Drying Protocol for Hollow Forms

[Craig Powers]

I'm trying to figure out how I should turn/dry hollow forms.
For open bowls, I'm turning to 10% thickness, sealing with anchorseal, and placing in paper bags.
I'm trying to adapt this to hollowforms. I've come up with several questions?
1. Should I turn them to 10% and let them dry and return months later.
2. Do you treat them different if pieces are short, rounded like a closed bowl or tall and thin like a vase?
3. If I turn green and dry, the return, how do I attach the piece to begin with? The tenon/chuck method seems a little difficult to remount. Especially after wood movement. Could runout at the end of a long piece could exceed the thickness of the piece?
4. Do I leave them attached to a faceplate or faceplate ring as they dry?
Does wood movement make the screws less effective? I've heard that screwing into endgrain isn't as effective compared to facegrain, all things equal.
5. Just turning green and finishing is an option, but some I'd like to finish when they're dry.
6. What about DNA or soap soak, etc.?
7. Piece with pith in or no pith.
8.Any suggested resources to read or watch?
Thanks for replies in advance.

[charlie knighton]

drying hollow forms

try to turn in one session, if have to leave overnight put in cardboard box with dry shavings, turn to desired thickness, 1/4 is very good, when you sand the piece you will be drying it

this works well with maple, black walnut, box elder, cherry,or woods that move but not that much, the moisture content can be 25% and below

woods such as apple will probably still warp and may split. woods such as cherry may already have splits and oak i will let you find out for yourself

nothing is 100%, i have heard of pieces done 6 months and then displayed at a high school gym for the weekend that split then

as we all are individuals each tree has been shaped by its enviroment which affects your end result

whats great is that each piece of the same tree mother nature has the abiltiy to surprize you :D

[Steve Schlumpf]

I turn my hollow forms to 10% thickness just like if it were a bowl. Soak the rough-out in DNA for a few hours and then wrap the outside of the form with a brown paper bag. Make sure all the wood is covered with the paper but make sure the opening to the hollow form is left open so air can circulate within. The idea of the paper is to slow down the drying of the exterior surface compared to the rate of the interior.

I usually wait for a couple of months before finish turning because I am in no rush.

As far as remounting the HF… I use a chuck/tenon when originally roughing the piece out. In the center of the tenon is the small divot created when the tailstock was used to support the work when first roughing out the form. No matter how much the wood moves – it seems that divot is still very close to center. To re-turn, I place the HF between the chuck – with jaws wide open and bring up the tailstock for support using that divot as center. You are using the chuck as a jam chuck to true up the tenon. I also reshape the exterior of the hollow form, especially the bottom area because of access, before mounting it by the tenon for final hollowing.

Hope that helps answer some of your questions. If you have more – ask! Someone here will have an answer!

[Bill Bulloch]

It helped me Steve. I had the same concerns. I have turned some hollow forms from dry wood, but was a little hesitant about green wood.

Craig, thanks for the question; Steve, thanks for the answer.

[Bernie Weishapl]

I do it both ways. I sometimes like Steve turn a piece leaving it witha a 10% or so thickness. Soak in DNA for a day or 2 or 3. Wrap and then cut a opening where the vase has been hollowed for air movement. Most of the time I turn green wood HF's from start to finish in one session removing from the lathe and putting the finish on it.