How to Use Bar Clamps

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  • 1-2 hours
  • Beginner
  • 0-100
What You'll Need
Safety glasses
Spray can of penetrating oil
Bar clamp
Wood or carpenters glue
Rubber gloves
Finishing nails (optional)

Bar clamps are handy for light duty woodworking projects that require clamping and firmly bonding two pieces of wood together. A bar clamp consists of an aluminum or steel bar and two jars, one is static (also called fixed head) and the other is a tail stop that can be adjusted with a screw mechanism and tightens when you turn the crank. They measure from 6 in. to 36 in length and can reach 2 in. to 2-1/2 in. Some are designed to join to pieces together, and others can be used to push pieces apart with outward pressure. Keep reading to learn how to use a bar clamp.

Step 1 – Select the Right Bar Clamp

Bar clamps are available in many sizes. Select one that is best suited for your project. The two pieces of wood you will be joining should both fit between the two jars of the bar clamp, also known as the jaw opening.

Step 2 – Prepare the Bar Clamp

Make sure your bar clamp is clean and that all parts work. This will prevent wood from spitting or falling apart, inaccurate positioning of the wood, and possibly even self-injury. Wear your eye-protecting safety glasses from the start of this step on.

Open the jaws to their full capacity. Apply penetrating oil to the clamp. Follow the directions specified on the spray can. Spray a thin coat to the steel or aluminum bar, at a distance of about 4 inches away. Then spray the other parts of the bar clamp. Keep your mouth closed to avoid inhaling spray fumes.

Use a cloth to wipe away any excess oil. You want to make you remove it all so that it won’t penetrate the wood you will be working with.

Set the bar clamp on a workbench or working surface.

Step 3 – Clamp the Wood Pieces

Join the two wood pieces on your working surface. Don’t worry if the alignment is not perfect at first; you can loosen and readjust the clamps as needed. Adjust the bar clamp to fit the length of the joined wood, extending the jar opening an extra 3 inches. Place the fixed head and the tail stop against the edge of the two wood ends. Turn the handle (tail stop end) with the screw mechanism to clamp the two pieces together.

If you are working with soft wood, you may want to insert a piece of scrap wood between the jaws and the two wood pieces. This creates a buffer to prevent impairment to the wood being clamped together.

Use your fingers (you may want to use rubber gloves) to apply and glue to each part of the joint. Spread it around the edges.

Use moderate pressure. Don’t over-tighten. This could cause damage to the wood and even bending of the pipe. When you see glue being squeezed out, you’ve applied enough pressure.

Wipe off excess glue and let dry.