Boiled Bowl Experiment

by David Propst

There are many schools of thought on drying roughed turned green bowls. Some suggest doing nothing and letting them crack if they will (bad suggestion). Others suggest sealing with endgrain sealer (i.e. Anchorseal), wax, or wrapping in paper. A couple of years ago, boiling green bowls to stabilize them gained some popularity after Steven D. Russell published an article on this process. Plenty has been said here about boiling, but the results of a little experiment I did were interesting enough to share here.

The two holly bowls pictured below were both turned from each half of the same log in the same orientation on 7/1/02. After rough turning I decided to boil one and wax the other to compare how they dried. If I had thought of this before turning I would have turned them to roughly the same shape. However since they were within 1/8" of being equal in diameter and turned in the same orientation I figured it would be worthwhile. The bowl on the left had one-inch walls so I decided to boil that one since it would theoretically be more prone to cracking. The bowl on the right had 13/16" walls.

After boiling the bowl was removed from the water and immediately wrapped in several layers of newsprint and allowed to dry for one week. I have found if bowls are left to dry without this initial wrapping they tend to crack. I think this is because of the rapid evaporation from the hot bowl. After unwrapping the boiled bowl was placed in a shop cabinet next to the waxed bowl and forgotten for several months.

The bowl on the right was coated with Johnson's Paste Wax immediately after turning. As you can see, it distorted significantly more than the boiled bowl. It also developed greenish splotches over about 25% of the surface, which I assume is from mold in the wood.

Both bowls have not lost any weight since I first weighed them three weeks ago. Therefore I assume they are dry.

This small test is obviously not a scientific one, however the results do represent what I have seen with other boiled bowls versus waxed ones. I do not boil all bowls I turn. Fruitwoods like cherry really seem to benefit from boiling, as do other woods that tend to check easily. Highly figured crotch pieces are also good candidates for boiling. Other bowls are just too big for my pot!