Hello all! I've been looking around and would like to know what torch set up you guys use and/or which is your favorite. At my old job, we had an acetylene/air setup with some pretty big torch tips, but I quickly adapted and came to like it a lot. Now, at my new position, we use oxy/acetylene with the Smith Little Torch. Ever since I started, I haven't been able to get the hang of it; I keep burning the flux and causing quick oxidation, and my joints have become brittle and easily snap. I know that it's too hot, but when I back up and try to heat it evenly it isn't enough heat. Is this a problem that anyone else has experienced? For those of you who also have a Smith Little Torch, what is your opinion on it?
I'd love to hear about others' experiences with MAPP gas, other oxy/acetylene setups, and especially oxy/hydrogen. Additionally, I'd like to know what kind of surface you braze on - fire brick, charcoal, metal?
You can absolutely silver-braze steel and stainless. Many high-end bicycle frames are silver-brazed. Both materials are more finicky than brass however, and working with them will make you realize what a wonderfully forgiving material brass is to work with. Stainless TIG rod is a great starting point for trying out brazing stainless. It will require you to freshly abrade the surfaces and I then find it helps to immediately flux them to protect them from contamination and oxidation. Joints will fail on stainless if you don't follow its rules, so get some stock and start trying to put it together. Have fun experimenting!
You guys are rockstars! Thank you so much for the info - I will definitely look into those products and see if maybe a different setup would work better. I also had no idea you could braze steel and stainless steel... is the process for that different?
Thanks again guys!
I absolutely understand your situation. I learned on Acetylene-air torches and found I could control the larger flame better than a smaller, hotter, more highly concentrated flame. I just about went mad on the first project where I had to use an Oxy/Acetylene Smith Little Torch, as I kept blowing right past the melting point of the silver and soon it was bubbling or the brass was melting. It's especially difficult on small stock that has little thermal mass and gets to melting point quickly. That said, once you get acclimated to that style torch you can do very precise work with it. I used one while working on the Burke Museum in 2019 and really appreciated the powerful fine flame. It's great for brazing stainless steel.
Over the years I've worked a lot with Bernzomatic style MAPP gas plumbing torches and learned to do all levels of work with them. I liked that I could travel with the torch head and buy gas at any hardware store. I would usually have two and would do bigger mounts by using both at once, and could silver braze 1/4" steel that way. They can be ungainly so we started using a hose to connect torch head to tank and it helped a lot.
A few years ago I bought a MECO Midget torch and love it. I use Oxygen/Propane instead of Oxygen/Acetylene as it has plenty of power, but things happen just a little more slowly. It is larger than a Little Torch, but still a small handpiece that is easy to use. I also prefer to not have an acetylene cylinder on-site for reasons of cost, safety, and ease of filling. You need to specify the tips for the intended fuel as the acetylene and propane tips are different.
Lately, I've also used an EZ Torch AKA Orca Torch with MAPP gas and find it one of my favorite torches for mountmaking. I like that you can buy it set up for using regular propane/MAPP gas cylinders and that they last a long time. My biggest complaint is that the hose seems to produce a gummy residue in response to the MAPP gas being in it during storage, so it is important to fully drain the hose after each session and I even disconnect the hose and leave the handpiece valve open. I'm not sure if I can recommend it because of this issue but really like it otherwise.
I haven't used Hydrogen as a fuel, but MoPOP had a setup for flame polishing plex and it needed its own exhaust system and special sensors. I've not gotten the impression that the hydrogen "water torch" units sold by Rio Grande have the power for brass work of any major size, but don't have any real experience to base that on.
For Flux, I use Harris Stay-Silv white flux and find it works well but shouldn't be thinned too much and is best applied a little thick. I use Harris Safety-Silv 56 as my main silver brazing alloy and prefer it and their Safety-Silv 45 to jewelry alloys. I haven't found my students having many problems with that flux and alloy system.
I work on soft fire brick as I like that the bricks are cut and not molded, and are thus very flat, square, and uniform size. It also insulates the support surface well and doesn't hold the heat as long as hard brick does. It's not that expensive and lasts quite well.
Mini Torch is great for making small mounts but has to be used a little different than a larger welding torch. It comes with a set of tip sizes but other types of tips are available from Jewelry suppliers like Rio Grande.
What kind of flux are you using? I usually use Dandix flux with the Smith Mini Torch for silver brazing.
My advice is to keep the torch tip moving, as you work, in a circular motion over the area you need to heat, and watch the color of the metal as it gets hotter and hotter. Both the different size tips and the small dials on the torch let you adjust the heat. In addition you can also make adjustments by moving the torch tip closer or further away from the metal. Become very familiar with what the metal looks like just before it melts. Watch closely as the metal becomes shinny and changes color. Practice a lot on different thicknesses of metal. For very small mounts the Smith Mini Torch is great for controlling the heat in small spaces. It takes some practice but is well worth the effort.
Also, I usually work on a metal table with a top covered in fire bricks. I have found that Menard's hardware stores sell a box of replacement fire bricks for stoves at a good price.