How do you repair pinhole leaks in copper tube?

Answer 1

It is possible to solder the hole closed but if it is going to be inside a wall or you dont want to worry about it leaking again cut it and solder a union where the hole was. If it is smaller than 1/2 " you can purchase flare fittings and do the same thing.

Answer 2

(I'm not sure what you mean by "return piping", but this is how I fix pinhole leaks in copper pipes - other than by properly replacing them of course.)

Purchase an appropriately sized (inside diameter comparable to the outside diameter of the pipe to be fixed - does not have to be exact) short length of washer hose and some matching hose clamps. Cut the hose to a length a few inches greater than the area with pinhole(s) and slit the hose lengthwise. Make sure the interior of the hose that will go over the leak(s) is clean and smooth. Clean the copper pipe with steel wool and wipe it with a paper towel or clean cloth. Slip the hose over the pipe, positioned so that the leak(s) are not near the slit. Place the clamp(s) over the hose so that they are located directly over the leak(s) with the small gap at the screw location not over the leak. Tighten the clamp(s) until the leak stops, but do not overtighten as it is possible that the pipe could collapse (though I have never had this happen). All of this can be done without depressurizing the system if you don't mind getting wet! No plumber's compound of any kind is required. I have had these repairs last for years, but don't count on it.

(The proper way to fix leaks is to drain the system, cut out the length with the hole(s), and solder in new pipe, or to replace the whole system with modern plastic pipe as I have done. It is also possible to splice plastic pipe into the copper system with couplers made for that purpose.)

(Pinhole leaks can be reduced if you put an acid neutralizing system on your water source, but that will require its own maintenance.)

Answer 3

Easiest and most efficient way I do it is cut the area out and get some couplings and a nipple and sweat it on, or you can try out some epoxy or this putty stuff they sell at supply houses, I used the putty stuff and it did not work so I just sweated some fittings lol, if your not to good with a torch (map gas preferred) use sharkbite *or equivalent* push type fittings, just be sure you clean the pipe where your using the pushtype fittings, I like emery cloth or a wire brush pipe cleaner, anyways hope this helps,

I'm just an apprentice plumber but I do a lot lol,

Drain the pipe of all water, otherwise you will never be able to heat it to solder or braze.

Then, clean up the area around the hole with sand paper, use a tec screw to widen the hole to about 2-3 mm, get some clean copper wire (the type used on loud speakers) and fold the strands to form a copper plug, then force-it tight into the hole, use flux to cover the plug and surrounding, use a blow torch and solder over the copper plug, wait for it to cool down then cut-off any excess wire.