Bending a maple top over an arm contour

[bruce bennett]

I used a 3/4" thick piece of plywood 21" X 8" as a gluing caul.
and I cut the area where the bend/arm scarf was to be in 1" wide strips on the parallel with the direction of the bend.
then I glued all of that to a same sized piece of short knapp stiff carpet, so that all the strips would bend but would still be attached to each other and the main flat portion of the caul as well..

I used a capped 3" diameter copper pipe about 12" long with a propane torch blowing inside it as a bending iron,
I wetted my top down thoroughly, and bent the top on the hot pipe to get the bend started good..checking the fit as i went, then once it was about 1/4" from touching all the way down the scarf.
I glued it up,... I put the "flexible" caul on it carpet side against the top, and added 4 twin screw clamps on the flat portion.. and added two 5" "C" clamps on each 1" strip (one on each side of the arm scarf) until the top was tight to the back.

it was very simple and easy to do, and took about 45 minutes overall. and i did not rout the underside of the top at all.
I did thin the top to 15/64" (about 6mm) thick just to get every advantage I could.

 

[Skyjerk]

I used a 3/4" thick piece of plywood 21" X 8" as a gluing caul.
and I cut the area where the bend/arm scarf was to be in 1" wide strips on the parallel with the direction of the bend.
then I glued all of that to a same sized piece of short knapp stiff carpet, so that all the strips would bend but would still be attached to each other and the main flat portion of the caul as well..

I used a capped 3" diameter copper pipe about 12" long with a propane torch blowing inside it as a bending iron,
I wetted my top down thoroughly, and bent the top on the hot pipe to get the bend started good..checking the fit as i went, then once it was about 1/4" from touching all the way down the scarf.
I glued it up,... I put the "flexible" caul on it carpet side against the top, and added 4 twin screw clamps on the flat portion.. and added two 5" "C" clamps on each 1" strip (one on each side of the arm scarf) until the top was tight to the back.

it was very simple and easy to do, and took about 45 minutes overall. and i did not rout the underside of the top at all.
I did thin the top to 15/64" (about 6mm) thick just to get every advantage I could.[/quote]


That's the exact kind of bend I'm looking to do. Thanks for the post Bruce. :-)

 

[j.six]

Are those the only 3 things I need?

Yep!

 

[Barnaby]

That's the exact kind of bend I'm looking to do. Thanks for the post Bruce.

That was it! The post I was thinking of. Thanks, Bruce!

 

[tonedragon]

Try soaking the maple then bend over a template. Once dry glue onto body.

 

[Skyjerk]

Actually I'm going to use several of the suggested methods in conjunction

I'm going to go ahead and route some small channels underneath. Originally I had not wanted to but I've been convinced this is a solid approach.

I'm also going to moisten and heat it and pre-bend it as well as I can.

Finally, I maxxed my CC and bought the vacuum pump system that Sully recommended
and will use that to glue that top in place nice and tight.

If Sully loves it right in the face as he says, I'm sure I'm going to dig it

Since I went and spent the dough I expect I'll be using the vacuum system to clamp all my tops from now on

I didnt have enough dough to get the clamping pods they have as well, but I will get them down the road when I can afford it. They are used with the pump as a vacuum clamping setup for holding stuff down on tables and whatnot instead of having to clamp things to your bench to hold them while routing, etc...