Posted by Rick Denney on April 10, 2003 at 14:43:56:
In Reply to: Repair estimate posted by Dean on April 08, 2003 at 21:58:13:
It's not a matter of "sealing." If it doesn't carry air, there's nothing to seal. Because the part is there for structural reasons (to give you something to hold), the crack has structural consequences, not leakage consequences for which sealing might be a fix.
As I look at the picture from an engineering perspective, though, I see a fatigue failure. This was probably caused by some really high internal stress from production, or a flaw in the metal, or (most probably) both. Your statement that it isn't caused by trauma must be correct--I don't see how trauma could cause a crack like that. Brass just isn't brittle enough.
The problem is that if the stress still exists, the crack will continue to travel. The tip of a crack is a stress concentration that is dramatically higher than the base material. Unless you join the two ends of the material together with something stronger (and stiffer) than the base metal, the crack will continue to grow. So, how to you get a strong and stiff repair? There are two ways: One is to join the crack with a material as strong as the base metal, or thicker enough so that it doesn't have to be as strong. Silver soldering would do that, but silver solder is a high-temperature process that will melt the silver plating, as Joe says. The stuff that Chuck suggested isn't really silver solder--it has something in it to lower the melting point--but it might be strong enough.
A mere "sealant" would not accomplish anything.
Another option not yet mentioned is to put a patch over the crack. You could make a patch out of brass that is just right, have it silver-plated (any jewellry plating shop should be able to plate a piece this small), and then have it low-temperature soldered in place. That might be a much cheaper repair than the other techniques mentioned. It won't be invisible, but it might not also look wrong if it is well done. What it will do is solve the problem that is causing the crack.
Given that it is likely caused by a manufacturing fault, I would still go to Willson about it even if you think it's out of warranty. They might say no, but they might not. You have nothing to lose by asking. I would go straight to the factory, if you can find a way to do so--they may be more willing to take it on the chin to support the reputation of their product than a distributor.