Today I used some 600 grit "Clover" silicon carbide impregnated grease (valve grinding) compound to on the fixed and adjustable cups of a Shimano BB-7410 bottom bracket that I'm getting ready to use. I bought the bottom bracket used off ebay - its the 103mm square drive one that goes with Dura Ace FC-7410 8-speed cranks.
The aluminum bottom bracket cups were corroded onto the steel body of the sealed bottom bracket. It took me quite a while just to get the seized cups separated from the body. But once I did, the corrosion and residue of some thread locking compound was so nasty that I had to resort to abrasives to smooth out the mating surfaces. I actually used some fine emery cloth then moved onto the 600 grit Clover compound. The cups were like an interference fit even after the corrosion was gone and even as the surface became more polished. I kept rotating the mating parts back and forth against each other with a generous amount of the Clover compound until I was satisfied that I could assemble and disassemble the parts by hand with minimal persuasion every time. I may have even gone a little overboard and induced the slightest amount of slop into the equation.
Anyway, I just thought I would share a shop application for valve grinding compound in bike mechanic work.
Does anyone know of other bike mechanic applications for this product?
One other question, was it Shimano's customary practice with their sealed bottom brackets to use adhesives or permanent loctite on the aluminum fixed or adjustable cups? If not, I'd say the former owner of this bottom bracket nearly butchered what should be a very serviceable sealed bottom bracket.
