Quote:
Originally Posted by SparkyAZ
- are there any issues with using a small amount of teflon pipe seal compound (pipe dope goo) on the threads of the flare fitting? And by this, I mean on the male threads only so it gets pushed back and away from the fitting by the compression nut, and only a small amount such that it doesn't contaminate the flare face or get inside the fitting.
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Yes. Don't do it.
Nylog is made from refrigeration oil. Blue is synthetic, Red is mineral. You have no idea what the carrier is for the Teflon goop, and what it might do when it contacts refrigerant.
A flare joint is based on the compression joint between the copper and the brass. Just put a drop of oil on the back of the flare to stop the copper binding on the flare nut and call it good.
I've done *loads* of bum flares that leaked. I showed a couple of them to a local refrigeration guy to get his take on it and he pointed out my very obvious mistake. I was not properly and completely de-burring the end of the tube prior to making the flare, so the seal was between the brass fitting and the rolled edge of the tube rather than the flare face.
This had a two aspect cause. One, I was over-tightening the tubing cutter to get the tube cut quickly. This compressed the end of the tube. Two, the resulting burr was not being completely cut away because of the way I was using the tool.
Since I learned to properly cut and de-burr the tube my flares have been textbook.
Yellowjacket have some great videos on using their tools.
Download and watch this video a couple of times. By the end of it you'll be making tight flares.
Tubing Tools Techniques Training Video - YELLOW JACKET UNIVERSITY
I use a drop of oil on the back of the flare, and I also use a drop of oil on the flare tool when I'm making the flare. That's all.
I have both types of nylog, and nylog will help seal a bum flare. The problem is over time it eventually leaches out of the joint and the flare leaks. I'd rather have it leak *now* than later.