roughing hollow forms

[Harvey M. Taylor]

Question: when roughing wet hollow forms, do you hollow to thick walls, put it away to dry, then re-turn to finished size? in a fog in Ft. Worth Tx. max

[Dale Gillaspy]

That is usually the formula. You have to leave enough thickness that you can turn the warpage out and return in to round, but thin enough to allow it to dry evenly. Then there are several methods of drying, including paper bags and old shavings. Of course, you can always turn it to finish thickness wet, and allow the warpage to be a part of the finished product.

[Steve Schlumpf]

Max, you can use the 10% rule (or a little less) just like when roughing out bowls. The one thing I have found that makes a huge difference is to make sure that the walls are of even thickness. If you leave one part thicker, it will take longer for that portion to dry and the form will most likely crack in the process. Good luck!

[Bill Bukovec]

Max, I use the 10% rule. Then I seal the blank, put it (and some of its shavings) into a paper grocery bag. Then I tape the top of the bag shut. I usually leave it in the bag a year before final turning. Bill

[Dennis Ford]

The 10% rule works for pretty much any wood. Drying time is very variable, mostly dependent on temperature and humidity but wood variety and how it is stored also come into play.

[Bruce Lundgren]

I attended Steve Sinner's demo at the AAW in Tampa. He had demos to rough-out and finish hollowforms. As I recall, he followed the 10% rule paying particular attention to the bottom since leaving it thicker invites cracking. I was also surprised at how small his tenon was at the base which he does on purpose..again to avoid cracking. I think he anchor seals the base and around the opening and said he hangs them up to dry ( I would guess the drying method depends on which part of the country you live in). I've not done any yet but learned a lot. I'm sure others here can add much more help than I can.
Bruce

[Harvey M. Taylor]

I admit, I am spoiled. Here in Tx. where mesquite is fairly plentiful and stable, I wondered about letting it dry before finish turning it. No other known wood is stable like mesquite. However. if I have to I will let it dry before finish turn it. Thanks for all the responses, Max

[Joe Meirhaeghe]

I attended Steve Sinner's demo at the AAW in Tampa. He had demos to rough-out and finish hollowforms. As I recall, he followed the 10% rule paying particular attention to the bottom since leaving it thicker invites cracking. I was also surprised at how small his tenon was at the base which he does on purpose..again to avoid cracking. I think he anchor seals the base and around the opening and said he hangs them up to dry ( I would guess the drying method depends on which part of the country you live in). I've not done any yet but learned a lot. I'm sure others here can add much more help than I can.
Bruce


Bruce. I've work with Steve Sinner in his studio a couple of days a week for about 5 1/2 yrs now. We do a lot of collaborative piece's together. I have also assisted him in teaching a class at Marc Adams school of wood working last year.
That said neither Steve or I use the 10 % rule. We rough turn piece's any where from about 5/16 " inchs to maybe 7/16 " inch thick. Depending on wood species & quality then overall size. A piece 6" tall or less with no knots would be roughed to about 5/16" thick. A piece say 20" tall would be roughed out to about 3/8" to 7/16" thick. That's a long way from 10 %.
I must also mention that all our pieces are end grain hollowed, not side or long grain. The woods we use usually don't move a lot during the drying. So we still have enough wood to re turn to a final thickness usually anywhere from 1/8" to 3/16" depending on the overall size of the piece.
These are all fairly general examples as every piece is different.

[Bruce Lundgren]

Thanks for the clarification, Joe. I stand corrected. I seem to recall that someone asked that question at the demo but I'm mistaken.Steve mentioned your collaboration. The work is spectacular as everyone could see in the gallery. Museum quality pieces especially in the finish!