Where I got 'em: https://smile.amazon.com/gp/product/B00012Y0FS/
What I used 'em on: https://grassrootsmotorsports.com/forum/grm/ls-headed-300-brainstorming-problems/178791/page4/#post3227591
Thoughts: Primary thought, these are not for use on any 3D surface. A slight curve like you can see below is fine, but as soon as you start trying to braze the vertical surfaces everything runs down to where you just brazed. If you turn the workpiece so that you're brazing on a horizontal surface, everything from your new vertical surface runs down to it. Like water, its going to seek the lowest possible level. When you turn it over to work the other side, you find out that heating the workpiece caused all the brazing fluid on the other side to run down to the lowest part of the piece. So, starting like I did on the inside of the valve cover, when I tried to work on the outer side I found everything had drained down.
Unlike steel brazing with bronze rods, the material doesn't flow into gaps, it only sits on the surface. This, combined with everything above means that you can finish working on both sides and find that its all gone pear shaped and all your work on the inside is for naught because its all drained away from the cut you were trying to braze
Post-work thoughts: Working the material after is pretty much the same as aluminum. Judging by my work with a file, it feels like it is a little harder than aluminum to remove. The edges of the work where it may have been a bit colder doesn't adhere quite as well as where the workpiece was properly hot. It peels up when you take a sander to it which could indicate bad things if you don't take care of it, however once you remove it back to where it was hot it is good and solid.
Post work cleaning:
