Clamping odd angles

[Paul F Mills]

I am working on a chair project and the angles are not 45deg. I tried the painters tape glued to painters tape with the cutoffs but it did not hold. I them tried clamping the cutoffs to the members to then clamping against across the assembled piece. It worked ok but not great. I have seen people use the old wooden clamps as blocks to clamp against so I may try that next, if I can find mine (never actually used them after dad gave them to me). I have the Rockler and Woodpecker 45deg clamp blocks, but they will not really help here. Any suggestions?

[Brian Tymchak]

You can glue blocks to your work to provide something for clamps to grab on to. Then you pare off the blocks with chisels, block plane, etc.

[Keith Westfall]

Depending on how much and how long, but black electrical tape pulls tighter than you would imagine - just stretch it good while you wrap it on...

[Gustav Gabor]

If a large amount of force isn't required to close the joints, I've found regular old hot melt glue with mdf blocks to work well.
It's fairly easy to pop the mdf blocks off, but be sure to remove all traces of the hot melt glue, as it can get into the pores of the wood.
The glue can cause problems with staining and finishing if not removed completely.

[andy bessette]

Sometimes you have to get creative with clamp placement.

https://i.postimg.cc/XvxnyyHf/surf-4.jpg (https://postimages.org/)

[Frederick Skelly]

Paul, I cant quite visualize your glue up. Could you make use of surgical tubing in some way.? LINK (https://www.amazon.com/Natural-Speargun-Slingshot-Catapult-Surgical/dp/B07W414S2B/ref=sr_1_1_sspa?crid=11F9CD8X6SNRE&dchild=1&keywords=surgical+tubing&qid=1588069906&sprefix=Surgical+tubing%2Caps%2C238&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyR0lNUzlZTUVNSjNRJ mVuY3J5cHRlZElkPUEwNDA3MjI4MVVKVE43OUxXWVBBOCZlbmN yeXB0ZWRBZElkPUEwMjI4OTcwMjJUM1NPMDBLNEQwNiZ3aWRnZ XROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05 vdExvZ0NsaWNrPXRydWU=) This stuff helped with a chair I needed to repair. It will let you cover a lot of oddball angles and it's pretty strong.

[John Jardin]

Paul,

I am in the process of glueing up bases for a pair of serpentine dressers with mitered and scrolled, 45 degree legs.
An outstanding article by Steve Latta, FWW #204 May/June 2009 "When Clamps Fall Short" has been very helpful.
There are numerous ideas including the use of packing tape which might help you in solving your problem.

John J

[Kevin Jenness]

A picture would help define the problem.

It sounds like you are trying to clamp a curved surface using clamped-on bandsawn offcuts, which is a valid approach. You may improve your chances by gluing sandpaper to the offcut to prevent sliding, or tacking the offcut with hot melt glue or yellow glue with brown paper between the parts. Sometimes it helps to add a flange to the offcut and clamp it to the adjacent surface, again with added sandpaper. Directing the clamp force at right angles to the glueline works best, so saw a ledge in the clamping block at the correct angle and centered on the joint.

Stretchy stuff can work wonders. Stretch wrap is something I keep on hand.

[glenn bradley]

Another vote for surgical tubing for odd-ball glue ups. Chairs are not that odd-ball. Watch some Fine Woodworking videos on chair making for examples. Strap clamps can come in handy for those of us who don't make enough chairs to qualify the time for making a lot of custom cauls. I use custom cauls for a lot of things besides chairs; the caul is cut to nest the odd part and provide an opposing clamping surface. Oddly, I have a ton of pictures of stuff in the shop and not one of a shaped caul being used(?). I hope you get the idea from my text.

[Andy D Jones]

I would find those wooden hand screw clamps.

That's what I have used to re-glue stretchers that have slipped out of their sockets. Their wooden bodies are good for creating temporary blocks to clamp onto (or create stops to keep band clamps from slipping up the legs.)

Clamp one across the stretcher, near the socket, and another from the leg to the body of the other clamp.

