Wood bending

[Allen Grimes]

Can 3"x3" white oak be bent to a 1' diameter? If not what is the smallest diameter that it can be bent to?

[Lee DeRaud]

Resawn into 1/16" strips, bent, and glued up...maybe.

As a solid piece? Not happening, no way, no how. Hint: the outside of the curve will be almost 5" longer than the inside of the curve. A 10' diameter might work...was that "1' diameter" a typo?

[Allen Grimes]

no it wasnt a typo but what you said helped me enough. thanks, I know what to do now.

[Rob Russell]

You would not want to bend the strips, let them dry and then glue them up - the individual strips will take different sets and the lamination will have gaps between the layers. You'd want to bend and laminate all of the strips in one step.

I remember reading an article on this in FWW - did a quick search on their website and check of my FWW magazine archive. Issue #115 from Nov/Dec 1995 has an article on bent laminations, including how thick to make your strips, glue recommendations, form tips etc. If you don't have that issue, I'd suggest ordering the back issue from FWW - I feel the $10 would be well spent. A quick scan of the article reminded me that there's a lot to doing bent laminations and that article has a lot of (what seems like) good advice.

Rob

[Richard Wolf]

That is a very tight bend. Lee and Rob have covered bending, but even using 1/16 strips and lamination gluing you will have a difficult time.
I think if possible, gluing up some flat sections and cutting the piece out on a band saw may give you better results. The more pieces you use the less grain runout on the edge.

Richard

[Doug Shepard]

I haven't done white oak, but I've done cherry bent laminations down to a 4" radius - 2" shorter than what you're after. It's do-able, but you're going to want 1/16" or even thinner layers.


You would not want to bend the strips, let them dry and then glue them up - the individual strips will take different sets and the lamination will have gaps between the layers. You'd want to bend and laminate all of the strips in one step.....


I'd echo Rob's comments with a slight twist. I stuck my whole laminate stack into hot water separated by 1/8 spacers and let the whole thing soak for about 30 minutes. Then pulled it out, wiped everything as dry as possible, and clamped the whole thing between male/female bending forms for about a week. Then I pulled them out of the form, applied glue, and stuck them back in the forms and clamped up. As long as you keep all the pieces in the same order, when you get ready to start spreading glue on them, the pieces already have quite a bit of the curve bent into them with the right radius from layer to layer. Those pieces get real slippery with glue on them and trying to wrestle them all into the forms and clamp those really small radii starting from flat is a real PITA. With the first couple of tries I did without the soaking step I had a problem getting all the gaps to close up between layers, and was finally able to get rid of them with the added soaking and dry clamping.

[Dave Richards]

I'm dredging this up from several pages back. Curious about your application for these rings.

Mast hoops have been made for years by steaming and wrapping strips of wood around a form. Then the ends are rivetted together with a copper rivet.

Some modern folks with wrapped the steamed strip and clamp it. When it has cooled and dried they epoxy the whole thing.

A mast hoop won't have a 3"cross section but they are frequently even smaller in diameter. Perhaps you could do something along those lines though for what you want to make.