by mark48 on Mon Jun 01, 2020 4:37 pm
Hi Tom and all PS builders,
With a bit of internetting, I now realize that the problem preventing me from un-threading my stainless steel cleat bolt was a process called "galling." Apparently, if one twists a bolt of stainless steel too swiftly in threading or removing the nut, the generated heat within the mating thread surfaces melts some microscopic metallic bits left over from manufacture effectively welding the bolt and nut together. There are plenty of links describing this process; it can happen while either threading the nut onto the bolt or removing it, and if it happens, there may be no recourse other than to cut the bolt in two.
Galling can be prevented by threading slowly, avoiding use of power tools while manipulating bolt and nut (I was working only by hand in my situation), and using a thread lubricant - especially if one is threading lock-nuts which generate yet more heat.
Although I considered heating the bolt with a soldering iron, I was reluctant to apply significant heat to the bolt in my PS installation, concerned that I might cause unrecognized damage within the plywood or even start a fire. Ultimately I hack-sawed through the offending bolt and cleat leg, and then backed out the residual bolt pieces without difficulty.
Moral of the story: avoid galling.
All the best,
Mark