Steam Bending QSWO

[stevem]

i have to bend some qswo to create some pieces 1 1/2 by 1 1/2 with a 9 1/2 inch radius. My stock is dressed to 3/4 by 1 1/2 and a little over 4 feet long. The bent pieces will be laminated to create the 1 1/2 material

I will be bending the first piece around a form followed by the second piece wrapped over the first and glueing them together at some point.

I assume that hot wet wood will not glue properly, am i correct? and if so when should they be glued up?

I have the Lee Valley bending setup and a heavy duty form and drying rack as per their instruction manual plus a kettle, hotplate and steam chamber of abs pipe.

Any hints, suggestions?

[WCraig]

That seems like a tight radius for a fairly heavy finished piece. Whatcha making?

I think the pieces may deform a bit--the outside face may not be flat after the bend. If so, this will interfere with gluing up the finished lamination.

Random thoughts:
-make a few extra blanks in case one (some) break.
-air-dried, riven stock has the best chance of success.
-use a strap on the outside of the piece being bent. Attach a big handle to the strap to help pull it around.
-get some extra clamps; and then a few more!

Is there some reason you don't want to go with a lamination of many thinner pieces?

Craig

[Pete in Welland]

If I read you right there are only 2 laminations in each. I don't think they will hold that shape for very long, plus that's a pretty tight radius. I would use 1/2" stock in 3 laminations. You have to leave the pieces in the jig until they are completely cold and then glue them. Also take into account there will be a certain amount of spring back when they are released so always over bend a slight amount. You will also find it a lot easier to bend green unseasoned wood than dry straight from the box store.
Also it is usual to use steam bending to eliminate laminating so maybe some re-thinking is necessary. Just what is it you building? Give us some input

[stevem]

thx for the input guys
the lumber is qswo air dried to around 12 percent, not kiln dried and definitely not from a box store!! It is 1 1/8 in the rough and cleaned up to about 7/8 to 3/4 about 4 ft long and 1 1/2 wide so bending 1 1/2 square material is out of the question

the pieces i'm making are u-shaped bases for arts and crafts style dining chairs, never seen a chair like it but thats what the client wants and its his wood

[OttawaP]

Maybe post a pic of the chair and alternatives may be suggested other than a tricky bend. Pretty tough to beat a simple lamination and good 'ol epoxy.

[adam_kropinski]

Steve,

I've steam bend a number of pieces to tighter radii than 9" and they were 2" square cherry. I would use 1 piece vice 2 pieces laminated together. There will be some distortion in the bending process and it is unlikely that you would get the two pieces together with acceptable results. Give a test piece a try. It will need a couple of hours (dont over steam) to get the lignin bonds to break.

good luck

Adam