brazing at home?

For copper or brass, I would recommend Silphos 15. It isn't any good for steel, but is good for copper and copper alloys. It is a lot cheaper than silver solder containing 50% or more silver.

Harbor Freight sells a good propane torch at about half of what Home Depot sells their propane torch. Maybe not any savings if you pay for shipping on just one item.

You can do a lot with a little propane torch that goes on a disposable propane tank. Using some insulating material to keep the heat concentrated is the clue when you are trying to do something that is good sized.

Dan

snipped-for-privacy@hotmail.com (sam annex) wrote in message news:... ...

Hi. I tried the makeshift torch approach, and it did not work well. Maybe others have more patience, but it did not work out well at all for me. First, I thought it was a problem with heat conduction from the brass brazing rod, but this was not the case. The propane flame just didn't give enough heat to melt the rod. This was a Bernzomatic brass rod with a 1620F working temp. I tried a torch design from backyardmetalcasting.com (Lionel Olver design) and it was starved for air, and did not work correctly. There was also a lot of huff and puff, and the thing was not even able to melt brass rod (1/8") without a workpiece. It was able to melt copper wire, or at least oxidize it, so it was not a problem with temperature. It was a problem with heat. This was a waste of time. I needed to get some brazing done, so I bought a used plumber's air acetylene torch with a Prestolite handle. This worked so much better that unless you are absolutely broke, you should really consider this. You can get these torches around here, if you are patient, for about $100.

Now, if you are too broke for this solution, and you really want to fool around (like me), you can try a few other tricks. Note that these did not work for me, but that does not mean that they will work for you.

1) I found an old microwave oven at a garage sale that they were willing to sell me for $3. Now, $3 is pretty easy to come by. It is even within panhandling range. I stripped the oven down to the transformer, and cut the HV secondary off with a hacksaw. Big mistake. Never do that; instead cut the weld and split the transformer with a chisel. The secondary comes right out. I rewound it with #10 wire. Had to spend $5 for some transformer tape, but old grocery bags works almost as well, and you gotta eat. Somebody discarded an old AA carbon zinc battery on the bus, and I stuffed this in my pocket with nobody the wiser. This was used, in conjunction with some old copper water tubing, to make a carbon arc torch. This beast was just the opposite of the weak propane torch. It creates a brush-like violet arc that dances all around. This arc will instantly melt even decent sized mild steel, like old desktop AT cases. The burnthrough is so rapid and uncontrolled that this technique is difficult to use for brazing. Perhaps with a dual carbon torch, and some kind of current limiting, it will work. But, I only found one AA battery on the bus. Try Wal-mart for D and C cells. They are $1 for a pack of four or so. Also, a saltwater resistor might give better results. Don't shock yourself or burn your eyes. To be continued...I haven't given up on this one yet. 2) Others may have had better luck with this other low budget approach. Build a side draft tuyere forge. You need a tuyere. In a moment of weakness, I coughed up $5 for a piece of 1 1/2" pipe. Silly. If you walk around, "Handicapped Parking" signs have just the right sized pipes. I am not encouraging illegal vandalism, but if you are in a bad enough neighborhood, others will have done the dirty work for you and you will be able to surreptitiously sneak off with the precious pipe. No need to fret over the forge body. Just use wood and nail split tin cans over it. Or, if you are lucky, you can find an unguarded construction site where they are putting up HVAC ducting. A quiet mission will result in all the galvanized flashing that you need. Again, I am not advising immorality. Scavange their cutoffs (drops). You will have to protect the forge with refractory. I posted earlier about how to do a low budget refractory using hardpan clay, BBQ ashes, sand, and concrete. Drill some holes with a cheap drill. If you don't have one, you can often buy an old beat up one at a garage sale. Be sure to test it out. People lie. Fore the air blast, use an old hair dryer. Salvation Army sells these for $2, but you can often score a dirty one for $2 during discount days. You need charcoal to fuel the forge. I have found that Kingsford briquettes do not work well, and, besides, they cost money. Here's how to beat the Kingsford charcoal trap. Again, visit that construction site and score some wood scraps. Make sure they are not treated (green, or have little perforations in a regular array). Or, even better, clear some firewood from some busy yuppie who is in too much of a hurry to do it himself. Do not offer to pay, since these greedy bastards will often think that they are doing you a favor, and they will try to chisel some obscene favor or fee out of you. Make sure to get oak, fruitwood or pine. Do not use a toxic wood. Eventually, some yuppie will get tired of fussing with her charcoal grill and just leave it out on the street during trash hauling day. This is when you spring into action. Quietly, liberate the grill. Even if it has bent legs and rusted out vent flaps, it will be useful. Start the wood using some newspaper, twigs, and precious (bought) Kingsford charcoal. A charcoal chimney is useful for this purpose, but it costs $10. You can make your own out of a restaurant sized can, carefully extracted from a dumpster in the back of a restaurant. Discard the lid, and make sure to use a handle, since these starters get red hot when the fires gets going. Dump the flaming mass on the firewood and cook some meat. Especially good are the junk cuts like beef shoulder, since they do well with a hot start, and a dying fire. When the wood starts coaling up real good, eat the meat (hey, you gotta eat, so no fair counting this as part of the cost, besides, cheap cuts of beef are less expensive than frozen pizza). Quench the fire with water and smother it when it looks right. The black squarish lumps are charcoal, and they will produce heat that is much better than Kingsford briquettes. Plus, they are free. Use these in your forge.

I never got this to work. Probably due to lack of control, or uncertainty in brass source. I used a nut off a junk sink fixture that someone threw away. I did not melt, but I am very certain that a charcoal forge can get hot enough to melt brass. To be continued...I haven't given up on this one yet.

I have given up on the stupid big propane torch. Even with firebrick, these don't seem to get hot enough.