Originally Posted by riderx
The problem with this is, there may be structural damage that can't be seen that will eventually fail too. And if something has already begun to crack, especially if it's old, chances are it past it's useful life.
I'm a cheap bastard, but sometimes you have to know when to retire a part to the junk bin. Dental work is generally more expensive than a new set of cranks.
Sure..in some cases with a crack it's best to retire the part..in this instance though I'm thoroughly familiar with the crack and crank in question. The area where the crack started at the spider is thinner and sharper than the rest of the crankarm/spider. Therefore, the removal of a small amount of material enough to eliminate the crack, leaving a rounded profile will solve the problem. If this thinner material had been removed at the factory, the crack would have never started.