Hello all.  I currently have a gas forge set up with a 5/16's steel brake line with a .35 MIG tip that I soldered into place.  Although this seems to work just fine I am looking at switching to a 1/8  pipe nipple that I will be brazing a MIG tip into as it seems a bit more heavy duty and will tolerate being moved around much better than the brake line.  

   My question is I am looking for a low temp Brazing rod that can be utilized with a propane torch as I do not have a O/A set up.  Does such a rod exist?  I've been looking on google and most all were unclear if I could use a simple propane torch. All help would be greatly appreciated. 

Senator

 

I may not be able to answer your question, but I can offer some information. Proprietary brazing rods of brass are alloyed to melt at about 1600F. On steel, this would appear as bright red incandescence. For lower temperature soldering, you might check out silver solder and some of the lead free alloyed solders.

As your mig tip is copper i would suggest sodder. Otherwise you risk melting the tip (brass melts at a lower temp and you can brase copper with brass but it is a nerro margin)

Silver is the way you'd go.  Solder has a melting point from 500-900.  You'd run the risk of loosing your tip from the heat of the forge (usually at shut down).  Silver (45 or 56) brazes at 1200f and the residual heat shouldn't cause any problems.  Your set up should be able to do it unless the pipe is to thick.  Brazing is tricky, practice before applying.  I usually will heat the base metal up, apply the flux then bring to temp then put the small part in place re-flux then apply the silver. 

J, how would you handle a threaded part? Usualy we tap the 1/8" squedual 80 to acomidate the tweco tip. Im willing to risk singed fingers if its beter to heat and flux the pipe then thread in the tip if it is a beter way. I usualy just flux the treads, wrap the base with soder and install, bring to temp, and ad a scose more soder

Charles, that's pretty much the way I suggest.  Since all of my brazing is done with an oxy/ac rig and I'm too lazy to use the proper tips I always preheat the base metal.  A pair of pliers will keep one from singing those fingers.  :o

Threaded schedule 80 is the way to go. You can order say 8'' nipples easily from Mcmaster Carr, part them in the middle and then you have two 4'' threaded units that are easily tapped for your mig tip(s).............  http://www.mcmaster.com/#4550K124

With the price of accetalien might have to use my gasser next time, lol

I drilled and tapped the end of a pipe cap 1/4-28, many MIG tips have this thread. If I want to go bigger or smaller holes in the Mig tip, I just unscrew it and install another one...

instead of a mig tip, use a 1/8 pipe cap, drill the center with a # 67 ( .032") drill bit.    voila home made gas orifice.

That works to Ironsmith but I dont find it as clean looking or as convieniant wile I'm dialing it the burner