A rotary drum blancher/cooler includes skinsheet sections alternating with structural channels and clamps. The skinsheet sections and channels have sidewalls. Each clamp includes at least a portion of a clamp bar, a bolt, a slot and hole combination, and a nut. The clamp bar holds each skinsheet sidewall between the channel sidewall and the clamp bar. The bolt extends through a hole in the clamp bar. The bolt has a first partially threaded end and a second end with at least one groove. One end is within the channel, and the other outside. A slot and hole combination is located in at least one of a retaining plate, channel sidewall and clamp bar. The bolt can pass through the hole of the slot and hole combination, and the groove(s) in the bolt are disposed within the slot to prevent rotation of the bolt. The nut is on the first end, and may be tightened or loosened to tighten or loosen the skinsheet side wall to the channel sidewall.