RCMFMaxxMan
RCC Addict
I've been down this road too. Eventually I will get a tig welder when I have a garage and the money and time to practice, but for now, a MAPP gas torch and Harris-56 (as badhoopty mentioned) works for me. The reasons people here are brazing instead of welding are: space, initial investment, and for the small work we do, it is a much gentler learning curve to get a nice, clean joint.
None of the solders you have are meant for what we are trying to do here. The first choice: get some flux-coated bronze brazing rod as makya mentioned. Bernzomatic has some at Home Depot in the welding section I believe, but I think you need an oxygen tank to get the flame hot enough. I could be wrong on that though. I just haven't tried. If you are going to go that route, do not buy the cheap oxy torch from Bernzomatic. It is garbage and you'll waste your money on disposable tank after disposable tank of oxygen. You'll have to ask someone else about torch recommendations though. The second choice is silver solder and the appropriate flux that goes with it. It must be at least 45% silver. I use the 56% from Harris and the Stay-Silv flux. It flows really nicely, it is more silvery in color than lower silver contents, and is very strong when done right. The downside is the cost adds up in the long run, but if you are using it properly, you can do a lot of work with a 1 oz roll. I could describe how to use it, but there are lots of good videos out there. Here's a quick one just showing you what the metal and flux look like when it's the right temperature and how the solder should flow. Note: he's using a flux coated rod. I use the bare coil and brush the flux paste on the joint before heating. Everything else after he applies the flux looks identical to my process, i.e. the flux has melted and looks glossy/greasy and the metal has just started to get a dull blush tone.
https://www.youtube.com/watch?v=XUF0xgAtm2Q
Another tip, a tight fitting joint is key, because the flow of the solder depends on capillary action. Also, surface area is what gives brazing it's strength. Lastly, the metal should be clean. For some reason, sandpaper doesn't work for me on the stainless steel that I use. I think the aluminum oxide contaminates the surface because even if the workpiece looks clean after sanding, it oxidizes before it even gets to the right temperature. Instead, I use a file or grinder or nothing at all if the metal is already clean (stainless is already pretty clean off the shelf).
None of the solders you have are meant for what we are trying to do here. The first choice: get some flux-coated bronze brazing rod as makya mentioned. Bernzomatic has some at Home Depot in the welding section I believe, but I think you need an oxygen tank to get the flame hot enough. I could be wrong on that though. I just haven't tried. If you are going to go that route, do not buy the cheap oxy torch from Bernzomatic. It is garbage and you'll waste your money on disposable tank after disposable tank of oxygen. You'll have to ask someone else about torch recommendations though. The second choice is silver solder and the appropriate flux that goes with it. It must be at least 45% silver. I use the 56% from Harris and the Stay-Silv flux. It flows really nicely, it is more silvery in color than lower silver contents, and is very strong when done right. The downside is the cost adds up in the long run, but if you are using it properly, you can do a lot of work with a 1 oz roll. I could describe how to use it, but there are lots of good videos out there. Here's a quick one just showing you what the metal and flux look like when it's the right temperature and how the solder should flow. Note: he's using a flux coated rod. I use the bare coil and brush the flux paste on the joint before heating. Everything else after he applies the flux looks identical to my process, i.e. the flux has melted and looks glossy/greasy and the metal has just started to get a dull blush tone.
https://www.youtube.com/watch?v=XUF0xgAtm2Q
Another tip, a tight fitting joint is key, because the flow of the solder depends on capillary action. Also, surface area is what gives brazing it's strength. Lastly, the metal should be clean. For some reason, sandpaper doesn't work for me on the stainless steel that I use. I think the aluminum oxide contaminates the surface because even if the workpiece looks clean after sanding, it oxidizes before it even gets to the right temperature. Instead, I use a file or grinder or nothing at all if the metal is already clean (stainless is already pretty clean off the shelf).
