Big Jaw Pipe Clamps
Pipe clamps are a cheap and easy way to clamp glue-ups, but they only apply pressure on the first few inches near the edge. You can always alternate clamps on the top and bottom to apply more even pressure, but this only works for stock under 5″ thick or so. If you’re putting together an even thicker slab, you should probably make sure you apply pressure to the middle, too.
One way to reach the middle is to use some of WoodCraft’s Big Jaw Pipe Clamps that have a 7″ throat depth. Made from ductile cast iron, the clamps fit onto standard 3/4″ threaded pipe. To make the clamps easy to adjust and release, they have multiple disc clutch plates.
A single Big Jaw Pipe Clamp will cost you $22; if you buy four or more the price drops to $20.
Big Jaw Pipe Clamps [WoodCraft]
Via Amazon [What’s This?]
You could mill the face of the clamps to change the force.
Not sur if they are still available – but a company called Wade Manufacturing out of Portland Oregon – made a set of whath they called Mastodon Jaw Extenders – that slipped on regular pipe clamps:
http://www.macmurraypacific.com/catalog/sec19.pdf
These are great clamps. They are still made and still very reasonably priced. I found that Amazon sells them in singles, 4 packs and 8 packs. The prices are the same as Woodcraft, but the shipping is better at Amazon.
Please update both the Woodcraft and the Amazon links, as I could not find this product on either site.
Amazon does have the Wilton equivalent, for three times the price!