Q:

I recently did a glue-up that required more clamping pressure than usual. I used Jorgensen clamps with soft-plastic pads. When I removed the clamps, the pads had left stains on the wood. What’s causing the stains, and how can I deal with them?

Richard Nellen, Brookfield, WI

A:

You’re encountering oil stains. Adjustable Clamp Co., which makes Jorgensen clamps, uses a softer plastic for its accessory pads than many other companies. Under heavy clamping pressure, the plastic can exude a bit of oil, which taints the wood.

If extreme pressure is required for the job at hand, you can head off the staining problem by replacing the plastic pads with sacrificial wood pads. I use yellow glue to attach pads made from 1/4-in. plywood scraps to my Jorgensen clamps.

The glue holds the pads in place but releases them under a firm tap from a hammer when the pads need replacing.

If you need to remove clamp-pad stains from existing workpieces, lightly sand the affected areas or wipe them with mineral spirits or naphtha. Either one should do the trick.

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