| Author | Message | ||
     Reepicheep |
Well, I can't afford a welder right now, and am sick of coming up against a dead end whenever I need to join two pieces of metal. So I would like to teach myself brazing. If I look at the math, it looks like propane ought to be able to do it out of the bottle using bronze brazing rods. I have no practical experience in the matter, I just did some googling and reading. Home Depot also has an oxygen / Mapi kit for $50 or so that looks good, and would get about twice the heat out. Tips? Advice? What kind of limits are there to what can be brazed? What other gear should I get (besides heavy gloves and heavy apron)? What's the best surface (cheap) to work against? How to I hold things in place while I am joining them? Thanks! | ||
| Henrik |
MAP gas alone has worked well for me for heating heavy steel rod to a good glow (like for bending my S2 kickstand), so I think MAP alone might do you, depending on material thickness and such. make sure the surfaces you're working on are *clean*, as in squeaky, gleaming, freshly sanded. Otherwise it just won't work. Get good flux as well. I haven't done any brazing while in the US, so I can't give you any brand names to look for. I used to do very simple stuff, and would use heat proof brick/tile, like what you'd use for the inside of a fireplace, to stack up and support the work pieces. Don't use regular brick or stone as it will get brittle and explode into tiny sharp shards when it get's hot - don't ask  C-clamps and vise-grips can be a help as well, as long as you don't mount them close enough to ruin them with the heat. Oh, and you'll need some pliers or vise-grips to hold that rod - it'll get hot - agin, don't ask Keep us posted. Henrik | ||
| Rocketman |
A cheap alternative to flux is Borax. Should be available from any good chemist  Rocket | ||
| Csg_inc |
Please get some welders goggles The lenses are a dark green but check with your local welding gas supplier for a proper recommendation | ||
| Reepicheep |
Welders goggles even for brazing? Really? Does it get that bright? Or just safety glasses? Those I have already. Borax huh? Thanks Rocket. So does a brazed joint hold up as well as a welded joint? Or are they more susceptible to vibration / fatigue? I see specs showing a bronze braze is good for 60,000 psi... I don't know how that compares to a weld, but it sounds pretty dang strong. | ||
| Bluzm2 |
Bill, You should at least get a pair of welding glasses. They are like very dark sunglasses with safety lenses. When the metal is red and the flux is glowing, it's very bright. The dark lenses let you see what you are doing. | ||
| Road_thing |
What Brad said. Unless you really enjoy that big blue spot in front of your eyes for the next couple of hours after you finish with the torch! rt | ||
| Bomber |
Reep -- brazing can be ALMOST as strong as a welded joint -- since yer an electronics maven, brazing can be liked to soldering, in which the two pieces of material are held together by a melted joint of filler metal, where welding is actually melting the pieces together (and may involve no use of filler material at all) get the oxy/map kit -- map alone if pretty good for most things, but the oxy/map will allow you to get enough heat into thicker/bigger pieces of metal -- you'd be surprised at how much heat a couple of pieces of mild steel will soak up without getting hot enough to braze there are a number of different brazing rods, not all of em bronze/brass -- there's nickel, steel, and, wait for it, aluminum, too -- Rocket's right, Borax can be used straight outa the box as a fluxing agent (except with aluminum) -- glasses/goggles aye -- get em, use em -- no doubt at all also useful is a surface on which to work -- if you place the pieces to the brazed on a vice ot something, you'll likely still be standing there next Holloween, waiting for the flux to melt -- refractory bricks (from the local fireplace store) make a good working surface also get a couple of LARGE vice grip type welding clamps -- lil ones soak up enough heat to loos the temper outa the spring any one want a bucnh of lil vicegrips with non-operative springs? (Message edited by bomber on February 21, 2006) | ||
| Road_thing |
...lil vicegrips with non-operative springs... Got plenty, thanks... | ||
| Jackbequick |
Reep - If there is a junior college or something like that in your area that teaches an introductory welding class you would really enjoy taking that. I took one about 15 years ago and learned the basics of stick, oxy-acetylene, and TIG welding without having to make much of an investment (just my personal equipment). It really helped me later in choosing welding processes and also later in acquiring equipment. As a generalization, it is actually easier to weld using too much heat judiciously than it is to try to weld without enough heat available. And those main purpose some of those oxy/mapp "starter" sets seem to serve is to prove what will not work and send you out to look for better equipment. I was doing gunsmithing at the time and eventually wound up with O/A rig, a stick welder, and a TIG welder. If I were only going to own one welding rig it would be my venerable old Miller Thunderbolt AC/DC stick welder (never buy a AC only welder!). And a O/A rig. Oh, and a TIG welder to keep the HAZ as small as possible on some kinds of work. Sigh, so many tools, so little time... Jack | ||
| Xring |
Reep, You have mail. Bill |
