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Chris Stevens
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Did you use Tig brazing rods? They are not the same as those for gas brazing. Silver solder is probably better for joining a bush to steel sleeve anyway.
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Chris Stevens
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Not sure I would have used copper bearing rod for that job? I find phosphor bronze is more suited to brazing dissimilar materials: http://www.weldability-sif.com/media/sif_tips/sif_tips_02_tig_brazing.pdf
Guess it might be possible to silver solder with tig, but probably much easier with a torch.
Guess it might be possible to silver solder with tig, but probably much easier with a torch.
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Chris Stevens
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You run DC for tig brazing unless using aluminum bronze rods, which needs AC. I have found phosphor bronze No 8 works for most things though.
DennisCA
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Yes but it says DC+, usually you run DC- for TIG welding??? Not sure my welder can even be set to DC+, you can switch the ground cable but I dunno if that works, I had it like that the first time I ever tried to TIG and I never got anything but some sputtering that way.
DC+ is a typo or mistake. Not the only example in SIF-weldability guides. DCEP (DC+) is sometimes used for a few more specialist applications but it's not practical for most stuff as about 2/3 of the arcs heat occurs at the +ve electrode so you need a much larger tungsten than normal or it just melts
Lots of zinc results in whitish/light gray 'soot' over everything including the torch and often loads of the stuff floating about in the air as it's volatised and boils out of the material so i'm guessing you had a leaded bronze?
In theory should be possible to silver solder with TIG. There's too much zinc in most flavours of silver solder though so limited choices of wire, they're probably all the even more spendy flavours with higher Ag content(?) and i'd have guessed that it'd be difficult to avoid overheating the wire as the arc is much higher temp than an oxy fuel flame and the heat, as said, is far more focused. I've never tried because silver solder is expensive stuff and i can't believe TIG offers any advantages over oxyfuel
Brass/bronze bushes are usually described/sold as 'oil filled phosphor bronze' or 'sintered bronze'. AIUI they're usually neither and are commonly oil impregnated leaded bronzes or sintered manganese bronze which is actually a brass and has a fair bit of zinc in it. Oil, lead and/or zinc all ruin weldability and brazability, especially with TIG because TIG brazing filler wires all have a melting temp a fair bit higher than oxy fuel wires as they don't have any zinc in them i.e. with TIG brazing the melting point of the filler wires is usually higher than whatever flavour of brass or bronze that part is made from
Lots of zinc results in whitish/light gray 'soot' over everything including the torch and often loads of the stuff floating about in the air as it's volatised and boils out of the material so i'm guessing you had a leaded bronze?
In theory should be possible to silver solder with TIG. There's too much zinc in most flavours of silver solder though so limited choices of wire, they're probably all the even more spendy flavours with higher Ag content(?) and i'd have guessed that it'd be difficult to avoid overheating the wire as the arc is much higher temp than an oxy fuel flame and the heat, as said, is far more focused. I've never tried because silver solder is expensive stuff and i can't believe TIG offers any advantages over oxyfuel
Phosphor bronze is a copper alloy. It's mostly copper with ~ 6 or 7% tin in it
DennisCA
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The soot here was pitch black and it spread all over the side I would attempt to braze on. I'm just redoing the part now with a smaller hole, no need for a bushing really, just a screw hole for a metal vise I am building, just wanted to give it that extra touch since I had the bushing.
I watched a video on YouTube by that guy most on here seem to hate. He was using Tig to silver solder. I decided to try it with lead/tin solder. While I don't know squat about Tig so don't take this as advice but it went very well for me. Since I was already using my welder & had the gas already on & all. It took me 2 seconds to make a solder joint in a small piece. Both pieces were already tinned as it was a wire on the torch of my plasma cutter that had come loose because if a bad joint because I assume they didn't get the large brass head got enough. It allowed me to make the solder connection without heating the whole head. I had a drip of solder that had flattened so I cut a small portion off & used it as foil to wrap the wire pushing it into the slot for it in the brass head. Then I spotted it with an arc & it looks like a great solder joint. Everything followed perfect.
