ANOTHER BrAzInG question.

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First off I apologize if this is a repeat. I was watching a re-run of Cafe Racer TV on the Velocity network. These guys from the U.K. were building a racing frame for a Norton. They showed one of the guys welding up the frame with O/A. He was using brazing rod and produced beautiful welds. In fact all the frames that leave this shop are assembled in this manner. I'm totally intrigued by this method which makes me wonder the "what & how" is this done.  What kind of rod? Was flux used? Does it have to be used? Does it still have the capillary action like "normal" brazing? Here is the website and the pics of the frame can be seen in the gallery section and the clicking on the workshop tour. http://www.minnovationracing.co.uk/http://www.minnovationracing.co.uk/1..._Workshop_Tour Anyone ever done this? Do you have pics woth sharing? I'm blown away by this for no apparent reason.
Reply:Yes you need flux, done right the filler will be drawn through the joint by capillary action but obviously a welding type joint means you need to build up a fillet to get enough surface area for the joint to work hence the technique being known as either 'bronze welding' or 'fillet brazing' although fillet brazing often refers to a slightly different technique more common to the bicycle world where the goal is a smooth ripple free fillet for a 'seamless look'Normal brazing wires can be used, a fairly common choice would be one of the higher strength flavours containing nickel... often known as sifbronze #2 in the UK which is a trade name for AWS RBCuZn-D. Another suspect is sifbronze 101 which is a proprietary wire based on RBCuZn-A with a little manganese and tin. Gas fluxers are ideal for this sort of work if you do enough to justify their cost
Reply:To me thats amazing. I'm constantly impressed with what I see on this forum. I have a Lincoln 180c , Purox w200 aircraft torch and 2 Dillon MK3's. I like the Lincoln ,but want to get proficient in O/A welding. Thank you for the video. Do you think the rod itself is getting rolled  in flux or just the tip of it?
Reply:They're using a gas fluxer in the vid... http://www.plasmatech.co.uk/page/gas-flux-systems and http://www.gasflux.com/equipment.html. Dunno about the States but they're 'kin spendy in the UK and i really miss having use of one but don't do enough brazing work to justify the costAnother youtube vid by the same user where the green tinge to the flame from the gas flux is more noticable... ETA the filler wires are different (typically CuSi3Mn / AWS RCuSi but there are a few other suspects) but you can 'bronze weld' with MIG and TIG... more commonly known as MIG or TIG brazing, no flux is needed but it doesn't wet out the same/as well as with oxyfuel however it lends itself to some sheetmetal work well.Last edited by hotrodder; 11-25-2012 at 10:23 PM.
Reply:Originally Posted by pipehack....Does it still have the capillary action like "normal" brazing?...
Reply:So.... Would I NOT be able to braze/weld without the use of gas flux? If I have that or any of this right.?.            Those are fabulous looking.
Reply:Flux may be applied with the gas if you have the equipment for it, more commonly you would either buy brazing rods with a pre-applied layer of flux or dip the plain brazing rod in powdered flux.Apparantly "20 mule team Borax" is a cheap half descent brazing flux for brass brazing rods. Never tried it, can't buy it here and the brazing rods I've bought already have a flux coating so I shouldn't need additional flux.
Reply:Originally Posted by pipehackSo.... Would I NOT be able to braze/weld without the use of gas flux? If I have that or any of this right.?.            Those are fabulous looking.
Reply:Originally Posted by pipehackSo.... Would I NOT be able to braze/weld without the use of gas flux? If I have that or any of this right.?.            Those are fabulous looking.
Reply:I believe all the Rickman "Metisse" frames were brazed.  Beautiful bikes they were.  I briefly rode a new Rickman MX bike that had a 250cc Montesa engine.http://en.wikipedia.org/wiki/Rickman_Motorcycles"USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder