Cracking????????????

dicklaxt1 · 03-23-2002, 04:43 PM

I have bee running around to different sites and looking at lathe turnings here and there..........It seems to me there is a high probaility of checking/cracking on those very delicate bowl/vase walls but I haven't seen any...............whats the secret to steming this natural process,got to be another trick or is it magic?

dick

**Isaac Hart** · 03-23-2002, 05:23 PM

First, they might be using dry wood, but dry wood is only good for thicker pieces. If you try to turn dry wood too thinly, dry wood wont have very much strength, and will crumble(usually on the lathe). Most likely they are using green wood. By turning green wood your finished product is much stronger. Because of this, you can turn green wood much thinner than dry wood, even to he point of translucence (my favorite kind of turning!). The advantage of turning the walls so thin, is the wood can distort more readily, so you dont put as much stress on the wood as it shrinks. The only problem is that the wood will distort, sometimes very heavily. I have several oval turnings because of this, but it can actually be attractive. You can dry thicker pieces without cracking by drying the wood VERY slowly (from several weeks to several months. Doing this, you want to roughly turn the wood (I like 1/8" to 1/4" of the final thickness)and then when the wood is dry, put it back on the lathe and finish it. There are also other methods such as PEG (poly ethelyne glycol), but I dont have any experience with those.

Isaac

**Lou_williams** · 03-24-2002, 02:36 AM

When you turn green wood you want to make thin walls. That way there won't be much checking or craking because you have the same amount of mosture leaving from both sides. Being thin the wood does not have the chance to have major mosture differences between different parts of the wood.

But as was pointed out there is a great chance of movement that will change the shape of the piece. Many people count on this to make the items more interesting.