Again usually when I explain something I've done on here I'm told I did it wrong so don't take that as a how to.
Again usually when I explain something I've done on here I'm told I did it wrong so don't take that as a how to.
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Chris Stevens
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Useful info...................the No8 phosphor bronze I have seems to be different to the Al Cu rods, and works better for most of what I use if for.
There's nothing inherently wrong about using a TIG to solder, at the end of the day soldering/brazing/welding just needs a heat source and something to protect and/or actively clean the metal. An open flame, an oven, induction heating or a leccy arc can all provide the former with either a flux or gas shielding for the later
DAPPH
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Your post is interesting Hotrodder , my mind jumped a yard or so out my head .
I'm a new born again beginner ....... with a multi task synergic welder & haven't done much MIG or TIG since my apprenticeship days 50 years ago . )
I have ... Two small 100 gram containers of pink SIF weld , a couple of Kg of ( 3 mm ish ) silicone braze rods & some steel bit's I want to try and play with plus a medium grade flap wheel to clean the surfaces.
By what you have said , may I be able to braze them with TIG DC. ????
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Chris Stevens
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If you want to tig braze, you will need tig brazing rods, which are used without flux.
As said brazing consumables are different for TIG (and MIG) and no flux is needed 'cause the argon keeps the atmosphere away. It all gets confusing because common OA and TIG brazing wires both often get called 'silicon bronze' when they're very different compositions and silicon bronze OA wire is actually a brass (about 60/40 copper/zinc with a tiny bit of silicon). Try and use them with TIG and the large amounts of zinc in them result in a right mess as it boils out
As mentioned earlier in the thread the 2 usual suspects for brazing with TIG (or MIG) are...
CuSi3 (copper, 3% silicon, 1% manganese) which also gets called silicon bronze, goes by tradenames like SIF silcopper #968 and BS something or other C9 for example https://www.google.co.uk/webhp?hl=en#hl=en&q=c9+filler+wire
Phosphor bronze is the other common suspect, CuSn7 aka SIF #8 aka C11
CuSi3 is the cheaper of the two, CuSn7 wets out a little better but neither of them (or the more spendy and less friendly to use aluminium bronzes, Cu with ~10% Al) wet out anywhere near as much as when brazing with oxyfuel... useless for capillary joints, TIG/MIG brazing is more akin to 'bronze welding' / fillet brazing
As mentioned earlier in the thread the 2 usual suspects for brazing with TIG (or MIG) are...
CuSi3 (copper, 3% silicon, 1% manganese) which also gets called silicon bronze, goes by tradenames like SIF silcopper #968 and BS something or other C9 for example https://www.google.co.uk/webhp?hl=en#hl=en&q=c9+filler+wire
Phosphor bronze is the other common suspect, CuSn7 aka SIF #8 aka C11
CuSi3 is the cheaper of the two, CuSn7 wets out a little better but neither of them (or the more spendy and less friendly to use aluminium bronzes, Cu with ~10% Al) wet out anywhere near as much as when brazing with oxyfuel... useless for capillary joints, TIG/MIG brazing is more akin to 'bronze welding' / fillet brazing
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Chris Stevens
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SIF 968 available in small quantities on Ebay, wonder how that compares to No8?
Shox Dr
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I believe it wets out better
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Chris Stevens
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Thats interesting.............. Have some 968 somewhere, so will have to look it out and give it a try. Generally use No8 though, which seems fine for all I do.
DAPPH
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Gents,
Thank you very much for the information about the different rods and also for giving me their classification numbers , I'd have been bankrupted by the time I eventually found the right alloy ratios doing a suck it & see how it works sort of direction.
Dave
Thank you very much for the information about the different rods and also for giving me their classification numbers , I'd have been bankrupted by the time I eventually found the right alloy ratios doing a suck it & see how it works sort of direction.
Dave
