When we cut piping with a tubing cutter it leaves a ridge inside the pipe at the cut edge. This causes turbulence which restricts water flow and can lead to pin-holes in the piping. Deburring is a code requirement.

Usually on tubing cutters there is a knife edge to do this or you can buy a separate tool. A box knife will kind of work as will a round file. If you cut with a hacksaw you do not get this edge.

I see. Does a wire brush used inside the pipe accomplish the same thing? How does that cause pinhole leaks?

The ridge is too hard for a wire brush to knock it off. The ridge causes turbulence by directing the water inward/upward against the inside of the pipe. The pin holes show up in the first few inches from a fitting. The copper institute has some pictures showing water movement in a pipe.

Thanks a lot Lonny, that is very instructive!

I have found that a pocket knife with a small blade is very good for de-burring the copper pipe and I prefer it to the blade on the cutter. An yes, you do need to sharpen the blade more often when cutting the copper.

:o)

JMHO

Carl

Thanks for the replies. One other question, does it help or hurt to use a wire brush on the inside of the pipe after deburring?

There is no impact on cleaning the inside of the pipe. Do it if you feel it contributes to your work.

Thanks Lenny! It just seems to help my untrained eyes so I can be certain I have gotten the burr smoothed out. You are a great help, I can see I would have been in serious trouble if I had not gotten this issue clarified.

I found a great deburring tool made by Brasscraft, it's very handy and comes with an extra blade.