I'm working on a frame-and-panel end for a stand-along window seat. For
the panels I had some 5/4 spalted maple and I intended to resaw it to
5/8" then clean it up to 1/2" thickness. The problem is that all the
boards bowed outwards very strongly after resawing; about 1/4" of bow in
the middle of a 19" cut.

My "post-incident analysis" (:-) is not reaching any firm conclusions
about why this happened. Does spalted wood tend towards having such
strong reactionary traits? Or, could there have been too much drift
compensation in my bandsaw fence that might lead to such a result?

CharlesJ
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================================================== ======================
Charles Jones | Works at HP, | email:
Hewlett-Packard | doesn't speak | ICQ: 29610755
Loveland, Colorado | for HP | AIM: LovelandCharles
USA | |Jabber:

Charles Jones wrote:

I'm working on a frame-and-panel end for a stand-along window seat. For
the panels I had some 5/4 spalted maple and I intended to resaw it to
5/8" then clean it up to 1/2" thickness. The problem is that all the
boards bowed outwards very strongly after resawing; about 1/4" of bow in
the middle of a 19" cut.

My "post-incident analysis" (:-) is not reaching any firm conclusions
about why this happened. Does spalted wood tend towards having such
strong reactionary traits? Or, could there have been too much drift
compensation in my bandsaw fence that might lead to such a result?

CharlesJ
--
================================================== ======================
Charles Jones | Works at HP, | email:
Hewlett-Packard | doesn't speak | ICQ: 29610755
Loveland, Colorado | for HP | AIM: LovelandCharles
USA | |Jabber:

Outside dry, inside less dry. Cut in half - one face dry, one wet -
resawn board cups. Let it sit for a day or two and see if it flattens
out.

(this one was discussed in an earlier thread on resawing problems)

charlie b

In article , says...
Outside dry, inside less dry. Cut in half - one face dry, one wet -
resawn board cups. Let it sit for a day or two and see if it flattens
out.

(this one was discussed in an earlier thread on resawing problems)

Yeah, I saw that one. Maybe I misread, but I was under the impression
in that case that the cupping showed up a short while *after* the
resawing took place. In my case the bowing took place during the cut
with the inside one trying to bind against the fence.

CharlesJ
--
================================================== ======================
Charles Jones | Works at HP, | email:
Hewlett-Packard | doesn't speak | ICQ: 29610755
Loveland, Colorado | for HP | AIM: LovelandCharles
USA | |Jabber:

The blade many not be tensioned enough, it may be dull, the feed may be too
fast and not steady, the bandsaw may be out of tune, the angle of the stock
to the blade may not be the angle at which the blade wants to cut. A lot of
times it is a combination of improper tension and running the board through
at the wrong angle. Mark a straight line down the top of a board. Freehand
the cut, staying on the line. You will see that the stock is usually at a
slight angle to the blade. Set your fence at that angle.

I also had that problem with my 14" Delta with a 6" riser. Needing to cut
an arc in 11" wide piece of mesquit, I finally decided to tune up my
bandsaw. It turns out the upper and lower wheels were not coplanar. That
puts a kink in the blade and tends to pull the blade to one side when
cutting, forming a concave cut. After I tuned it up, I put on a blade that
had given me this problem ( I also thought it was dull). I managed to make
the arc cut in the 11" wide stock with no problems. And the blade acted
like it was sharp. The tune up took care of my problem. See the "Band Saw
Handbook", by Mark Duginske for tuning up your bandsaw.

http://www.amazon.com/exec/obidos/tg...09532?v=glance

Preston

Preston
"Charles Jones" wrote in message
...
I'm working on a frame-and-panel end for a stand-along window seat. For
the panels I had some 5/4 spalted maple and I intended to resaw it to
5/8" then clean it up to 1/2" thickness. The problem is that all the
boards bowed outwards very strongly after resawing; about 1/4" of bow in
the middle of a 19" cut.

My "post-incident analysis" (:-) is not reaching any firm conclusions
about why this happened. Does spalted wood tend towards having such
strong reactionary traits? Or, could there have been too much drift
compensation in my bandsaw fence that might lead to such a result?

CharlesJ
--
================================================== ======================
Charles Jones | Works at HP, | email:
Hewlett-Packard | doesn't speak | ICQ: 29610755
Loveland, Colorado | for HP | AIM: LovelandCharles
USA | |Jabber:

OTOH, as previously noted, the description is the classic for too wet
inside. It's the reason for allowing a couple extra days between resaw and
surface. I take the pieces, put the fresh surfaces outside, clamp the
corners and set aside.

Spalted wood, if it is heavily spalted, has less capability, due to lignin
destruction, to stress into new shapes. Turners use this to make bowls of
crosscuts which would otherwise have rapidly split radially.

Now if one had a crown opposite where the other was coved, the blade
problems you mentioned would come into play.


"Preston Andreas" wrote in message
...
The blade many not be tensioned enough, it may be dull, the feed may be
too
fast and not steady, the bandsaw may be out of tune, the angle of the
stock
to the blade may not be the angle at which the blade wants to cut.

"Charles Jones" wrote in message
...
I'm working on a frame-and-panel end for a stand-along window seat. For
the panels I had some 5/4 spalted maple and I intended to resaw it to
5/8" then clean it up to 1/2" thickness. The problem is that all the
boards bowed outwards very strongly after resawing; about 1/4" of bow in
the middle of a 19" cut.

In article ,
says...
Now if one had a crown opposite where the other was coved, the blade
problems you mentioned would come into play.

Hmm, interesting. Either way I'm going to add the "Band Saw Handbook"
to my "to get" book list and do a thorough run through of the machine.

CharlesJ
--
================================================== ======================
Charles Jones | Works at HP, | email:
Hewlett-Packard | doesn't speak | ICQ: 29610755
Loveland, Colorado | for HP | AIM: LovelandCharles
USA | |Jabber: