Knowledge You Can Build On — Est. 1998
BOWL WARPING
Jim King
>I am having trouble with bowls warping in the sanding stage. I have made several salad bowls about 1/8 inch thick trying to get the weight and feel of a glass bowl and each one has warped during sanding. Normally have made the bowls at least i/4 inch thick and never had trouble. Any ideas or am I just trying to do something foolish ?
Re: BOWL WARPING
Dick Hines
>You may be sanding to fast and couseing the bowl to heat up. Try slowing the lathe speed some.
Re: BOWL WARPING
Russ Fairfield
>Thin wall thickness can be a problem because of wood movement. The turning and sanding will generate heat, and this will lower the moisture content of thin wood very quickly. Lower moisture content equates to wood movement, and we call that warp. It is always a good idea to use a fine mist of water to prevent thin wood from over-drying as we turn and sand it.
Always allow very thin wood to return to room temperature and equilibrium moisture content before judging the amount of warp. It may not be as bad as it first appears to be.
And, there is always the problem that the internal wood had not dried to equilibrium moisture content before we start turning it to its final thinness. In that case, the wood is just drying to equilibrium and moving to where it wants to go, and there is nothing we can do about it.
There is a solution of sorts. You can add or remove warp in thin wood by heating it in the microwave, moving it into a better form while it is hot, and holding it there until it cools.
Re: BOWL WARPING
Jim King
>The peices do get very warm and so do my fingers. I thought this was probably the problem. Very thin peices are a new thing to me.
Thanks
Re: BOWL WARPING
Jim King
>Russ: Thanks, I will try this also.
Re: BOWL WARPING
Barry Turner
>What's the deal with 1/8" thick walls for a salad bowl? A bit too thin for something that is intended to be used. Why do something that causes you a problem, if it's not better? Save the 1/8" thick walls for decorative and art objects.
Re: BOWL WARPING
Jim King
>People like them and thin and super shiny sells here. The less it weighs the more they pay.
Re: BOWL WARPING
Barry Turner
>Well, we can't argue with that can we?
