Does Anyone Braze Anymore ??

[MinnesotaDaveChalmers]

I have Brazed some projects but remember compared toweling it is like gluing something together.
Depending on the duty level required it works.

I WAS proficient in Brazing and have always wanted to learn TIG... just need the machine to try it out !

The TIG would replace most any Brazing !

Nice thing about tig is the highly controlled arc - makes tig brazing easier than torch brazing (for me).

I like torch welding, I don't care for torch brazing. Likely because I don't do it - lol.

 

[Ritothebull]

Speaking of TIG brazing, can anybody comment on silver soldering with TIG? I need to connect some copper to steel.

I have some rebar I've welded up to reinforce the foundation & anchors that will eventually be buried in concrete for a HAM radio tower. I need to attach some copper to that rebar for grounding. I have the TIG welder, but no acetylene anything. You need to use high temp silver solder or such as normal solder can melt on you in a lightning strike.

I'm trying to figure out if I can get the job done with my TIG welder or need to beg, borrow or buy some acetylene rig. I've got some appropriate silver solder & flux. I assume I'd need to use at least a bit of argon to keep the tungsten clean. Not sure if the flux would help or hurt.

I've cleaned up the rebar well where things will connect up. Haven't done any testing yet on scraps & looking for advice before I get to that step.

Copper to brass you can just tig braze it pretty easy.

 

[Tractor Seabee]

I have Brazed some projects but remember compared toweling it is like gluing something together.
Depending on the duty level required it works.

I WAS proficient in Brazing and have always wanted to learn TIG... just need the machine to try it out !

The TIG would replace most any Brazing !

If it is like troweling then you are probably not doing it right. The basic idea is to get the temp right so the brazing alloy flows into the pores of the base material and produces the bond and then adding alloy to build up the layer. Good brazed joints are either lapped or a v grooved out to increase the bonding surface. A well made brazed joint will appear like a O/A welded bead. Same technique basically except you are not melting the base material. A well made joint with bronze alloy is almost as strong as the base material. Brazing is my go to process for joining dissimilar metals or unknown steel alloys.

I once did a bunch of SS castings to cupro-nickle piping for ship board salt water systems. Fit ups were too sloppy to make silver alloy filler efficient. Eventually went to an arc process copper alloy rod. Quicker, cheaper, and probably better. That is another brazing process that is very good for repair work. Nice working with cast iron/steel to other metals. Another story from the past.

Aluminum is somewhat different but there are alloys for that also. Melting temp differences between base and alloy are a lot closer so temp control is paramount to prevent melting the base material. At that point you are welding not brazing.

TIG brazing I have not tried as I am not a proficient TIG welder. I can see the advantage of more heat control with the smaller heated zone.

Ron

 

[3Lfarms]

Using silicon bronze filler with the TIG is actually easier since the base metal doesn’t melt. I am only an amateur, but my beads with silicon bronze look like the stack of dimes people like to see.
It is a bit more expensive though.

 

[Raspy]

Connecting a copper ground wire to rebar is a common grounding method called a Ufer Ground. All of the Ufer grounds I致e seen have used grounding clamps to connect the copper wire to the steel. Never seen one brazed on and don稚 see the need for it but then if I knew everything...

Good post.

A Ufer ground is the best grounding system there is for homes. it was developed by the military and found to accept the highest amperage at the lowest resistance.

The method is to bend up the end grounding rebar somewhere where it will be in the wall and near the service panel. Then an inspection cover is placed over it that can be removed to inspect. Best to have two long rebars coming to this location with the final foot or so bent 90 degrees up and exiting the concrete. Then an approved brass grounding clamp ties the two together with a conductor that goes to the service panel grounding bus. The grounding rebars are part of the reinforcing structure and are tie wired directly to the reinforcing grid in the foundation. All of which gets buried in concrete.

No brazing or soldering is needed or desired.

A variation on this is to have a number four copper conductor wrap around the rebar and clamp to it below grade. The copper exits the slab and runs to the service panel. This system is not as good, but often approved.

