Clamping help Please

[Charlie Ross]

Hi All, I’m making a 12 sided kitchen clock that I could use some advice on. The problem I’m having is; I’m not quite sure how to clamp something together with that many joints? I glued up the face made of 12 pie shaped pieces of walnut and maple cut at a 30 deg angle with a “ratchet strap clamp”. On the outside of the face I’m going to have a 12 sided molded ring. The molding is 1 1/4” wide x 1 1/2” deep with a rabbit on the inside for the face to sit in. I haven’t tried it yet, but it seems like trying to keep those 12 pieces together while putting tension on the “ratchet strap clamp” would be a good one for world’s funniest videos!
Appreciate any advice.
Thanks,

[Jerome Hanby]

I'd be tempted to go at it one section at a time. Maybe build a jig on top of some MDF and add 'bumpers" to clamp the pieces against. End up on the bottom or most inconspicuous piece and trim it to fit since there just has to be some cumulative error with all those angles. If you've ever seen the setup for making trusses for a gambrel roof where you basically turn a chunk of the floor into a temporary form for laying out and building each truss, that's the kind of thing I'm thinking of only reduced in size... I'd also come up with some way to reinforce each joint, a spline, a peg, something...

[Joe Angrisani]

Charlie.... Can you use clear packing tape and the old "roll it up" trick?

Lay out a long piece (or two, depending on size of the twelve blocks) of tape on your bench, sticky side up. Put your twelve pieces on the tape with their "outside" against the tape and the inter-block joints tight to each other. Put glue on all the bevels, and roll it up. The tape holds it all, keeping the joints tight, AND preventing sideways creep on the joints. Your flat assembly surface will help keep the front face of the assembly true.

[Andrew Pitonyak]

You could build a special jig to help, but I suppose that does not apply the pressure. This is the first thing that came to mind for me:

http://blokkz.com/

They are on special at the moment

http://www.blokkz.com/2-universal-clamping-blocks-ucb-with-2-neoprene-pads-new-years-special/

I saw something about them in Popular Woodworking

http://www.popularwoodworking.com/tools/tool-test-blokkz-universal-clamping-blocks
I think that there is a blog entry about them, but I did not see it with my quick searches.

You may be able to do something similar by creating some clamping cauls out of some wood cut at an angle.

[carl zietz]

When I get blood drawn I ask for the rubber tournequet they use and usually dispose of after each patient. tied around an odd shape it has given good glue up pressure when the standard clamps don't work.

[Jerome Hanby]

When I get blood drawn I ask for the rubber tournequet they use and usually dispose of after each patient. tied around an odd shape it has given good glue up pressure when the standard clamps don't work.

I saw a rolls of that on some woodworking supply site. I'm going to start stocking that in the shop, darn useful stuff!

[Todd Burch]

Rubber bands to get it started, then 6 windlasses.

[Charlie Ross]

Rubber bands to get it started, then 6 windlasses.

I tried to look it up, but couldn't find anything that made sense, What is a windlass?

[Gary Kman]

I would try to assemble 1/2 of the circle in a jig first. Repeat. Then joint the mating surface of each with a #7 plane for a perfect fit then glue the two halves.

[Michael Peet]

I would try to assemble 1/2 of the circle in a jig first. Repeat. Then joint the mating surface of each with a #7 plane for a perfect fit then glue the two halves.

I came here to say exactly this.

Mike

[Todd Burch]

I tried to look it up, but couldn't find anything that made sense, What is a windlass?

See this thread: http://www.sawmillcreek.org/showthread.php?16717-proper-method-to-tighten-up-chairs&highlight=windlass

Basically, you loop a string (cotton would be fine for your application) several times. Then, you put a short stick through loops and start twisting it. The string will get very tight. Wedge the stick near the frame itself and you got yourself a Spanish Windlass.

Todd

[Pat Barry]

There is a fellow who posts on the musical instruments page, name is Seth I believe. He makes drums made of many staves glued together. Ask him how he does it. I bet he would have a good idea for you. He has posted detailed, step by step instructions on how he makes the drums. Very interesting stuff.

[Pat Barry]

Fellows name is Seth Dolcourt. Check out this post http://www.sawmillcreek.org/showthread.php?168325-The-Poh-Bop

[Lee Schierer]

The trick to using a ratchet type clamp is to keep the strap centered on the sides of the work piece at all times and tension the clamp slowly. I used a ratchet type strap clamp to build this table. 220220 I carefully adjusted the strap once it was snug to get it exactly centered on the edges of each piece before I cranked up the pressure. I did it several times dry before I applied any glue just to make sure I could do it in the open working time of the glue.

[Keith Westfall]

Glue 2 pieces together 6 times. Then glue 2 (previously glued pieces) together again. until you get to where you only have 2 pieces (each half) to glue together, and then glue them together.

Way easier than all at once....

[Leo Graywacz]

Second the ratchet strap. I've used it many times. Most of the time if the joints are correct the strap will make things self center. If you put dowels in there you don't have to worry about that, just the flatness of the pc to pc joints relative to each other. For this I would make a board that is the same size as the assembled pcs and then put the pcs on the board with glue on there ends and then use some light clamps to hold everything to the flat surface. Then you can put the strap around the assembly and everything should pull together nicely.

I was making a wagon wheel and this is how I glued up the circle.

http://fototime.com/2BB6632EC5F80A8/orig.jpg

http://fototime.com/69CBA4CD274939D/orig.jpg

http://fototime.com/68EB5443167E193/orig.jpg

http://fototime.com/363539531D60E33/orig.jpg

And what the heck, while I'm at it here is the finished wheel.

http://fototime.com/DF7925A7503967E/orig.jpg

[Charlie Ross]

A lot of great advice to choose from!! I’m not sure what I’m going to do yet… I’ll have to figure it out this weekend.

Thank You much!!!

[Dennis Lopeman]

use a bicycle tube. you tie it around tight, then pump it up to add pressure.

[Dennis Lopeman]

I did look at the blokkz UCB - Universal Clamping Blocks (UCB)
http://www.blokkz.com/2-universal-clamping-blocks-ucb-with-2-neoprene-pads-new-years-special/
I'm still watching the video: http://www.youtube.com/watch?v=LOa1FFeZycU&feature=related

PRETTY darn COOL!! Simple engineering at it best! Just remembering my physics like the ball and socket and this idea is similar. A circle can apply the force in any direction along it circumference. So can a ball in a socket. And the strategically placed holes allow these blokkz to be used in lots of other places, too!!!

i likey

[Charlie Ross]

Second the ratchet strap. I've used it many times. Most of the time if the joints are correct the strap will make things self center. If you put dowels in there you don't have to worry about that, just the flatness of the pc to pc joints relative to each other. For this I would make a board that is the same size as the assembled pcs and then put the pcs on the board with glue on there ends and then use some light clamps to hold everything to the flat surface. Then you can put the strap around the assembly and everything should pull together nicely.

I was making a wagon wheel and this is how I glued up the circle.

And what the heck, while I'm at it here is the finished wheel.



Leo, That's great, That is a fine piece of woodworking!!!
I'm going to give the ratchet strap a try the way you mentioned. The diameter of my looks to be smaller, but maybe if I clamp it down like you mentioned it might work for me.
Thanks

[Mike Goetzke]

I have used these for multi-sided glue-ups:

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/merle_clamp.html

You can buy additional jaw inserts.


Mike

[Keith Westfall]

You can go to a sports store and buy 10 feet of surgical tubing. It stretches TIGHT and easily ties off by tucking the end under one of the other wraps.