bicycletricycle said:
bloomgrams is ameasure of elasticity in the glue, but how does that relate to camera re glueing?
Its more a measure of gel strength. For glueing leather to metal camera bodies one wants a cement that is strong but not too strong (since one wants to remove it without destroying the leather having it break at the bond), that's thin (don't want clumps under thin leather), does not maintain too much its stickyness once the bond gets broken (to not have it move about and collect gunk like fly paper), to dry slowly, be water soluble (we don't why volatile solvents), not gas out (why superglues are the last cement one would ever want to bring near a camera).... and, I guess, that does not encourage the growth of moulds or fungus and feeding of parasites.
Glues are a big chapter. Casein glues too are very popular (the white glue found in Elmar's brand tubs) and very strong and low in stress (related to how it dries). Buch binders tend to like to use glue made from bovine (cow) collagen.
Recall that camera leather is often meant to be peeled back or removed as part of servicing and maintenance. Sometimes even adjustment screws, for example to recalibrate focus, are hidden behind the leather.
Loads of glues are not meant to have their bonds be as easily broken. The auto industry, for example, use some very strong contact adhesives. Yes.. they hold.. but its like using Loctite on your jam nuts.. not always what one wants..