Friday, November 16, 2007

Cutting and soldering copper pipe



The last time I had to do his was to repair a supply line going to a bathroom sink. This is an easy task. Once you have done it, you never forget the technique.


Propane Torch and fuel cannister
Tube cutter
Solder flux
Emery Cloth, sandpaper, or steel wool
Wire fitting brush
Tape Measure
Leather Work Gloves
a "Sharpie" for marking the pipe


Here's how to connect a length of copper pipe to an elbow, a "T" or any other copper fitting. Thee are two types of tube cutters. Both have two rotating cutting wheels between an adjustable jaw. The larger cutter has a handle and a de-burring blade behind the adjustable jaw. The smaller cutter doesn't have a handle, and it spins around the pipe to cut by turning it with your finger tips. The smaller cutter is perfect when removing old pipe in close quarters.

Step 1: Measure to length and mark the spot where the pipe is to be cut. If you are cutting near the end of a pipe, you generally need at least one inch of pipe sticking out from your mark on the shortest side of the pipe.
Open the tube cutter until it fits around the pipe. Put the cutting edges of the cutter around the pipe, and screw the knob on the cutter closed until the cutting wheels touch the pipe on the line you have marked. Do not over tighten. It just needs to be tight enough to lightly score the pipe as you turn the cutter on the first couple of passes.

Don't over tighten the cutter as you readjust the cutting wheels and tighten them to make the cuts deeper because you will deform and flare in the ends of the pipe to a smaller size.

There will be some burrs inside of the pipe left from the cutting action. If you have the bigger tube cutter with the handle, put the point of the de-burring blade into the pipe and turn it. The edges of the blade will take off the burrs. If you have the smaller cutter without the de-burring blade, use a file or a reamer.

Step 2: Sand the outside end of the pipe to be soldered with an emery cloth. Building supply stores sell small rolls of emery cloth that are designed for this use. You can also use sandpaper or steel wool. Buff the end until the dull finish of the pipe is brightened. Sand an area that is about one half inch linger than the fitting it will go into.

Hold the fitting that the pipe will be soldered into in one hand, and with the other hand, use a wire fitting brush, emery cloth, or fine sandpaper and buff the inside of the fitting where the pipe slips in until you have sanded the copper inside the fitting to a bright copper color.

Open the flux can and use the small brush that came with it to brush on an even coating of flux to both the inside of the fitting and the outside end of the pipe. Soldering without flux use is impossible.

Put your gloves on and push the pipe to be soldered into the fitting. Twisting it slightly will spread the flux evenly.

Put the propane flame on the pipe and fitting and apply heat as evenly as possible.
Don't try to apply solder yet. When the pipe and fitting are hot enough to solder, the flux will start to bubble up.

People make the mistake of touching the flame to the solder. This is not the way to melt the solder. Unroll a manageable length of solder from the roll and touch it to the edge of the joint that you are heating. The solder will melt and begin to run into the fitting by convection action. It will be drawn into the joint and seal the joint.

Continue to feed the solder into the joint until a beadlike ring appears around the entire fitting. If solder drips or beads at he joint's bottom, this means that you have applied too much solder.

If you wipe the hot solder on on the joint with a dry cloth immediately after applying it, it will give a professionally done appearance. Wear thick leather gloves when you do this. Unprotected skin will be burned.

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