1/2' copper piping plumbing problem.?

I can only suggest that you use a connector with an "olive" and a nut at each end which you fit over the two pipe sections and tighten with a spanner. There is no heat needed and you only need to bury the whole contraption under plaster and I suppose then tiles. I plumbed my whole house with this method. Good Luck

The reason it swells up is because of water turning into steam. This pressure is tremendous. You need to open a valve or faucet near where you are soldering. Try to make you solder joint outside the wall if possible.

If it is not possible do as little soldering in the wall as you can. We solder all the fittings first then put the piece in the wall and just solder the connections.

If you have no other choice then I suggest using compression fittings to fix the water pipe problem. If the application allows you can install an access door where you are working that will allow you to re-access the areas in the future if needed.

Clean the end of the pipe with 'wet and dry' paper or emery cloth. Clean it by going around the pipe, not longitudinally. (that's important). Wipe the cleaned area with a smearing of flux. Apply heat just before the cleaned area, NOT on it otherwise you will quickly cause oxidation. Your torch should be about 60% of it's max. Too hot and the copper will oxidise, too cool and it won't be hot enough to melt the solder. Ensure that you are using the correct melting point solder for the job. Hold the solder in one hand and apply it to the tube, playing the flame on and off and round the pipe. You need to get the heat to just the point where the solder begins to run. As soon as the solder runs, wipe it round with a mole skin cloth. (I use a leather garden glove, it works a treat, I can wipe it round and clean without getting burned leaving the end just silvered. When you have mastered that then you can move on to joining the pipes together with an end solder socket or, if you prefer, a yorkshire soldered socket. If the copper pipe changes color to a light reddish brown then you have applied too much heat. Likewise if the solder runs off like water. You need to get the heat to where the solder is between running off and being plastic.

You have to make sure the pipe is VERY clean, and the insides of the fittings too, before you assemble the pipe. Use a little bit of soldering flux on the connectors before you slide them on the pipe. The slightest bit of grease (or fingerprints) on the pipes will prevent the solder from adhering (this is a chemical reaction), and this might be the source of your problem. Either use steel wool or special wire brushes made for the purpose.

are u sanding the pipe before u try to solder it......u have to sand the outside of the pipe for the solder to hang on it just like sanding a car before u paint it.....also u have to use a flux to help the solder run around ur fitting......sand then flux then solder....make sure all the water is OUT of the line......if u can get a shop vac and suck it out....or try opening a faucet somewhere near that area to drain the pipe down......also u will need to clean the inside of the fitting....thats called a cleaning brush and u can get it at any lowes or home depot...just get the one for ur size pipe....1/2".....after sanding the pipe cleaning the fitting and fluxing the pipe and fitting the solder joint should take with no problem as long as they is no water where u r trying to solder at....good luck

you need to re seal your pipe, one possible reason is you ,didn't heat your pipe up en ought,or second reason , is you didn't use , en ought flux, , re cut it , re join it , make sure it sucks the flux,inside, then re solider the outside around the pipe. , one more thing ,make sure you have a clamp to hold the pipe to the wall, as it mite just be moving on you ,