TIG Welding Something that is Brazed

Jason H · Apr 25, 2012

This is a steel rule die that is made for me by an outside company. The stresses on the unit cause the brazed portion to crack and then when the die cuts fabric the cracks catch the fabric and cause problems.

I have a Miller 250 Sync, a small OA rig, and a Lincoln Mig set up. I have never brazed in my life, can I just Tig these sections and grind it back out?

Treat me nice, yes I am still green.

atomarc · Apr 25, 2012

My only comment would be you can only use the same filler material that is present now...brass! You can't fill over that material with any other material without removing the original filler completely, and judging from your pictures that would be impossible. I have never used a TIG with brazing rod so I don't know if it would work. I think the flux required with brazing would screw up the tungsten, but then again I don't know for sure.

It's hard to tell size on your pictures but my first choice would be a small oxy-acetlyene tip and some flux covered brazing rod.

Stuart

mfgbydesign · Apr 25, 2012

Technically these joints are "braze welded" as the strength comes from the fillet of filler material rather than capillary action between the faying surfaces. The strength of the joint is limited to the strength of the filler metal if the joint gap exceeds about .004 inches. So yes, you can use GTAW (tig) to reflow the Braze Filler Metal (BFM).
1. Clean the surfaces thouroughly using aluminum oxide (sandpaper). Avoid using "scotch-brite." Follow with isopropyl alcohol.
2. Use low heat, just enough to reflow the BFM. Avoid overheating; the filler metal appears to have zinc and will give off poisonous gas indicated by a boiling action and white smoke.
3. Aviod melting the base metal. You don't want to mix the alloys.

You might consider a mapp gas torch and some Handy flux from the hardware store.

Jason H · Apr 26, 2012

mfgbydesign said:
Technically these joints are "braze welded" as the strength comes from the fillet of filler material rather than capillary action between the faying surfaces. The strength of the joint is limited to the strength of the filler metal if the joint gap exceeds about .004 inches. So yes, you can use GTAW (tig) to reflow the Braze Filler Metal (BFM).
1. Clean the surfaces thouroughly using aluminum oxide (sandpaper). Avoid using "scotch-brite." Follow with isopropyl alcohol.
2. Use low heat, just enough to reflow the BFM. Avoid overheating; the filler metal appears to have zinc and will give off poisonous gas indicated by a boiling action and white smoke.
3. Aviod melting the base metal. You don't want to mix the alloys.

You might consider a mapp gas torch and some Handy flux from the hardware store.

Thanks guys.

Jason

Ries · Apr 26, 2012

Use a silicon bronze filler rod. All the local welding supply stores should be able to sell you a pound of 1/16" filler rod of it. Then, Tig weld with a sharp tungsten, and play the arc on the base metal, very low amps, and feed in brazing rod. I Tig braze almost daily- it allows you to put stuff like this together without melting the parent metal. I would suggest, however, some practice first, on some old steel packing strap- the stuff they strap pallets together with- its almost the same size and thickness as a steel rule die, and you can get the hang of it without melting the die. A light touch is required, and you need to learn how the silly bronze filler flows- it kind of waits a second, then jumps onboard.

adama · Apr 27, 2012

Brazing is probably the only viable option on cutting rules. There often a very high carbon steel and heat treated. What might be a better option for your application if your machine will allow is to look into a proper fabric cutting punch, like used in leather work on a clicker press. There a lot larger steel frame with a cutting edge. There significantly tougher more robust than a std or even brazed up rule die like you have there.

Look at the draws full in the bottom of this add,

For Sale

Heavey Metal · Apr 27, 2012

+1 on the silocone bronze.

Need to fix the problem though

The plywood would appear to be the problem to me need to be stiffer materal

adama · Apr 27, 2012

No ply woods not the issue, its the rules that will flex! Trust me i deal with cutting dies all the time cutting everything from greeting cars right through to leather and hardboard. Forms like that are realy hard on the rule - create a lot of side pressure. The clicker type rules are just way way tougher and get fully welded together.

Jason H · Apr 27, 2012

adama said:
No ply woods not the issue, its the rules that will flex! Trust me i deal with cutting dies all the time cutting everything from greeting cars right through to leather and hardboard. Forms like that are realy hard on the rule - create a lot of side pressure. The clicker type rules are just way way tougher and get fully welded together.

So did the tig brazing as described with the silicone bronze here and worked like a charm. I have tried the forged dies with pinked edge in the past and cost wise it is terrible since they cant be sharpened. All my straight edged items are forged.

Jason

MEF · Apr 29, 2012

I would say find another die maker, I have been cutting paper & plastic with steel rule dies for 25 years and I have never seen an brazed die like that. The cutting rule is high carbon steel that has been heat treated on the cutting side to give a durable edge. Brazing like that will most likely anneal the temper and it will dull in no time flat which will make your problem worse.

What kind of fabric are you cutting? You can request a thicker wood base, but if you are cutting thick stacks of fabric you may need that much stick-out.

If this is a "normal" die for garment type work, you may be trying to cut too many layers at once if the rule is separating at the joins.

Jason H · Apr 30, 2012

MEF said:
I would say find another die maker, I have been cutting paper & plastic with steel rule dies for 25 years and I have never seen an brazed die like that. The cutting rule is high carbon steel that has been heat treated on the cutting side to give a durable edge. Brazing like that will most likely anneal the temper and it will dull in no time flat which will make your problem worse.

What kind of fabric are you cutting? You can request a thicker wood base, but if you are cutting thick stacks of fabric you may need that much stick-out.

If this is a "normal" die for garment type work, you may be trying to cut too many layers at once if the rule is separating at the joins.

Sadly enough the guy that made that was an old timer that had been here in Los Angeles for many years. He passed away in his shop several months ago.

I found a new guy that seems to be on the ball. He only dies the forged dyes and only offers two heights. For the pinked edge my guys always overload them. I try and try to instruct but sure enough someone doesn't listen.

One of the ones I repaired as described here saw about 10 hours of service with no problem. Some areas I had to build up and then grind to shape. what a pain.

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