-- Andy - Arlington TX

[Jim Becker]

You can glue blocks to your work to provide something for clamps to grab on to. Then you pare off the blocks with chisels, block plane, etc.
This...and in many cases, you can use the super glue and painters tape trick to avoid actually gluing the wood together. Another technique is to leave material on the components at the angle necessary for "square" clamping and remove it after the fact. Many ways to accomplish this task and they may be different for alternative designs.

[Jim Andrew]

Would not the long jaws of parallel clamps help with this? When I worked in a cabinet shop, one of the guys used duct tape to glue odd pieces. He wrapped the stuff on, and pulled tight at each corner. Really worked well.

[Paul F Mills]

Rubber hoses sound like fun...oh wait, wrong forum. They actually do sound like an option, I will check into them.

I have seen people glue Cutoffs to the work piece but I am hesitant to do that, too afraid I will ruin it when I remove the cutoff. I guess I need to do some practice pieces and find my wife’s hot glue gun.

Leaving excess material on the work piece sounds like an option too. I would have to put the template back on to route it off so I would need to be careful.

I have some of the Woodpecker Miter Clamping Tools that i did not even think about since they are intended for 45s, but they would probably work well for this.

Below is a picture of how I clamped it. It worked ok, I just figured there would be a better way.

[Edwin Santos]

Rubber hoses sound like fun...oh wait, wrong forum. They actually do sound like an option, I will check into them.

I have seen people glue Cutoffs to the work piece but I am hesitant to do that, too afraid I will ruin it when I remove the cutoff. I guess I need to do some practice pieces and find my wife’s hot glue gun.

Leaving excess material on the work piece sounds like an option too. I would have to put the template back on to route it off so I would need to be careful.

I have some of the Woodpecker Miter Clamping Tools that i did not even think about since they are intended for 45s, but they would probably work well for this.

Below is a picture of how I clamped it. It worked ok, I just figured there would be a better way.

Paul,

Seeing your project, I think your clamping approach could be improved, and you should consider something like the photos below:

431713431714


Since your angles will not be 45 degrees (i.e. a 90 degree workpiece joint), you can alter the angles of the clamping caul blocks accordingly, or you could use thin wedges to change the angles. The goal is for your clamping pressure to be across the joint. Use coarse sandpaper under the cauls to increase grip.

Another way is shown below with glued on blocks that are easy to knock off after clamping. Some people glue a piece of newspaper under the blocks to make removal easier, but I did not find it necessary to do that. This was for a dovetailed mitered case thus the clamping blocks needed to be narrow to go in the spaces between the dovetails.

431715431716

[Paul F Mills]

Paul,

Seeing your project, I think your clamping approach could be improved, and you should consider something like the photos below:

431713431714





I really like the looks of that. I could cut a number of them for different builds.
I may try the gluing blocks on that you and others have mentioned, but I think your other suggestion is what may work best for me at this point.

Thank you to all of you for the suggestions.

[andy bessette]

Another thing I sometimes do is screw blocks of scrap to my benchtop, just a little away from the assembly to be glued up, and drive wedges between the the blocks and the assembly to tighten the joints.

[bill epstein]

I'm surprised no one's mentioned band clamps. I've used the Jorgensen's for years to clamp large mitered corner boxes. From the pic I would think that would work

Just yesterday, I picked up a Bessey band clamp to try and it's got it all over the Jorgensen's.
A reel for the band and fine adjustment with an additional handle.

[Thomas McCurnin]

I started saving stout angled cutoffs a few years ago and spray painting them my typical jig yellow (so I don’t throw them out) and marking the angle. I use them for taper jigs and clamping.

[Doug Garson]

Have a look at this video around the 10 min mark, he does a glue up very similar to yours. https://www.youtube.com/watch?v=DIh_sXuv1QY

[Jamie Buxton]

I used the technique Edwin shows, but found that the clamp away from the joint would sometimes slide. So now I extend the arm until i can add a hook that wraps around the end of the workpiece.

