Spalted blanks question?

[Fred LeBail]

I am trying to get some bowl blanks roughed turned so I will have some to Finish turn when I need them. I never seem to have them except at Christmas time.
My question is this,In Spalted wood should I leave more than the usual 10% of blank diameter for returning or should it be the same?
Also any other hints about spalted wood will help.
Thanks in advance,
Fred

[Barbara Gill]

I don't rough turned spalted bowls any thicker than I would non-spalted.

[Fred LeBail]

Barbara, is the drying time the same, 4-6 months?
Fred

[Dave Smith]

Turn spalted bowls the same thickness as other wood. The most important thing is to start your finishing cutting techniques before your roughed out bowl is down to size. Spalted wood is just rotten wood and it is prone to having the fibers pulled out instead of cutting cleanly. If you think you will clean up the tear out after the bowl is dry you may be disappointed. Taking more time shaping roughed out spalted bowls makes for an easier time getting a good smooth finished bowl.

As you might expect I use the alcohol drying process for spalted bowls and just about everything else I turn. They dry at the same rate or a little faster than solid timber bowls.

Dave Smith

Getting close to bed time in Longview, WA.

[Steve Inniss]

Fred,
A couple of things I would add:
Spalted Maple does dry faster - the structure has broken down and doesn't loose moisture as much just from end grain, but throughout.
Use sharp tools to reduce tear-out.
Monitor your sanding frequently- some areas are much softer and will sand away very fast, especially the rim. -Steve

[Barbara Gill]

Actually it depends upon the type of wood and the degree of spalting. For instance, nicely spalted hard maple from Maine does not dry any faster than that without.

[Matthew Clarke]

Hi Fred,

Once wood gets below 30% moisture content, the fungus that causes the spalting ceases to affect the wood. So, all that need to happen is to dry the bowl as you normally would. I rough turn all my bowls to about 10% thickness-as Dave Smith suggests.

After the bowl has dried however, because the wood fibers have already rotted, they do tend to tear-out. Use a very sharp gouge to give you a nice shearing cut. That should take care of most of the problem. If that doesn't take care of all of the tear-out, do some power sanding on the spots with any remaining tear-out. Stop the lathe and slow the speed of the power sander. Your paper will cut more efficiently and stay cooler (it won't burnish the wood). As an added bonus, your dust collection will also be more efficient because the dust particles won't be kicked of the lathe with the such great velocity.You will notice that almost all of the tear-out will occur on the endgrain sides. Just be patient and you will end up having to do much less sanding.

Best of Luck,

Matt Clarke

[thomas prevost]

Not much of a turner but sell a lot of spalted wood. Remember any rotted portions will shrink more than the hard sections. You need to account for this. For saw boards, we always cut at about 5/4 so when dry there is enough in the low rotted areas to plane to 3/4 inch.