How to Prep Copper Pipe for Soldering

Cut, ream, clean and flux copper tube and a solder-cup fitting so solder can fill the joint. Solder does not bridge bad preparation.

What you need

Confirm what the line carries. This is for soldered water joints. Stop for fuel gas or refrigeration lines.
Isolate and drain the line. The joint area must be dry before any heat.
Cut the tube square with a tubing cutter. Advance the wheel in small steps so the end stays round.
Ream the inside fully to remove the burr ridge. Deburr the outside edge lightly without tapering the tube.
Clean the outside of the tube for slightly more than the depth of the fitting cup. Rotate the abrasive around the tube until it is uniformly bright.
Clean the inside of the cup with a fitting brush sized to it. Brush the full circumference and depth.
Wipe away dust. Do not touch cleaned surfaces with bare or oily fingers. Re-clean any surface that gets touched.
Dry-fit to full seating and mark orientation. Brush a thin, even flux film on tube and cup. Never use your finger.

The 46650 stainless mini brush can detail an accessible cup or fitting surface. It is not the main tool for the cup bore.
The 80151 chip brush is narrower for low-volume flux. The 80152 is wider. Check the flux label allows a chip brush.
Break in a new chip brush on scrap and shake out loose bristles. Throw it away after fluxing.
An angled cut can bottom on one side and leave the other short of full overlap. More solder does not fix that.

Soldering is hot work. Clear or shield combustibles, have an extinguisher ready, and ventilate.
Replace a fitting that is overheated, distorted or deeply scored. Cut back a tube end that is oval, crushed or gouged.
Potable water joints need lead-free solder and flux. Check your code for permits and a licensed plumber.

Questions about the right tool for your job? Email cs@hydestore.com or call 508-916-6442.