cracking

Re: cracking

John Lucas

>Marc

Find new logs. If the ones you have are 3 years old they already have the splits in them. The only solution I know other than using different logs is to turn the outside. Then look very hard for cracks and fill them with epoxy or CA glue. Then go back and turn the inside. For safety's sake wrap the outside of the piece with nylon strapping tape. Other than that which is pretty extreme I would suggest learning more about harvesting and turning green wood.

Seasoned logs like you have are better for spindle turning. I cut up some 2 year old Cherry last night and made and made 4 legs for a project.

Re: cracking

Brad Vietje

>Marc,

A couple of thoughts come to mind... First, I'd suggest "Turning Green Wood" by Michael O'Donnell; then:

1. Maybe the logs are already cracked, and you can't see them ? Cutting into the wood may only reveal the cracks.

2. As you remove wood, the wood is releasing stresses in the log ==> cracks. It usually does not work very well to season logs whole; it usually works better to split the log along the pith, and allow the halves to shrink radially.

You might look at the end of a log, and saw off a thin slice, looking for any cracks in the end grain. Then, split the entire log along the major cracks. If you are hoping to turn something using the whole diameter of the log, you will intrduce another set of difficulties.

3. If a 6" log is sitting around for 3 years, its almost half way seasoned -- the wood still has a need to lose moisture, and shrink as it is exposed to air.

4. Spalted wood is tougher to turn than fresh wood. Not tougher wood, but harder to get the desired results. After splitting the wood for additional seasoning (and sealing the ends), you might practice on more mundane wood you can get your hands on.

5. Find an experienced turner near you, or better yet, an AAW chapter, and ask lots of questions. Most turners are eager to help newcommers to the sport.

Safe Spinning,

Brad Vietje

Thetford, VT

Re: cracking

Richard Allen

>Hi Marc

Are you turning the wood from the side of the log or from a slice of the log (endgrain vs sidegrain)?

If you are turning endgrain bowls (from a slice of the log) then the stresses you are reliving will result in cracks as you turn the wood.

If it is sidegrain (from the side of the log) the cracks were likely already in the piece you are turning. You can repair the cracks but it is likely more worth your effort to start with sound stock.

Re: cracking

Rick in Colgate

>I've tried turning lots of maple that was already end checked. I cut away the checking and tried turning bowls and they cracked anyway. I believe those cracks and checks extend further into the log than we can actually see. Had the same thing happen with some black walnut that I was given that had seasoned for 5 years. One bowl actually flew apart on the lathe.

Re: cracking

Brad Vietje

>In Rick's case, he might have been better off to rough turn the wood right away, and then season it for 6 months or so. After drying and warping, the bowl can be re-mounted, and turned round again. The trick is to dry the wood very slowly, by waxing, bagging, or boxing it.

Safe Spinning,

Brad Vietje

Thetford, VT

Re: cracking

Bill Hale, Woodspinner

>Marc

Tell us more of what you are doing.

It sounds like you are trying to turn the wood cross grain with the pith in the center. If this be the case in almost every case you loose.

The stress inside the wood will cause a crack. Cut the pieces in half with the grain and use the two halfs.

If the wood holds no special meaning to you it will make good firewood.

6 in. Dia makes very little bowls. OK for pens or small decorations etc.

Good turning and be safe

Bill