determing pith how much?

[KEN RIEDEL]

I know that I should remove the pith when cutting blanks. BUT how do you determine how much is pith? Is it by color?

[Angelo Schembari]

For most hardwoods, the "pith" is the first few rings. In some woods, the ones with "true" pith, its soft and punky in the center. For most of my bowls, ive removed about an inch or so of the log center and none have split from the pith yet. On smaller logs (<10") ive just split them down the middle and turned away the pith for about 1/2".

Cheers,

Angelo

[Richard Allen]

Hi Ken

It all depends on stuff like the size of the log, species, time of year, what part of the tree the log came from, how you remove the pith.

Lets say it is silver maple 20" across in the winter, part of the trunk and you intend to remove the pith with a Chainsaw.

I would remove a 2" slice from the middle of the log. That would leave me a very good sized blank with little concern about a pith.

Part of that determination came from the Chainsaw. If I could be sure that the saw would cut a perfect line with respect to the pith I could reduce the slice to 1" (1" + the two Chainsaw kerfs). If I we going to rough the bowl right away I would make one cut along the pith and as I roughed the blank I would be sure to turn away any pith down to rings less that 1" across.

Roughing out a 20" blank is a lot of work and there is every reason to belive that I would not be able to get to all the sawn blanks before the pith/drying action would destroy the wood. So taking out a 2" slab eliminates my concern.

For a 8" log a single cut down the pith is my usual process. I will lose a portion of these blanks because I can't follow the pith well enough with the saw. But the level of effort and availability of 8" logs makes the single cut worth the effort.

Now if I had a prized piece of 8" wood I would make sure I roughed that blank out and sealed it up with anchor seal for a few months.

Thanks