:shrug: Either an old batch or something with your method (hard to tell without watching). The part about "more paste stuff burning off than metal melting" sounds like something amiss for sure. The paste does contain a mild flux, but it shouldn't "burn". And the metal in the paste should melt and flow. (you weren't applying the flame directly to the paste were you?)

No I tried it just like regular solder, letting the material do the melting. Maybe the mixture seperated over time or something. Might just be the way I am doing it, but if that is so then they need to redo the directions.:D If it wasn't $6 a tube I would try it again with a new one.

jaydee116

I have done soldering using a flux called "Kapp Comet Flux" from Kapp Alloy and Wire INC. (814-676-0613)

This is a liquid high temp liquid flux that is used on any metal except aluminum. I have used it to adjust the trigger travel on the Colt 45 ACP where it was necessary to solder steel shims of .010 to .025 inches on the back of the trigger hoop. (Another hobby!) This stuff works great.

I also used it to flux the copper pipes when I built my water cool system, first time I used this flux on copper. It works better than any flux I have used before for copper. Stuff doesn't go up in smoke. My bottle states a temp rating of 350 F- 500F working temps. In the latest Brownells catalog (where I purchased this flux) the spec's rate this stuff at 600F to 800F, so possibly an improvement. Since you are soldering such a mass, I think this stuff may do it for you. I would tin both pieces first after cleaning and fluxing, then flux again and solder around the perimeter after heating the block throughly.

Brownell's web address is www.brownells.com (part # 478-100-100), not cheap $17.40 a bottle but cheap is cheap.
Jim