Another question

[buff]

Is it possible to braze using a tig torch as a heat source ?

 

[madkayaker]

yes its called TIG welding . What you planing

 

[Paul.]

Tig brazing actually!, you need a silcon bronze filler rod, no flux, don't try it with brazing rods designed for oxy acetylene as they contain zinc, Its a DC process and needs a bit of a knack to melt the rod without melting the parent material.

 

[madkayaker]

sounds fun what would you use it on? Will it work on ali?

 

[Paul.]

No not for ally!, you'll have to learn to tig weld with a real welder if you're ever gonna build that canoe,... er sorry kayak

 

[madkayaker]

no its a canoe

 

[Hitch]

Tig, using silicon bronze,copper silicon, aluminium silicon rods, is brazing.Different rods for different jobs, silicon bronze is the most common for brazing id say.
Have a look at SIF for rod selection

 

[Shox Dr]

Just bought some 1.6mm No8 Sifbronze. For a project I'll hopefully start next winter

Do you need to soften the arc Bigger tungsten, Blunt tip?

 

[buff]

Im making a new tank for my bike, but want to add braze on the inside of the welds for added piece of mind. Contacted my local steel stockist last week about the price of sif rods, and the quoted me nearly £50 for a 1kg pack

 

[JW240]

I have tried tig brazing and it is a nice process. takes some practice, im not really used to it.

1kg of Esab tig brazing rods is 25 euro here......

 

[Shox Dr]

I received the 1.6mm Sifbronze No8 today, had a bit of a play at dinnertime. Very easy to use, makes a lovely bead. I'm just home now so I'll have a bit of a look at it tonight

 

[Blackjack]

Im making a new tank for my bike, but want to add braze on the inside of the welds for added piece of mind. Contacted my local steel stockist last week about the price of sif rods, and the quoted me nearly £50 for a 1kg pack

Solder.

 

[buff]

As in a gas soldering iron and solder

 

[Blackjack]

Well, if you want.

But, solder paint on the seam and warm it up with a blowtorch seems like less hassle.

Since you have to make the top and then weld the tunnel (or base) into the tank, none of this is any good anyway as you can't have the braze (solder, whatever) where you weld the tunnel in. Which is where its most likely to leak...

It's easy enough to TIG up any pinholes, simple water testing usually does the trick for finding them. But it you have a pinhole and the back is brazed or even soldered, good luck with trying to seal that up with a TIG torch.

Alternatively, there's things like POR 15 and other tank sealers on the market that are designed for just this eventualtity.

 

[Shox Dr]

I had a play last night and cut though the weld today, there was porosity in some of the weld, I suspected this as you could hear the Rod (braze) boiling with the set at around 45/50Amps.

So I have another go but with a bit of pulse on, this made a big difference.
Still needs some fine tuning

The tube is 32x2.35mm CFS360 NBK you can see where I reused the bits I cut through.

Pulse Amps 50
Base Amps 18
180 Hz
.4sec Pulse Width
1.6mm Red
15CFM



suggestions comments please

 

[Shox Dr]

here they are again cleaned up with some acid

 

[buff]

So do you get the metal orange, then add the rod to it ?

 

[Shox Dr]

It's hard to tell with a hood on, I treated it a bit like solder, in that the rod would melt/flow when it touched the tube, I just kept upping the amps until I was happy with what I was seeing, and that was the open tube was starting to just wetup, at this point the main tube would take the rod, I need to cut these apart and do a few tests on them before I'm happy that I've got it right, and the joint is strong.

I was hoping Hotrodder, Blackjack to name a couple might have commented. There's very little info out there regarding this process

 

[Paul.]

It looks like you've got it about right, well done, the heat in the plate is what melts the rod, the trick as you have found is melting the rod without boiling it, and without melting the parent material, I had to make a load of plaques for a local artist, steel plates with latin wording machined in with the cnc mill, then the letters filled in with bronze, after welding the plate was flash ground to clean up, thats when your imperfections show up..