Flowflex B270.40 Click Fix, Burst Pipe Soldered Repair Patch, Set of 5 Pieces, Copper/Brass, 22mm

I ordered these to patch a hole in a vertical copper pipe buried in concrete. I chipped out an area large enough to place the patch. I decided to try testing one on another piece of new pipe oriented vertically before I tried the real patch. I cleaned everything up properly and applied flux. Despite directing the heat on the pipe above the fitting, I could not get the solder to appear at the upper edge of the fitting. Without that, how do you know that the solder properly wicked upward? I tested the test pipe. It leaked. These things might work in a horizontal application, but they are not reliable at all in a vertical orientation. Gravity works against you. I had to chip out the concrete completely to remove one end of the pipe and make a proper repair. These things are also very thin compared to standard fittings.