For one reason or another I have to make a lot of copper tubing. I've always liked the traditional oil based flux and wasn't keen on any of the water soluble fluxes. But I tried and I'm so glad I did. He is a pleasure to work with and I wish I had known 20 years ago! I will never use any other flux again! It contains (lead-free) solder powder, so you get a pre-tinning with cleaning and fluxing action. The last job I did was 50 solder joints - none of them leaking. If you're a hobbyist, you'llβ¦