Steam bending ?

[Rick Thom]

I am planning to make some circular hoops out of air dried ash. The hoops will be 28" diameter, 1 1/2" wide and 3/8" thick. The joint where the ends meet will have a 5" overlap and be lapped to form the uniform width and thickness. I plan to use 2 part epoxy to secure that joint together. I have made the bending form in several parts .. a continuous round outer form and a continuous inner form made with several pieces so I can clamp the inner and outer together with the steamed ash between them.
How long should the ash be left in the form to ensure it keeps the circular shape?
Am I better to glue the joint when I put the steamed hoop in the form, or would it be better to glue it after when I take it out of the frame? The epoxy http://www.leevalley.com/wood/page.aspx?c=1&p=20012&cat=1,110,42965&ap=1isn't water submersible and I am presuming the amount of moisture in the steamed wood won't seriously affect it.
I haven't tried anything like this before so it's new to me.

[David DeCristoforo]

"Best" would be to bend the ash hoop into a "spiral" so that there is at least six inches of overlap above and beyond what you need for the joint. Then let the wood dry before you cut your scarf joint. If you make the scarf before you bend the wood, you will never know how it will align after the wood has been steamed and dried again. Bending ash is fun. Steam it enough and it will turn into a "noodle!

[Rick Thom]

David, i was thinking, perhaps incorrectly, that after it was steamed I could manhandle it into the form, apply the epoxy to the joint and clamp the 2 forms together with the precut joint aligned properly. Now that I write it, sounds like a lot of steps when that ash dries in a big hurry and the epoxy sets up in a very few minutes as well. Hmm. maybe i will go with your suggestion.
Do you have any sense of how long the ash needs to be in the forms to retain it's memory for the new shape?

[David DeCristoforo]

I would leave the piece on the form until it's pretty much dried. Even then it might want to spring back a bit. Steam bending is fun but it's not completely predictable.

[Rick Thom]

David, in case you are curious what these are... they are reproductions of hoops for a 'hoop and stick' children's game popular in the late 19th century commissioned by a heritage museum. These will be used for demonstration purposes and I am told they are as popular with children now as they were originally. Many years later, they reappeared in a slightly different form as hoola hoops.
Thanks for your advice.

[Jim Creech]

Rick,
Drying time will depend somewhat on whether you are using "wet" or "dry" steam and how long the steaming time is. Assuming you are using wet steam and "overcook" you may want to leave it in the jig a couple of days. The visual I have on your jig suggests that airflow will be restricted thus increasing drying time. And yes, there will be some spring back but as your hoops are only 3/8" thick this is a minor issue.
Good Luck!