Basic Soldering - Shower Installation

This past weekend I converted my two handle shower system to a one handle system. This is my first attempt at installing a new bathroom - shower only with no tub. It took 6 attempts before I got it to the point it would not leak. Just a few questions:

1 - I had to solder close to the new shower assembly. While there is no visible damage, could the heat from the soldering destroy anything?

2 - I bought a 5 foot 1/2 inch copper pipe from Lowe's, and I think most of the problem was attributed to the 1/2 inch pipe not securing holding a joint (i.e 90 degree elbow). I bought a 10 ft one from Home Depot and the fit was much more snug. Is there a rule of thumb for how tight it should be?

1. You can solder into the valve, or into the fittings that screw into the valve, on the bench before you install it. That protects the valve. Of course you would pull out the cartridge before soldering on the valve.

2. I have had much better luck when soldering with a tinning flux such as Oatey 95. Apply it liberally to both the male and female parts after thorough abrasive or wire cleaning.

3. Always apply heat to the external part of the joint; not the tube. I apply heat to the joint on one side until the parts (fitting and tube) are hot enough on the side opposite the flame to melt the solder well. Then withdraw the heat and finish applying the solder all around.

Practice before the real thing.

If you get a leak, then you must be sure to remove all of the water before you resolder the joint.

It probably isn't a problem with a shower valve, but the pipe you are soldering should always be vented to air. Otherwise, the pressure caused by heating the air in the pipe will blow solder out of the joint.

The shower valve should be opened and the o-rings and plastic fittings inside should be removed prior to soldering.

Whenever soldering near a shower valve is unavoidable, I use a cold wet rag draped over the valve and pipe to keep it cool.

The snugness doesn't matter. All 1/2" fittings should go onto 1/2 pipes with relative ease. if they don't and you really gotta jimmyjack it in, then the pipes probably out of round a tad. Trim it and retry.

The key to getting a good connection is cleaning and fluxing properly.

While soldering is not hard it does take practice to know what to look for. The problem that most novices have is that they don't know when to apply the solder. They usually do 1- 3 things wrong that cause a leak.

#1 they don't clean and flux the pipe and fitting right which won't allow the solder to flow and sweat right resulting in a leak.

#2 they don't heat it up enough and the solder does not sweat in right resulting in a leak.

#3 they over heat the fitting and burn off the flux and the solder doesn't sweat right resulting in a leak.

The combination of clean pipe and fitting properly fluxed with the correct amount of heat and applied solder will result in a well soldered joint.

Taking a dry rag and wiping the solder / joint while the solder is still molten Will give you a professional looking job.

Soldering on a few practice joints will teach you a lot.