Friday, May 5, 2017
There isn't a rule stating what the ideal clamping pad material is. But if there was one rule it would surely would be to make certain the clamping pad you plan to be using is softer than the wood you are clamping. For example I wouldn't recommend using hard maple pads to clamp eastern white pine. The reason being is the hard maple will most likely dent the pine under clamp pressure.
Most my clamping cauls I use are either plexiglass, thick leather, bending plywood, or homasote soundboard. Each has there place but all of them won't dent the wood. There are times in gluing or repairing furniture that I want make certain I can see my joints/repairs coming together nicely and this is where the plexiglass comes in nicely. The bending plywood is great for areas that not straight and I need the plywood to conform to the surface. The thick leather is often used for really delicate glues up. Lastly the homasote is used for all general purpose glue ups.
There are times where I do use wood for cauls for when clamping dovetail drawers or chests. Or even when I am making chairs and need angle wedges. But after that I use the pads mentioned above. I keep them all in a wooden box with handles ready and with in reach. Its amazing how many you need and the wide selection of sizes.