There's an old axiom in woodworking that still holds as true today as it did years ago: a woodworker can never have enough clamps. Whether you're steam bending some wood to a form or assembling a glue-up of jointed hardwood boards for a table top furniture project or a set of cabinet doors, a variety of different clamps can be the difference between an average project and an exceptional one.
For many years, I built a plethora of projects using pipe clamps using 3/4-inch black plumbing pipe (threaded on both ends) and pipe clamp kits.
The advantage of these kits is that you can create pretty much any length of a clamp that you need, but the drawbacks are substantial. First of all, the pipe typically isn't strong enough to keep from bending under the strain of the clamps, particularly when you need to clamp runs of three feet or longer. If the pipe bends, that can cause the glue-up to have a slight bend as well, which does not make for a good table top.
Additionally, pipe clamps have a tendency to be cumbersome to work with, and if you want to stand the glue-up vertically to let it dry, you need to either lean the assembly against a wall, or have a series of pipe clamps on both sides of the glue-up to give you some stability for standing the glue-up on edge. That means you'll need a lot of pipe clamps.
Would you like to consider a better option? After my experience with pipe clamps and other styles of professional clamps, I was eager to test the Irwin 48-inch Parallel Jaw Box Clamp (model #2026501). These square box-style clamps are built with a solid, I-beam bar that would take a lot of pressure to introduce even the slightest bend along the length of the clamp. Let know more in this Irwin Parallel Clamp Review.
Irwin Parallel Clamp Review and Guide
The 90-degree jaws can actually clamp with up to 1150 pounds of clamping force, and under the heaviest loads I could put on the clamps, I couldn't detect any bowing or deflection in the rails.
Another benefit is that the two jaws of the clamp will actually engage 3-3/4 inches of wood, which allows for a more stable clamping action, particularly on thick pieces of stock that are being glued together. The design of the jaw distributes pressure evenly along the entire 3-3/4 length of the jaw for even clamping, and the resin body of the jaws resist allow glue to flake off easily and prevent damaging the wood stock as it's being clamped together.
As I was putting together a cabinet door glue-up (as shown in the image on this page), I noticed that, like some other bar clamps that I've used in the past, the I-beam bars do not have a series of notches on one edge of the bar for secure grabbing. In this case, the Irwin bar clamps are able to catch and hold at any point along the length of the bar without the need for any grooves to catch and hold the jaws in place. This is a huge advantage, as in my experience with clamps that use grooved bars, sliding the jaws into position to begin clamping can be a bit of a tedious process. Not so here. The jaws slid very easily up and down the length of the bar, right up to the point where I needed them to be. A few twists of the ergonomic grip twist handle and the cabinet door was locked into place to dry.
Now, one caveat to keep in mind. The Irwin 48-inch Parallel Jaw Box Clamp will end up costing about double what a pipe clamp with the kit and a 4-foot piece of 3/4-inch pipe will cost, so you're making a bit more of a long-term investment. However, the results will certainly be worth it, and I'm certain that a set of well-built parallel jaw box clamps like these will find hundreds of uses in your woodshop over the years, certainly more than justifying the additional investment.
Compared to other 4-foot clamps that I've used in the past, these Irwin 48-inch Parallel Jaw Box Clamps have vaulted to the head of the pack in my opinion.