Clamping pieces of wood together is central to working wood. Clamps are usually the answer. Having enough of the right type on hand and knowing how to use them will pay off.
1. Have many types of clamps on hand – “F,” “C,” spring, bar/pipe, parallel, band and trigger are all different types of clamps that operate differently. They all have their strengths and weaknesses, so having some of each is a smart approach. Be familiar with what each type of clamp can do.
2. Vary the lengths – Some woodworking tasks require a short, small clamp, while others require a very long clamp. Most clamps are available in short- and medium-length versions; bar/pipe and parallel clamps usually come in much longer versions. Unless you build only small projects, it’s good to have a variety.
3. Always apply force perpendicular to the joint – Usually this is the most obvious way to apply force, but when working with curves and angles this can be harder to do. Jigs and angled cauls are the answer.
4. Don’t under tighten – Not applying enough pressure will cause a weak bond. Generally speaking, softwoods need less pressure than hardwoods. Also keep in mind the strength of the clamp. It’s easier to apply a lot of force using “C,” pipe/bar and parallel clamps. On the other hand, a trigger clamp won’t be sufficient when edge gluing large planks.
5. Don’t over tighten – Applying too much force will cause a starved joint, may distort the project while it’s drying and may cause damage to the wood fibres it comes in direct contact with. There’s a correct clamp for every job, and a different amount of hand strength is needed to appropriately tighten each type of clamp.
6. Use enough clamps – Just because a pipe/bar clamp can produce a lot of force doesn’t mean two are enough for a 48″ edge joint. Space clamps evenly across a longer glue edge so the entire length has pressure applied to it. More clamps, each applying less pressure, is usually a better approach.
7. Use cauls – Essentially just a collection of different-sized solid wood and plywood offcuts, shop-made cauls can help spread clamping pressure across a larger area. They also help protect the workpieces from getting dented and damaged by the heads of the clamps.
8. Store your clamps properly – Storing clamps on wall-hung racks is the most common approach, though there are others. Ease of access is important when reaching for a clamp. And the fact that a properly hung clamp won’t get knocked over is a huge plus.
9. Use accessories – Clamp supports, bench dogs, 90° clamping squares and many other accessories make a tough clamping situation easier. My personal favourite? Iron couplings can be used to extend the length of my pipe clamps indefinitely.
10. Create sub-assemblies – Medium- and large-sized projects need to be broken into sub-assemblies to be successful. Glue dries quickly, things can go wrong and if you try to bite off too much at once you’ll find the glue too dry to properly work, a nightmare scenario that’s avoided with sub-assemblies.
Rob is a studio furniture maker and the editor at Canadian Woodworking & Home Improvement.
