I gave Just For Copper a shot because the idea of no flame for redoing my radiant heat system made sense for where I was working. I put all the lines together and initially had 1 leak which was expected for how that joint went together. I fixed it and there were no leaks for about a week. Now 2 weeks later nearly half of the joints have started seeping. I was careful to sand everything very well and not wipe the sanding dust. I was not stingy with the product and generally had plenty of excess upon installation. It looked great for a week, now I wish I had just soldered it. Now it will take me an additional 1-2 days to repair all the leaks that have started. I would not recommend this product to anyone, and I will never use it again. The worst part, they only way to fix a leak with this stuff is to take it apart and try again, at least with solder you can work on it assembled.