Ok…I have seen several answers to this but I want to ask something related…
I just worked for 16 hours, teaching my son to sweat copper. We re-did his whole house, pulling galv and replacing with copper. It is a small ranch, so 95% of the pipe is in the furnace room and the rooms directly above it.
When done, we applied water and found that 5 of my 50+ solder joints were bad. One drip and 4 sprays.
We turned off the water, opened at the closest point to clear the lines and then re-soldered WITHOUT pulling the fittings off. In ALL cases, the flux was still active and it sucked the solder in to the point of a drip under the pipe.
I then read later that this is not the way to do this. I should have removed the fittings and started over.
SO…
After 48 hours, the pipes are holding under full pressure, which I think is a 100 PSI city line.
Help me to sleep at night by telling me that I have nothing to worry about in the future. Or…if I do, please let me know and I will go re-solder those connections.
Appreciate the response.
Thanks!
Ron
Have confidence in copper sweat joints that were repaired without disassembly
copper
Related Solutions
The main problem, if any, assuming the solder band is complete and without flaws or gaps is if there's too much solder on the pipe and you cannot insert it into the fitting. The pipe is "tinned" or coated with solder, and there's nothing wrong with that.
The usual approach to making sure that the coating is thin enough is to wipe it down (while the solder is molten) with a rag - easiest if done when you heat it up to take it apart, but you can heat it up again and do that if the fitting won't seat properly as it is. That should leave it thin and nearly mirror-shiny, which is what you want. Caution is needed as you are dealing with hot, molten metal.
The basic secrets of soldering are that things should be physically clean (shiny metal) chemically clean (use appropriate flux) and not overheated (too much heat burns off the flux and solder won't wet the newly-oxidized surfaces.) The silvery solder is perfectly fine shiny metal. Dull gray solder needs to be cleaned up, but there's no need to go to copper.
The pipe must be cleaned until it is bright. A wire brush may not do the job well enough; I use a cloth-backed sand paper (aka emery cloth) for the job. It is about 1.5 inches wide and comes on a roll several feet long. I'm not a plumber but I use it routinely -- for your occasional or one-time use regular paper-backed sand paper would be fine as well. Maybe 80 grit or so.
Overheating the pipe is every bit as troublesome as underheating the pipe. If it gets overheated you may need to let it cool, then sand it and attempt again.
Make sure the socket of the fitting is clean too (and also not previously overheated). These are harder to clean well!
Open the gas valve on the torch so there's plenty of flame. It should make a good bit of noise and throw a tight blue cone of flame maybe 3-4 inches long.
I like to straighten out about 4 inches of solder from the roll, apply flux to both parts of the joint, assemble, and then hold the flame steady on one side of the pipe while occasionally touching the tip of the solder to the opposite side of the pipe. In other words, keep the solder away from direct exposure to the flame. When the pipe is hot enough to melt the solder remove the flame and continue applying droplets of solder into the joint. Add more heat only if the solder stops flowing before it has wicked all the way around the joint.
The truth is I've never used MAPP. Propane has always worked just fine for me. The torch head may make a difference though. I use a Victor TurboTorch similar to below. Been a long time since I watched a Bernzomatic torch burning but I think the TurboTorch makes a wider/larger flame. (image credit: manufacturer, www.esabna.com)
Best Answer
The best long term way to repair a leak is to remove the fitting and stuff some white bread with no crust into the pipe ends to keep the moisture away from the fitting. The reason most folks disassemble is to dry the line (the white bread in my case). If moisture was in the joint you may have sealed it up but there may be a bubble that is a weak point.
In one of my own houses I totally missed one elbow. I had the water on for over 24 hours until it blew apart. It held that long without dripping by just flux. So a possible bad joint may hold for a few years before leaking if it ever will is a guess but I would want to make sure there is a good seal before closing up the walls., edit: I thought I should explain better on the white bread if there is any moisture in the pipe the steam can cause a weak joint, I stuff the pipe on both side with white bread, after soldering I remove the airator on the closest faucet and run the water until the dissolved bread has been flushed out then cycle the valve a few times to make sure everything is out of the line after this is done put the airator back on.