Pratley Putty has also been used to repair cracking in a main support of the Golden Gate Bridge in San Francisco. As it sets underwater, it's even been used to repair sunken ships before refloating them. This a South African product which is hard to beat!
I use it a lot myself around the home, mostly for my aquaponics projects. It's great for stopping leaks, and before it sets (it only takes about 20 minutes to harden and then sets stronger than steel) it can be easily worked into shape and smoothed with a wet finger. It dries to an offwhite colour.
As with liquid epoxy resins, it only becomes sticky when two components are mixed; ensuring a long shelf-life and no problems with setting during storage. It adheres to metal, stone, cement, concrete, slate, glass, wood and just about any other rigid material.
Pratley also make a Quickset and Steel version of their famous putty. They do other great adhesives as well, you can check out
their website for the full range. You can read more on the history of the company
here, it's fairly interesting.
I doubt you'll be able to find this stuff in your local hardware store, but I guarantee I'll sell it cheaper. I'm thinking about 4 - 5 USD
per pack, shipping won't be much as it's light (125g).
