Laminating strips into 18" dia 1/2 circle. Advise sought

[Pirate]

I need to laminate 72" long, 1/8" (?) thick x 1 1/2" strips of cypress, into a 18" dia semi circle, with one end having a 16" straight part. I want it to be thick enough to hang a light socket and shade from, and be able to leave a wire channel inside the laminations. I was thinking 3/4" - 1" thick.

It's part of a lamp to hold a light over a table used for jig saw puzzles.

Questions:
Cold lamination, or steam, bending? Both clamped around a form.
What thickness can I use with each method?
With cold laminating, how thick can I make the strips?
I would rather do cold, as I wouldn't have to rig up a steamer.
What glue is good to use?
I figured on making a form and cutting slots in the board the form is on, for getting clamps on.
How about a male and female forms? First bend around male form, then clamp female form on top of the lamination, with a strip of cork in between. Squeeze the lamination, between the 2 forms.

How do you figure spring back, after unclamping? I was thinking of maybe, lamination it in the shape of a question mark.

Sure would like to hear reccomendations to make this easier !! Thanks

[Woodjets]

I've done shorter strips 1/8" thick cold.
Titebond between the layers, clamped to a form.
I've done it with walnut, I have no idea how cypress would behave.

[handi]

Cypress will bend just fine as long as it is clear.

Your stack of laminations MUST add up to desired overall thickness. They need to start wider than the finish dimensions since the layers will NOT come out flush. You can joint and rip down the width, but the finished thickness is nearly impossible to change.

Knowing the overbend before hand is very difficult. More, thinner layers will spring back less than fewer, thicker layers.

The tighter the bend, the more spring back to expect generally.
Soaking the laminations in water and clamping them to the form without glue until they dry will largely pre-form the laminations making the final glue up easier.

Keep in mind too, the weight of the fixture that will be hanging from this piece will bend it a bit as well, so it will cancel out some of the spring back.

Plan on buying enough cypress to make two parts if this is your first big bent wood piece.

Check out my Skill Building page of my website for videos on both laminate bending and pre-bending soaked strips.

Ralph

[Pirate]

Thank for the replies.
I have plenty of Cypress in case I have to do it over.
I had thought of pre bending wet. Glad you mentioned it.

[Phil S.]

I made a handle for a firkin I made for my daughter out of 1/8" strips of ash. I "steamed" them by wetting them and wrapping them in aluminum foil and sticking them in the oven. Probably not going to work for your 72" pieces.

My pieces were bent on a ~9" diameter. I used a bending form I made out of plywood to the radius I wanted. Glued up a couple of pieces of 3/4" ply and cut the curve on a bandsaw. I drilled holes through the form big enough to fit the head of my bar clamps. That worked pretty well, but more clamps would have been better if I had drilled another hole in the form to accommodate them. I had 5 holes, about 45° apart, 180° around the edge of the form and that wasn't really enough. If I would have drilled one more big hole in the center of the curve I could have added another 4 clamps between the other 5 and would have ended up with a better job. I've never worked with cypress, but it seems an 18" curve would be pretty gentle and should work okay for cold bending.

You mention you have extra material so a dry run would be a good idea. You'll be able to see how they come together and make adjustments if necessary before you have glue on your pieces. As someone else mentioned let your material run a little long and wide so you can trim it to final dimension so when your laminations don't line up perfectly you have some room to fix it. DAMHIKT