DIY Long Reach C Clamps

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sploo

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Earlier this year I "upcycled" our old pine bed into a shoe rack (a-shoe-rack-from-an-old-pine-bed-t92769.html). I had a tiny bit of wood left, and sometimes need long reach clamps.

Working from Matthias Wandel's design (http://woodgears.ca/clamps/) I set about resawing the short bed posts (split dowels, holes and all), and ripping what parts of the headboard I had left:

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I don't have a box joint jig, and in any event the depths I'd need to cut would be way beyond the reach of my table saw or any router bit I have. As such, I went for a simple bridle joint, mostly cut on the bandsaw and finished with a chisel:

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And... I screwed up.

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Fortunately I still had the offcuts from the mortices that I'd hogged out with the bandsaw, so I glued thin sheets onto the tenons and cleaned them up with planes and chisels. IRC it was this job that finally convinced me to buy a vice (and a Veritas Router Plane). Fortunately the end results were OK:

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Handles:

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Chiselling the recesses for the nuts:

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A dry fit:

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After the dry fit I decided to plane off all the remaining varnish (aesthetics won over just getting the job done :wink:). I rounded over some parts on the router table and glued them together. I also used dowel to plug some of the holes and then rounded the rear corners using the bandsaw and disc sander:

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Next, the pads were made from some scrap hardwood, and the threaded rods modified (drill press as a lathe + angle grinder):

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Because I didn't think my joints were that great, I decided to pin them using a couple of dowels. Once trimmed with a chisel, a pass with a #4 plane gives a nice finish, and the spine edges were rounded over:

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I wanted to colour the parts but liked the grain so I didn't want to obscure them with paint. Being too cheap to buy real wood dye I experimented with blue and red food colouring. IRC I used a 2:1 mix of water to colouring. 38ml bottles were more than enough. Note how the colour hasn't taken on the resinous knots. I actually quite like the effect, but perhaps if I'd used white spirit (US - mineral spirits?) it may have worked better:

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At this point I had a problem. Brushing on the water based floor varnish I like to use would make the colour run, and whatever ingredients there are in the food colouring doesn't really dry completely, so with hindsight it wasn't a great choice. I bought some spray cans of varnish, and eventually had a dry/mild/calm day to do the job (in England in December... who'd have thought).


Putting the handles and rods together. I'd drilled a shallow pocket on the top of the handles, and tapped a hole for a 4mm bolt. I put a small amount of superglue at the head end of the bolt threads to ensure they stayed in the thread. More on why later:

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Pads pinned on with small nails:

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The finished clamps. In this photo the blue doesn't really show up at all. It's definitely subtle, but it's much more obvious than on these shots. You can see that it's taken to the end grain much better:

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So, why did I put the 4mm bolts on the handles, like this:

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The answer is that the pocket diameter and bolt protrusion is just enough to fit the jaws of a drill driver, and it makes the tedious job of opening or closing the clamp really fast (a matter of seconds for a full sweep, even with these fine threaded rods):

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Some extra notes following a brief discussion with Matthias:

The rod I used is 12mm (M12). The gap between the jaws is approx 21cm and the total jaw depth is just over 35cm (so I can get to the middle of my ~70cm deep bench). The stock for the horizontal sections is approx 3cm wide by 5cm tall. The vertical section is 4cm wide and 9cm deep.

In the interests of "science" I thought I'd do some tests on opening and closing times. Fortunately the alignment of the nuts was good, and with a tiny bit of 3-in-1 oil on the threads they spin very freely.

By spinning the handle manually I was able to do a full travel in 35 seconds. Spinning the rod between the palms of my hands took just 18s.

I then tried spinning the whole clamp by holding the handle (somewhat like an old football rattle). Very slow and cumbersome, and downright dangerous in my tiny workshop.

Finally, I found that I could pop a hex bit out of the drill driver, lock the jaws onto the 4mm bolt and close the clamp in just 8 seconds. However, opening the clamp takes a few more seconds as you need to reverse the direction of the drill after closing the jaws.

So, it's faster, but probably not sufficiently faster to make it worthwhile (unless you literally had the drill in your hand). If the rod was a bit more stiff to rotate by hand the difference might be greater.
 
Can I suggest a small upgrade
Epoxy or studlock a nut onto the thread in the end of the handle - you can then use a nutdriver in your drills bitholder
Matt
 
Shrubby":63x4bpv9 said:
Can I suggest a small upgrade
Epoxy or studlock a nut onto the thread in the end of the handle - you can then use a nutdriver in your drills bitholder
Matt
That's a good idea, and it would make the clamp a better "product"; though of course it then means you've got to find and insert the right bit (which adds time :wink:).
 
A small update...

Using the food colouring really wasn't a great choice. I assume there must be some fat or protein in the dye (in the red, anyway) as I noticed some mold growth on the handles (my garage is terrible for condensation and damp).

It was easy to sand off, and because the spray varnish seemed to have sealed the dye reasonably well I gave them a few brushed coats of the water based floor varnish. They certainly look and feel much better now (the red colour is better too). Hopefully that'll seal them properly.

I have no wall space on which to hang them, but I'd planned on some cleats/hooks on the "dead" space either side of my main bench-cum-router table. Simple bits of pine, with the rebate width slightly more than the width of the horizontal sections, but slightly less than the width of the vertical rib. As such, they drop in and sliding them forward gently provides some grip so they don't rattle around.

One side shown below, the other side is identical:

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Nice work and a good clear post with great pix, thanks sploo.

"The job's a good'un".

=D>

AES

(Yet another "roundtoit"!)
 
Look real nice. Also when I want that kind of translucent color, I painted the stuff with the dirty mineral spirits I used to clean my brush with last time, the result from the green color I often use was a lot like yours. Then I put varnish over it.
 
DennisCA":1cyvfufg said:
Look real nice. Also when I want that kind of translucent color, I painted the stuff with the dirty mineral spirits I used to clean my brush with last time, the result from the green color I often use was a lot like yours. Then I put varnish over it.
That's a good idea (and cheap)!

Having now experimented with Fiebings leather dye, I'd definitely use that next time. I believe you can cut it with methylated spirits (denatured alcohol). It's relatively cheap, and even reduced in shellac (for a dyed shellac coat) the colour is strong.
 
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