beginner brazing questions
The rack post has got me very curious about making my own rack. Being mostly a wood worker, I have a few questions.
Being cheap will allow me to hide this project from the wife, so I do not have a lot of money to burn on this idea (no pun intended). I don't need heavy duty equipment as I would stick to racks and not move on to frames. It would also not be a primary hobby, just a couple of small projects.
I have a cheap propane torch Is this too cheap for brazing? http://bernzomatic.com/PRODUCTS/TORC...3/Default.aspx
If it wont work, what is a cheap torch that would work.
I have done an internet search and am having a hard time finding a website that talks about brazing instead of welding. What are good suppliers of brazing rods with actual information about the product.
I figured out where to get the steel already.
You're unlikely to get enough heat to braze with an air/propane torch. Oxy/propane is about the minimum for that. Oxy/acetylene is ideal.
You can use that kind of torch successfully with MAPP gas and braze your rack with silver solder 45%. Silver is a lot more expensive than brass, but it does not take much. I found cheap silver on ebay. Be sure it is something like safetysilv and contains no cadmium.
This level of heat from these torches is really not sufficient, and it requires heating tubing to a much higher heat than would be required with oxy supplemented fuels. It is something of a pradox that the cool fuel requires more heat to work, but that is the way it works, with both welding and brazing. The greater heat can burn the flux, so heat control is dicey. However, the end result seems strong, and 4130 can take the high heat which is basically similar to what would happen with brass brazing.
Attached rack was made of 4130 and used a MAPP gas household venturi type torch. Survived a long tour with no signs of wear.
If you are making a rack for paniers helps to customize the rack to the specific paniers, so start with those, then move onto the rack. The other option is to go for a generic rack if you can't decide on only one kind of panier.
So can anybody recomend a good online supplier. I need to figure how much of an investement is needed to know if this is an expensive dream or a doable concept. I tried doing an online search for brazing equipment and could not find any user-friendly stores/sites.
I envy everyones work and would love to produce something myself.
I'm mostly a woodworker too. That rack was made with 4130 tubing which you can get at aircraft spruce; a standard hand held torch like people use for plumbing, with a MAPP bottle; a 10" Nicholson rat tail file, for 3/8" tubing, match file diameter to the tubing diameter, from hardware store; a Jorgensen clamp on vise since I didn't want this anywhere near my workbench; And the Harris safetysilv stuff that you can get at a local welding supply. Really nothing online involved unless you order from AS online. I made the bender, benders are covered in other threads.
Ebay and cyberweld come quickly to mind. The bad news is that you probably are going to have to spend at least $400 to get an Oxy/Acetylene setup. $170 for tanks and a Victor J100 torch rig for $230. And that isn't an ideal setup. Wish it was cheaper, I'm just getting set back up right now and money is a little tight.
Originally Posted by ncscott
Wait... All MAPP fuel is, is a Bernzomatic branded fuel? Cool... so it can be done cheaply. According to Bernzomatic, that torch I have is purely for propane, so I would have to buy another to use MAPP. The silver would be more expensive, but the money not being spent on an expensive torch would make up for the costs. Unfortunately, the wife just discovered my research, so there is a monkey wrench thrown in my plans.
Thanks for the info,
go to school
Try signing up at a local community college for a basic welding course and try to talk your instructor into making it a class project. The classes usually are very cheap. You'll learn techniques and get to use their equipment.
You can easily braze a rack with a $7 can of mapp from Home Depot and a Bernzomatic torch. I use the Bernzomatic model JTH7 mapp/air torch (it has a hose that makes it more portable) and I have brazed many entire frames with it (yes, even bottom brackets).
See my latest build diary of a long wheelbase recumbent here:
A basic oxy-acetylene torche can be had for about $40 from Home Depot. Can even get hot enough to weld steel if you wanted to. Only issue is the expensive oxygen canisters only last about 15-minutes so you gotta work quickly.
The other issue would be available nozzles for the supplied torch head. Possibly also regulation of pressure, which can be an issue with even lower quality full size regulators.