[Jamie Buxton]

Here's a pic. I'm gluing up the long miter joint that forms a waterfall end on a countertop. Down at the floor, you can see the hooks that wrap around the end of the work.

431831

[Edwin Santos]

I used the technique Edwin shows, but found that the clamp away from the joint would sometimes slide. So now I extend the arm until i can add a hook that wraps around the end of the workpiece.

Jamie, did the sliding happen even if using coarse sandpaper glued to the underneath of the caul?

I like the extended arm and hook for a really demanding situation though. What your photo shows will not allow for any movement no matter how hard you clamp. Nice looking work!

[Jamie Buxton]

Jamie, did the sliding happen even if using coarse sandpaper glued to the underneath of the caul?

I like the extended arm and hook for a really demanding situation though. What your photo shows will not allow for any movement no matter how hard you clamp. Nice looking work!

I don't remember. I changed to the hook a long time ago.

To compare with and without the hook... Without, you get a block you can keep and use on many pieces of furniture -- well, as long as the miter angle is the same. With the hook approach, you need a new clamp device for each clamping situation. I usually just cut them crudely out of whatever scrap is hanging around, and put throw them back in the scrap bin when I'm done.

[Chris Fournier]

Dedicated cauls with geometry that directs the clamping pressure to bisect the joint angle is often my go to and if the glue up is a bear I glue the cauls with newsprint in the joint so the hold well enough but pop off and clean up easily.

There is no such thing as a ruined inner tube around me, I cut then into a continuous strip along the radius and these long rubber bands can be used to clamp any shape that you can create. And the price is right!

[mreza Salav]

There are different strengths of painters tape. The beige one is the strongest. If you use that on the surface of the wood and then glue another cut-off to that it would hold pretty strongly. The you can pair it off and remove the tape.

[Paul F Mills]

I'm surprised no one's mentioned band clamps. I've used the Jorgensen's for years to clamp large mitered corner boxes. From the pic I would think that would work

Just yesterday, I picked up a Bessey band clamp to try and it's got it all over the Jorgensen's.
A reel for the band and fine adjustment with an additional handle.

i bought a band clamp a few months ago and have yet to take it out of the package. I guess I should check it out.

[Paul F Mills]

Have a look at this video around the 10 min mark, he does a glue up very similar to yours. https://www.youtube.com/watch?v=DIh_sXuv1QY

that looks a lot like the photo Edwin posted. I will try it on the arms this weekend.

[Paul F Mills]

I used the technique Edwin shows, but found that the clamp away from the joint would sometimes slide. So now I extend the arm until i can add a hook that wraps around the end of the workpiece.

I will keep that in mind. Someone else mentioned roughing up the surface a little, so I will try that too.

[Mel Fulks]

I've used the blocks and they work well. I glue them with cardboard between the surfaces, then it's easy to knock them
off and scrape the remaining paper.

[Paul F Mills]

There are different strengths of painters tape. The beige one is the strongest. If you use that on the surface of the wood and then glue another cut-off to that it would hold pretty strongly. The you can pair it off and remove the tape.

I just used the standard blue tape I had on hand, I will look for the beige tape.

[Paul F Mills]

Dedicated cauls with geometry that directs the clamping pressure to bisect the joint angle is often my go to and if the glue up is a bear I glue the cauls with newsprint in the joint so the hold well enough but pop off and clean up easily.

There is no such thing as a ruined inner tube around me, I cut then into a continuous strip along the radius and these long rubber bands can be used to clamp any shape that you can create. And the price is right!

I have a too many road bike tubes lying around, I will try it. And it will be cheaper than the rubber tubing mentioned earlier.

[Chris Fournier]

I have a too many road bike tubes lying around, I will try it. And it will be cheaper than the rubber tubing mentioned earlier.
Once you have a bunch of your tubes cut up you'll find uses for them that you never imagined!

[Ira Matheny]

Chair makers use large rubber bands that are made for the assembly/gluing process. The rubber bands I use are about 36" in length. They can be wrapped around the standard chair several time. If you wish greater pressure, add more rubber bands