 

[Fallon]

I think I'd use a normal grounding clamp .... of the screw clamp type that is commonly used to connect copper ground wire to the grounding rods for household current. Home Depot...I think that would stand a better chance of surviving long enough to pass the high current in a lightning strike. Corrosion and conductivity reduction probably don't mean much to a bolt of lightning that has just jumped a mile through atmosphere.

However, if you prefer to use TIG it won't be a problem. Copper welds to steel fairly well. No solder needed. You may find that using an intermediate bronze or copper rod in your other hand will help the weld. Use the heat of TIG arc just as you would use an acetylene torch, NOT letting the flame or arc ever touch the area you are welding until the weld is done and it is time to add a little heat to the surface to smooth things up.

I've not done large silver solder (silver brazing) joints like you propose, but have silver soldered copper to steel. It's a natural easy joint. If I was dead set on using silver bearing solder like you are suggesting, then I'd clean and prep the joint, coat it with flux and wind the joint with some of the silver soldering wire. Then strike an arc an inch away from the joint and let the heat flow to the joint. That way you get clean heat to do the work. Oh, and have a piece of silver solder in your other hand to stir the joint as the metals begin to flow.

Naturally it makes sense to practice first.
good luck,
rScotty - ex K5EZK

A quick blast with the TIG torch & the copper welded to the rebar. It was almost disappointingly easy. I was trying to heat up the test chunk rebar to try soldering it on with some silver solder & accidentally got a good weld before I knew what was going on. Repeated it several times. Had some brazing flux on there, may need to up the argon and/or use a bigger cup. Copper got a hair thin on the first one & I broke it off just past the weld when I bent it a couple times.

 

[rScotty]

A quick blast with the TIG torch & the copper welded to the rebar. It was almost disappointingly easy. I was trying to heat up the test chunk rebar to try soldering it on with some silver solder & accidentally got a good weld before I knew what was going on. Repeated it several times. Had some brazing flux on there, may need to up the argon and/or use a bigger cup. Copper got a hair thin on the first one & I broke it off just past the weld when I bent it a couple times.
View attachment 623706

Congratulations on trying it. To make the joint less likely to break, it helps to stabilize it somehow. One way woud be to go ahead and use the standard grounding clamp to hold the ground wire to the rebar, and then weld the end of the copper that sticks out past the clamp. The most common type of grounding clamp would do that nicely.

Alternately or also, you could also flow some brazing rod around the whole welded joint - standard rod will flow nicely to coat and cling to both the copper and the steel ....as long as you don't get the steel too hot!! Dull red is plenty.

The best tool for putting on tht sort of heat that would be an acet/oxy torch set with a slightly soft flame about a quarter inch long. For TIG I'd use remote heat. The brazing rod can be either a standard low fuming brazing rod, or for even better results use a rod with 10% nickle in it such as All State #11. in either 3/32 or 1/8" size.
I like that rod for general brazing as well. It is stronger than low fuming bronze and a little more expensive, but not a whole lot more $$ than regular brazing bronze or silicon bronze.

Just to make things a little more confusing, the welding industry also often refers to this 10% bronze alloy as "nickle silver brazing rod" - probably because of the color. There is no silver in it at all, and it takes a standard borax brazing flux rather than the special flux used for real nickle silver.

BTW, if you are using brazing flux there isn't much need for more argon.
Good Luck, rScotty.
Here's some more photos.

 

[yomax4]

The Nickel Silver rods I use from Weldcote Metals are 10% Silver and the bare rod version uses standard Borax Flux.

 

[rScotty]

The Nickel Silver rods I use from Weldcote Metals are 10% Silver and the bare rod version uses standard Borax Flux.

Good info, there, yomax. In their metals cataglogue online, WeldCote lists both alloys: Nickel Silver and also Silver Brazing. The specs and % are in there too.
My experience is that not all rod companies will aways have the same alloys available.
rScotty

 

[yomax4]

Good info, there, yomax. In their metals cataglogue online, WeldCote lists both alloys: Nickel Silver and also Silver Brazing. The specs and % are in there too.
My experience is that not all rod companies will aways have the same alloys available.
rScotty

Yep, You are correct. it's all over the map. Some are givin fancy names for items that are nothing more than standard basic products.