How to Use Bar Clamps

There are several types of bar clamps used in a wide variety of scenarios. A selection of bar clamps is a necessary component of the woodworker’s tool kit. If you are seeking to understand the many types of bar clamps as well as the situation and application for which each clamp is best suited, continue reading.

How to Use a Pipe Bar Clamp

Pipe bar clamps are essential for large woodworking projects, especially when gluing pieces of wood together under pressure. While the adjustable clamps on many pipe bar clamps are finicky, the concept of a pipe bar clamp is simple enough.

How a Pipe Bar Clamp Works

A pipe bar clamp begins with a long pipe that is usually iron. On one extremity of the pipe is a fixed end with stabilizing legs. Along the length of the bar is an adjustable slide.

The adjustable slides vary in kind.

• Some slides work by locking into pin holes drilled along the length of the pipe.
• Other slides have a pinch clamp. To work this type of slide you will need to pinch and hold the clamp, then slide the clamp along the bar.

Pinch slide clamps can be difficult to use. If the clamp is not pinched completely or if you try to move the clamp any way except perfectly parallel to the bar, it will bind up. Practice and patience will eventually make using pinch slide clamps convenient to use.

Fixed End Clamp Types

The fixed end clamp on your pipe bar clamp usually comes in one of two different styles. The simplest version is a stopper. With this type of end, wood is pushed into the stopper and held in place by pressure applied by your sliding clamp.

The fixed end for your pipe bar clamp that I recommend has an adjustable stopper. This adjustable stopper on your fixed end bar clamp can be worked to apply pressure to anything placed between itself and the adjustable clamp.

Often the adjustable fixed end bar clamp has a long handle that is turned as if spinning a wrench. Powerful mechanical force is applied to your clamped project. Pipe bar clamps can help you cleanly glue thick wood as well as warped or bowed wood.

How to Use a Pipe Bar Clamp

We advise using pipe bar clamps when you are working with large projects. In theory, a pipe bar clamp is only limited by the length of pipe to which you have access. A common use for pipe bar clamps is when creating custom cabinet doors.

After your wood has been shaped, planed, and joined by biscuits, all seams can be closed using pipe bar clamps. An example of how to use pipe bar clamps to join long boards together is below.

Tools and Materials: 

• Wood Glue
• Level Surface
• Sandpaper
• Spirit level
• Paper to catch glue drippings
• Pipe clamps (try to have a pipe clamp at least over 12” running perpendicular to your seams)

Method:

1. On a level surface, lay down your paper to catch any drips squeezed from between your boards. The compression from pipe bar clamps can discharge a surprising amount of glue.
2. Place your pipe bar clamps on top of your paper. The pipe bar clamps should have all fixed ends aligned with 12 inches of space between each pipe bar clamp. The lengths of the pipe bar clamp should all run parallel to one another.
3. Place your spirit level across your pipe bar clamps. Add shims as necessary beneath the stabilizing legs of your pipe bar clamp.
4. For extra-strength adhesion between boards, use sandpaper to rough up edges where the boards will join. Wipe away all excess dust.
5. Lay down your straightest board along with the fixed end stoppers of your clamps.
6. Glue the edge facing away from your fixed end stopper.
7. Add your next board, then apply glue to the end facing away from the fixed end stopper.
8. Continue this process until you reach your last board.
9. With your last board do not glue the outside edge facing away from the fixed end stopper.
10. Use your adjustable slide clamps to firmly press the board together.
11. Tighten your adjustable fixed end stopper until all gaps between the boards have been closed. It is helpful to begin tightening in the middle of your project, then work outwards tightening your adjustable fixed end clamps until clamps are tightened and all gaps are closed.
12. Wait until the wood glue has dried per manufacturer’s instructions, then release pressure by slightly relieving pressure on one clamp, then the next, and continuing to work up and down your line of clamps gently releasing tension until clamps are free of pressure.

Tip: When tightening, some boards will not sit flush on top of a pipe bar clamp. When this happens, you may place wax paper on top of the area, followed by a heavy weight to press the board flush. A way to make this problem less likely to occur is by joining boards using a biscuit cutter before gluing.

How to Use a Sash Bar Clamp

While pipe bar clamps are the most common type of bar clamps, there are a handful of other useful clamps that belong to the bar clamp family.

Sash clamps are very similar to pipe bar clamps, but rather than using a strong pipe, sash clamps are usually made from hollow-bodied, square aluminum tubing. These clamps also have a fixed end stopper with many of the fixed ends being adjustable.

Sash clamps come in a wide variety of sizes and can be used in nearly every application that a pipe bar clamp can be used. However, given the square body of the bar, for best results when using sash clamps you must have an absolutely level surfa. 

Slight undulations in your surface produce more dramatic effects on your work given the wider resting surface. With pipe bar clamps, projects only rest on the crest of the pipe rather than across the wider, flat body of the sash clamp.

How to Use a Quick Release Bar Clamp

Quick release bar clamps are great in pinch and can often be used one handed. This type of clamp does not require resting on a broad level surface like a pipe bar clamp or sash clamp.

Quick release bar clamps are highly mobile and generally smaller. I recommend them on my list of top woodworking tools.

The size, ease of use, and limited pressure capacity of quick release bar clamps make them ideal for temporary projects when something may only need to be clamped for a few minutes or hours.

To use a quick release bar clamp:

• Place the non-adjustable fixed end on an outside edge of your project to be clamped.
• On the adjustable end is a small trigger that can be squeezed, which allows the adjustable slide clamp to move freely along the bar.
• Center the slide clamp against the wood directly opposite the fixed end stopper, then squeeze the handle of the slide clamp.
• With each squeeze, the clamp will tighten.

Be warned, though. Quick release bar clamps cannot safely apply as much pressure as pipe bar clamps and sash clamps. Too much pressure on the quick release bar clamp will break.

Conclusion

When looking for a bar clamp, pipe bar clamps are the most common and are incredibly versatile. Quick release bar clamps have an important place in your toolkit and do belong to the bar clamp family, even though the quick release bar clamp is rarely referred to as a bar clamp. Use sash clamps much as you would a pipe bar clamp on your true, level surfaces.