I bought the $.99 spring clamps from Home Depot. Besides the price I liked that there was a hole about and 1.5" from the tips. I thought I could figure out a way to hold a piece of rubber (bike inner tube) to add an inward force to the strips. All my ideas seemed like too much work so I used the 6" rubber strips stretched and clamped as I saw on this site, sorry I don't remember who. It works well but I still wanted a permanent attachment of the rubber strips so clamping would a be one handed operation.

To see if it would really work I stuck the ends of the rubber through the holes, and was surprised that there was enough friction to hold the rubber strip in place while I stretched it over the wood strips.

I will use 8" long rubber strips next time. That should make them more forgiving when the rubber is not centered.

Since the strips are not permanently attached to the clamps they can be removed in seconds. They are quick to replace if needed.

The springs in the HD clamps are very uneven in strength and I picked all the strongest ones. Some are too strong and will dent soft cedar.

One problem I am running into is the handles get in the way near the ends. I am thinking of trying the PCV pipe clamps, and drill a hole in each half for the rubber strips to do the same thing in a 3" or 4" clamp.