Flux - 1 Pint

I bought this specifically to tack solder some stainless steel 50-mesh filter screen together. I used 96% tin, 4% silver solder and it worked really well - good flow and wetting. I used both a 140W solder gun and a propane torch. The caveat is whatever heating method you use, you must get the joint plenty hot. The solder gun worked for a small area of about 1/4" diameter but it is difficult to get that to work on a larger area as the heat dissipates out of the joint too fast. The larger areas are better for a torch. Be sure to use plenty of flux and re-apply when hot too. It seems like this bottle will last a long time.

25+ years ago an older gentlemen who ran a professional sheet metal fabrication shop in our town said he would teach me how to solder using large soldering irons and a propane torch after hours one day-- I simply had to show up, keep my mouth shut, and do what he said--his company made anything one could dream of from metal--massive custom copper stove hoods, 10 feet tall stainless steel bird cages, to antique car hoods. Concerning Ruby Fluid flux he said, "Son, you can solder toilet paper to railroad iron using this stuff as long as you first get the surfaces clean, degreased, and then know how to neutralize the flux once you're done." He wasn't lying either. I soldered a lot of expensive sheet brass together back then on a personal project without incident using Ruby Fluid. The joints turned out very professional for a newbie. I am glad to find Ruby Fluid for sale here. It works like magic.

Great flux, a little goes a long way, my solder lines are smooth and fluid. Also noticed little to no smoke when soldering.

It works well for my projects.

I used this flux with 50/50 tin/lead soldering bars to repair a radiator on a fire truck, it was used to solder a brass filler neck to a steel reservoir. I did some experimenting prior to using it on the fire truck by soldering a brass ring to a piece of sheet metal with flux and without, let’s just say the flux did its job perfectly!

It works, but I now only use it for non-PCB applications, because I found out it conducts electricity between PCB pads. I had a sensitive electronic project that was due the next day, and it would not work. After some tinkering, I found the residue fluid was conducting on an amplifier circuit causing bad signals. Cleaned it with alcohol, and it started working! I think there should be note somewhere on the bottle about its conductivity. Now I use it for tinning wire leads in a solder pot, and it works well for that application.

Has much less smoke and smell when soldering. Also easier cleanup.

A tiny amount goes a long way. I'm still on my first syringe of this flux and I probably won't have to buy another can for years. While larger cans of flux like this are targeted toward professional shops, it'll last a lifetime for a home shop. Make sure to clean up the remainder when you're finished, it is acidic and will corrode your circuits over time. I rarely give 5 stars for even items that perform as expected but this item does everything it claims, outperforms more expensive fluxes I've used, and well exceeds my expectations for the price.