I don't know if this is really new, but here goes: I have had a plumber under my house for a few days now, doing copper repiping. When he finished the other night, we tested the system by opening the main valve, listening for leaks. There was a big one under a bathroom, so big he thought he must have missed soldering one joint. Crawling back to the problem area (now a large mud puddle), he tried to re-solder the joint, and with all the water in the system, it was just too hard. He went home for the night and we shut off the main. Next day he discovered that virtually every joint he soldered the day before was bad. He could just pull them apart. He threw away his solder and flux and started over with new stuff, all the while thinking about what could have gone wrong. First we suspected the flux had become contaminated with something under the house, but the more he thought about it, he remembered that he had used some cheap acid brushes from Harbor Freight to apply the flux and he likes to continue to brush on flux while soldering, to clean up drips and make the joint neater. The brushes had a melted appearance, unlike the ones he normally uses, which I assume are some kind of natural material, probably horsehair. Our best guess at this point is that the brush he was using was melting as he applied more flux to the hot joint, and the brush material contaminated the solder-to-pipe bond somehow. Sound reasonable? Gary Hastings
- posted
16 years ago