat that rough with anchor seal or simply put it in a few layers of paper grocery bags and set it aside to slowly dry over several months after which the bowl is re-turned to a final shape and thickness

- some use alcohol baths to displace the water but I've never done this and can't speak from experience on the subject

Hope some of this helps.

[Steve Friedman]

Sometimes cracking is inevitable, but the log starts drying out very quickly as you start hewing. Typically, the log will also dry out unevenly, since the pith side has so much area exposed to the air. My suggestions:

1. Try to control the rate of evaporation. One of the easiest way to do that is to put the log into a plastic garbage bag when you're not working on it. Even after it's done, you can keep it in the bag and open it for an hour a day to let the water evaporate slowly. Pentacryl also works, but you would have to reapply it after every work session. Gets expensive on a large bowl.

2. Pick logs with straight grain.

3. I always remove the pith as soon as I start working.

4. Make sure the log is well supported and that any axe work is with the grain (or at a bias) to avoid adding stress to the wood.

5. Remember that small cracks can be repaired with glue or epoxy.

Hope that helps.

Steve

[Sean Hughto]

A friend in a far away city had a tree come down in their yard and I offered to turn a bowl for them if they sent me a blank. Here was my directions to them for what it may be worth as far as giving insights into bowl making and crack avoidance:
http://farm3.staticflickr.com/2223/2290545828_5e0bb61a2f_b.jpg

[Eric Erb]

wow great ideas guys thanks. i'll have to look at the turner's forum, i've not gone beyond this one yet!

[Dennis Ford]

In addition to the good advise you have already received: If you start with green wood, keep it wet until you have finished the roughing out (at that time it will be thinner and slightly flexible, which should help while drying). Slow the drying rate with your choice of methods (brown paper wrapping is a simple method).