Est. 1998 — 27 years of woodworking knowledge
Piths and tool handles
Dan Clermont in Burnaby
>I was looking at an old chisel handle and noticed the pith was turned as well.
I thought this was a no-no yet it is there and hasn't split.
Is this legal?! I would have thought the pith would have split after some whacking.
Anybody out think this is the piths ;)
Cheers
Dan Clermont
RR ties
bill tindall
>i don't know so much about chisel handles but when we sawed RR ties they had to have the center of the tree in the tie. Supposedly it made the ties resist splitting; that is what I was told.
Re: RR ties
ThomD
>The better Japanese chisel handles are supposed to be turned out of pith centered pieces of wood. On a limb that small the pith is often nothing more than a useful insert centering tuyere. A piece of wood pith centered is completely ballanced for uneven effects of tangential and radial shrinkage. Not all Japanese chisels have heart centered wood, maybe because it isn't available in every species. Now when I want a file handle I just cut off a small fruitwood branch and fit the file to it.
The Japanese prefer their posts heart centered, and when they are planed to show the grain it is the same all around the post, which is a restfull appearance.
With posts like rail ties or 4x4s, they are more stable when heart centered. But moreso than that, they are horibly unstable when heart edged. If one got a piece of wood that was free of any pith, that might work too. But the pith down a surface is not durable, and these types of cut are usualy taken out of very small trees.
*Center cut* RR ties
Jim Reed @ Tallahassee
>I laugh when the I hear the Lowe's commercial for *center cut* lumber. They refer to it in reverence like a prime chunk of beef. Actually the center of the tree is the juvenile wood which is notorious for warp, twist, check and any other wood defect you can think of. It is useless for anything except RR ties and landscape timbers. Japanese carpenters probably used branches for their chisel handles because the other wood was too expensive. The mystique of balance and symmetry is just hooey and is not supported by fact. Just my $.02.
Re: *Center cut* RR ties
Bob Hackett(Mainely,Bob)
>I believe you hit it here Jim.The only solid wood that I`ve had any luck holding together with the heart in has been branch wood.
If you look at the examples of posts in Nakashima`s The Soul of a Tree,you can see that the softwood posts for temples and homes were made with relief cuts to control checking.
Most experienced turners can tell you thru experience that leaving the pith in on most hardwood is risky at best unless the pith is centered and the finished product is thin walled.
Mainely,Bob
Re: *Center cut* RR ties *LINK*
Pam Niedermayer - Austin, TX
>One of the side benefits of riving is getting rid of that pesky pith first thing.
Bob, you mention relief cuts to avoid checking. Can you tell if that's part of what mifuqwai is talking about at the link below? His English is just good enough to thoroughly confuse me.
Relief cuts
Bob Hackett(Mainely,Bob)
>On page 136 Nakashima has sketches of 3 different types of posts used in Japanese architecture,2 have cuts on them which he describes as such;"The sketches of the Menkawa and shibori posts show V-shaped cuts which run lengthwise down the back of the post.These result from a saw cut made in the green timber.During the curing process the cut opens up to a "V",eliminating the possibility of other cracks and the danger of splitting.The shi-ho-masa is cut into proper shape only after curing,so there is no "V" opening."
The one pic from Ebay seems to have a relief cut like Nakashima speaks of but who knows what the fellow selling the saw is trying to say.I know I read it afew times and only became more confused each time.
Mainely,Bob
Re: Relief cuts
Pam Niedermayer - Austin, TX
>Thanks, Bob, your explanation that the cut is a simple saw kerf that opens is all I needed to know. I guess that seller has modified his dozuki to take that cut.
Pam