I have been wondering what to use on these new aluminum coils.
I assume you have personally used dura fix? Is this the best way?
I haven't used it to repair a leaking system yet, I just wanted to have something available for the inevitable.
I first found out about it a couple of years ago while surfing YouTube videos on aluminum soldering, and was intrigued by a demo of it where a guy was able to solder 2 aluminum cans together with it, and patch some quite large holes in a regular coke can.
I've tried it out on some pieces of aluminum tubing I cut off a scrap Trane condenser, as well as some small aluminum parts to test it out.
The material, and its bond to the aluminum, are both stronger than the aluminum itself.
The key, like with any aluminum soldering, is to get the surface as clean as possible, make a little puddle of the solder material, then scrub through the puddle with the SS brush to break up the oxidation layer to tin the raw aluminum surface with solder, otherwise you are just sticking it to the oxidation layer.
The surface of raw aluminum oxidizes almost as fast as you can scrub the oxidation layer off of it, which is why soldering aluminum is "hard" to do.
If you scrub make a small puddle of the solder, then scrub the aluminum through the puddle, the solder sticks to the raw aluminum before it can oxidize.
with regular aluminum soldering, to cover anything larger than a tiny pinhole, you would have to tin the area being repaired with solder, and tin some solder onto a patch, then solder the patch over the area being repaired.
With Durafix, you can bridge some fairly large holes with it, and once you get it to stick to the raw aluminum, you can build up the thickness as much as you want, and it is stronger than the base metal, so no need for the added patch.
There are a ton of demonstration videos of it on YouTube.
If more government is the answer, then it's a really stupid question.