Bundy Lines

I've not heated lines before but I have found several things that help...

Tool quality varies dramatically. Buy or rent a quality tool.

Scuff the tubing with some 120 grit sandpaper before mounting the tool.

Chamfer the end to be flared with a mill file. Break the cut edge of the tube lightly.

Be sure the tool clamps on both sides of the tube. High clamp pressure is essential.

Once the tube is mounted, rotate the tool around the tube several times. This essentially "threads" the tube to the tool teeth and prevents it from slipping.

Practice, practice, practice...

Hope that helps.

Does anyone have a idea whether or not heating bundy lines before attempting the double flair is a good thing or a bad thing? Seems my flaring tool keeps slipping, but if I put a little heat on it things work well. I'm just worried about possible weakening or annealing of the metal.

Best,

Pat Barry

Pat
I agree with Neal buy a high quality flaring tool.I have completed all my double flares using the instructions which are
1/ Chamfer end of pipe with file or grinder.
2/ Fit pipe to clamp using back end of mandrel for height.
3/ tighten clamp nearest pipe first.
4/make first flare(should bell the pipe)
5/Remove mandrel and make 2nd flare.

I found with the cheap tool I first purchased, the pipe pushed through while trying to do the first flare.There were 3 reasons 1/ no instructions
2/ no chamfer
3/ poor pipe grip by the clamp
You'll be pleased to know the high quality
tool was made in the USA.
Ross