Bar clamps are some of the simplest wood clamps to use. For clamping large panels and furniture pieces such as table tops and door frames, there is simply no substitute. Their strength and durability make them a long-lasting and versatile addition to any workshop. There are projects where the length and strength of a pipe clamp are called for, but the weight of heavy galvanised pipe is too great. A wooden dowel can be substituted, using prefabricated pipe clamp ends, to create a wooden bar clamp.
Select 1-inch pipe clamp ends. You will need one screw clamp end, with a set screw and threaded clamp handle, and one sliding pipe clamp saddle for each clamp. They are typically sold in sets in various sizes and prices; choose the size that best suits your needs. Select a straight hardwood, 1-inch dowel free from cracks and splits. Lay the dowel flat on a level floor and turn it to determine if it is bowed. Discard any dowel with more than a ½-inch bow over 4 feet. Choose the hardest wood available -- oak and walnut are good choices.
Sand the dowel with two passes, start with 100 grit to level out any imperfections and shape the dowel. Run this over the dowel by hand. Make the second pass with 150 grit sandpaper to smooth any rough edges and make sure the entire surface is smooth enough for the clamp saddle to easily slide into position when adjustment is needed. Hand rub three coats of boiled linseed oil onto the dowel with a soft rag. Allow the oil to dry to the touch between coats.
Fit the screw handle end of the clamp set onto one end of the dowel with the flat plate toward the centre of the dowel. Slide the piece on until the dowel protrudes out the back ¼ inch. Tighten the set screw into the wood with a wrench. Tighten it until it is snug -- do not over-tighten.
Slide the saddle onto the opposite end of the dowel. Fit the clamp onto a work piece and press the square metal key plate in the sliding saddle toward the centre of the dowel to release it. Slide the saddle until the face of the clamp surface is against the opposite edge of the piece to be clamped from the face of the screw handle end. Tighten the screw handle to snug the clamp down.
Sand and oil the dowel as needed to maintain the smoothness of the surface. Tighten the set screw periodically to maintain its position; allowing it to slip can gouge the dowel.