|Review by vipond33||posted 01-14-2013 03:02 AM||9936 views||6 times favorited||32 comments|
It is a very old saw that one cannot have too many regular clamps. At work for instance I run about 40 of the Jorgensen 3700 series and still wish I had more at times. Yet it is the specialty clamps that we have that sometimes get you out of a jamb or simply make life a whole lot easier.
To that end I have spring clamps, band clamps, little tiny C-clamps and a host of others that step up only when that seems the way to work. I’m sure you all have them too.
One of my specialty tools is the American made Dubuque models 76 & 76-A.
Made from cast aluminum and using a 1/2” true Acme screw, they are well designed and constructed with a good fit and finish to the parts. The screw is smooth and powerful, allowing precise adjustment of pressure. The casting ridges are nicely softened. There is a tiny rubber insert dowel put into the clamp pad holes so the thing won’t swing around by itself when you’re trying to offer it up with one hand. Nice.
These deceptively simple clamps work on the principal of a folding parallelogram (or of an inclined plane); the more pressure on the screw, the tighter the clamp faces grip – but parallel, even to the work-piece, not perpendicular.
This unusual design has a couple of advantages. For one, the clamp can be engaged very close to the joint. This means that very long pieces of wood need not require a long heavy clamp (and sometimes two people, and often damage). It also means that the squareness of the joint is easier to control.
This is a perfect clamp for pocket screw applications, difficult chair assembly (where it is impossible to clamp on a curve with normal tools), and furniture repair (where you do not want to disassemble or rip off and re-glue completely).
and as always, where you need to work on only one joint at a time.
As supplied they will handle stock from 5/8” to 7/8” thick and with the optional low cost “knuckles” up to 1 1/2”. Thinner stock than 5/8” can be clamped with a shop made wedge placed under one jaw face.
One problem that I did encounter with them concerns those jaw faces. These are rough machined (deliberately textured) to stop from slipping.
It is claimed that they do not mar the wood but I found that on very soft woods such as pine, this was not so.
However, this is easily remedied. I filed the faces smooth on mine and epoxied jeans weight 120 grit sandpaper to them. No marring, long lasting, perfect grip.
As far as I can tell from searching they are only available online from Lee Valley (Garrett Wade’s version is Chinese) but you may find other sources. They are also not to be confused with the Shop Fox knockoffs available from Highland, which have had poor reviews. There is also a mitre clamp attachment available for the Dubuque which, after inspection, seems to be of dubious utility & value.
Not for everyone, not for everyday, but a welcome addition to a complete problem solving kit, lumberjock or your daily routine.
and hello to anyone from Iowa, thanks.
-- firstname.lastname@example.org : dovetail free since '53, critiques always welcome.