On Monday, February 13, 2017 at 4:26:57 PM UTC-8, Leon wrote:

[on clamp maintenance]

Unnoticed being the key word. Or possibly the clamps are not being used
enough to need any TLC, YET. ;~)

One of my favorite glue clamps is a piece of 2x6. A one foot section
of steel, 2" by 6" cross section, weighs about 40 lbs. It's very low maintenance,
and in conjunction with some polyethylene foam, clamps even irregular surfaces effectively.