I started sweating copper pipes today in my new bathroom.I was using solder and flux from a kit I bought last year. The flux was Oatey #95, tinning flux. I couldn't make a good looking joint to save my life. Pipe turned kinda dark, no way to get a pretty solder fillet at the joint. I had the same problem when the stuff was new. On the way to Home Depot, I ran into my plumber neighbor. Mentioned it to him. He said "You're using paste, right? Oatey #5?" So, I bought some #5. Holy cow! #5 made all the difference. So, what's the #95 good for?