A most useful tool
© Frank Ford, 4/24/98; Photos by FF, 1997
Over the years I've made my share of kinetic sculptures You know, the kind where you're just tightening the last of about 40 clamps placed across, up, down and all around an instrument and one of them slips. Then more of them slip. Then you yell. Then you start over.
Some instruments, whose makers will remain anonymous, but whose initials are "G-I-B-S-O-N" have a chronic problem where the sides come loose from the lining and start to bulge out. (Sometimes its the back coming loose from the lining, but if you're really lucky, then both are loose!) It takes a hell of a lot of pressure to squish them back.
Here's a method I worked out to get ultimate squeezing power all around an instrument body.
Years ago, my tool guru and neighbor, Brian Burns, successfully talked me into trying a softwood bench top made of laminated fir 2x4s. He said my maple bench was a bit precious and I'd be hesitant to beat it up. He was right. I really like my softwood bench top. It's sturdy, massive and I can abuse it without feeling guilty.
I bought a whole bunch of 1/2" thick aluminum plate. (I don't
know the alloy; I'm sure any would be fine.) I made a template and traced out a couple
dozen patterns for these heavy L-brackets. I tapped holes near the top of one leg,
drilled and countersunk a hole diagonally right in the corner.
Now, I use my ball-joint vise to suspend the instrument with the body parallel to the bench top so that the point I want the pressure lines up with the height of my upper L-bracket holes. Sometimes, I'll just place the instrument on blocks rather than suspend it from my vise.
Then I take out my trusty Makita and a flock of standard power drive deck screws and go to work:
Before attacking the needy area of the side, I'll place some of the clamps around the perimeter to hold the instrument rigid. It only takes the one deck screw, and the L-bracket can pivot a bit if necessary to align it. I pad the upper 14-20 threaded bolt where it contacts the sides, using leather faced plywood with a recess for the bolt.
It's a snap to drill and place one of these clamps exactly where I need it.
This is a Gibson L-5, circa 1930, all trussed up:
Before long, I have my instrument supported and I can do a quick dry run, using a flexible backing board where I'm mashing the side back in position.
Here's a bird's eye view:
The power of these little clamps is amazing.
Back to the Gibson A-1 mandolin from the first view:
This one had the back loose from the lining and the side was bulging, so I had to clamp from the top and back as well as from the side. If you look closely on the right you can see my hide glue beaker. With this system and the little one-handed clamps, I can work fast enough to use traditional hot hide glue.
Here's a 1923 Gibson F-5 getting the same operation. This time I have the clamps spaced to allow me to push the bulging side in and reglue the loose lining and endblock all across the end of the instrument:
I'm using miniature Quick Grip clamps between my bench clamp uprights.
OK, job done. Next day all I do is unscrew the brackets, put them away and repair the bench top:
I keep a bunch of the right size dowels cut short and ready to use. I just dose them with Titebond and tap them in place.
Without waiting for the glue to dry, I simply slice them off with my utility razor saw:
I have two of these saws. They take a relatively inexpensive replaceable blade. I simply mark the duller one so I'll reach for it for these little rough jobs.
My bench is back to full integrity and ready for the next job. . .
Update, 4/17/01: The results of a four month test on the effectiveness of side compression.
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