I have been asked to repair a couple of brass cymbals from a drum set. They have cracks that run parallel to the diameter. Can they be brazed with o/a? Is there any secrets to share? Heat treated, warping or whatever? Thanks Scott
You can do, of course, whatever you want, but it won't be much of a cymbal when you are finished. The usual options are to drill a hole at the end of the crack to spread out the stress, or cut down the cymbal to eliminate the crack. You will have a different cymbal at that point; it may sound good or bad. For short cracks starting at the center hole, I have made a brass washer and epoxyed it to the center hole.
Cymbals worthy of the name are bronze. The cheap ones are 8% tin, because they can be stamped from a sheet. The more expensive models are around 20% tin. This alloy is too brittle to roll in a sheet. The cymbal maker starts with a biscuit of cast alloy, heats it red hot, pounds and rolls it flat, stamps it to shape, scrapes grooves in it on the lathe, annealing as required. Then the cymbal is hammered to work harden it. The Ziljian and Sabian sites have pictures of the process.
Here's what I learned in music school. Drill a small hole at the inside end of the crack to keep it from "running". Then cut a small V shaped notch with the big end at the rim of the cymbal and the point ending in the hole you drilled. This keeps the "sides" of the crack from rubbing together and distorting the sound. Randy
i don't know anything about it, but, couldn't you, as they said, drill holes at the ends of the cracks, but also, drill holes along the crack ever inch or two and put in some copper rivets and peen them over? i mean, isn't how they "fixed" the liberty bell? i really don't know though.
Knowing very little about cymbals, I will offer the following suggestions, based on what I would try. 1.) I would not do anything if the cymbals sound okay now, or if the owner has an alternative that promises to work.
2.) If the only other choice is to throw them away, I would silver solder the cracks, and then peen the area to restore hardness. Soft metal doesn't ring.
You might try laser wlding. I found a local jewelry store that did a great job welding some silver for me. Weld it with brass and carefully hammer the finished weld to bring the cymball back up to tune, tap testing as you go. Bugs
The cymbal is basically trash as the others have sort of indicated. Cymbals are highly hardened brass and any heat work on them will soften them to where they sound different. Even soldering them with any silver solder will affect the hardening of the brass and lead/tin soldeer won't be strong enough to make a good joint.
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