What do you mean "a crack" is it a gap between two pieces of SS or a physical crack, where it's hit something?
If it's a physical crack then pop it down the welders to get it TIGged up. Will only cost you a couple of quid (probably cheaper than a tin of epoxy) and shouldn't take but a few moments.
If it's a join then any type of marine sealer/epoxy will do, you can get most colours these days or even use clear stuff.
Looks Slow but is Fast
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