Brazing question

[cnyeco1]

I bought a little Oxy-Ecetyl combo the other day and would like to learn how to braze small stuff. Like making homemade tools or artwork. My question is, I was watching some videos on you-tube for general info and the guy was talking about coated bronze rod and un-coated. Also the paste method which looks messy to use.

So which should I start with? Is one easier or safer than another? The welds looked the same but he was a pro.

Thanks in advance.

 

[Ed T]

I've had good success with both approaches. Starting out, you may find the coated rod easier since there's one less thing you have to remember. I still use uncoated rod as well as coated rod. One advantage of the uncoated stuff is that you can use the rod for other things like paint bucket hooks and things like that. The coated rod is not so good for alternate usages.

 

[rtremaine]

I like the coated rod because it's less mess IMHO. Plain rod and paste works well also. Main thing is make sure what you are brazing is super clean and that the metal flows toward the heat. It one of those 10 minutes of instruction, 10 years of practice type of skills.

 

[tcianci]

One thing to remember... you may or may not have seen guys wearing goggles while brazing. In order to braze you need to get the steel cherry red. At this temperature the metal is giving off light in the IR range, not good for the eyes. Wear goggles designed for brazing.

 

[APEowner]

Coated rod doesn't store for long periods of time really well. A can of flux on the other hand keeps darn near forever if the top is on tight. Other than that there's really not much difference.

 

[cnyeco1]

One thing to remember... you may or may not have seen guys wearing goggles while brazing. In order to braze you need to get the steel cherry red. At this temperature the metal is giving off light in the IR range, not good for the eyes. Wear goggles designed for brazing.

I bought a pair of Hobart welding goggles with #5 lenses in them. Hope that's what you mean. Yeah, all the vids. I watched said to be sure to wear goggles. I'm a nurse so I damn sure can't live without my eye site.

Thanks guys.

 

[JC23]

It looks like you've got the jist of it on here. One more thing is that if you get the stuff too hot, it will pop sending burning hot stuff everywhere. OUCH! You don't want that.

Don't forget to throw some pics up of the stuff you've made. We dig pics.

 

[trythis]

Shade 5 for oxy-fuel unless you are using a massive tip or cutting titanium.

Warm up the brass rod, dip in in borax, yes, the cleaner, same basic stuff as the welding supply store.

Brass is copper and zinc. The zinc burns and produces fumes that are quite poisonous. Make sure you have good ventilation, the copper fumes aren't healthy either. Bronze rod has no zinc, it is copper and tin, or in most cases silicon, but really, bronze is any copper alloy that has no zinc. No welding fumes are healthy.

I pulled this from the Department of Labors site:
ZINC

Zinc is used in large quantities in the manufacture of brass, galvanized metals, and various other alloys. Inhalation of zinc oxide fumes can occur when welding or cutting on zinc-coated metals. Exposure to these fumes is known to cause metal fume fever. Symptoms of metal fume fever are very similar to those of common influenza. They include fever (rarely exceeding 102o F), chills, nausea, dryness of the throat, cough, fatigue, and general weakness and aching of the head and body. The victim may sweat profusely for a few hours, after which the body temperature begins to return to normal. The symptoms of metal fume fever have rarely, if ever, lasted beyond 24 hours. The subject can then appear to be more susceptible to the onset of this condition on Mondays or on weekdays following a holiday than they are on other days.

 

[scooterseats]

I have found that the use of powdered flux is better because you can control the amount of flux used where the coated generally has an excess of flux. Generally once you have the surfaces tinned, you do not need much additional flux to continue the joint. This is true, especially if you are using the brass to fill or build up the work piece.
As one post said, avoid overheating, just to a "Cherry Red" color is sufficient to make a great joint.

 

[Professur]

And you will be truly sick at how effective brazing is compared to welding.

 

[cnyeco1]

Thank you guys again for the tips and knowledge. If you think of anything else keep it coming. I freely admit I know NOTHING about gas torch set-ups.

I went and got a owners manual for Victor torches and am reading it cover to cover before messing with this thing. I have also been asking bunches of questions.

The funny thing is that I was a production mig welder for years before going to nursing school and we always had gas torch stuff around, but I never took the time to learn how to use them. I guess at the time the stuff the can do with them didn't seem cool.

Bummer.

 

[orion]

I don't understand; brazing is effectively gluing pieces together whereas welding is making 1 part from 2 or more. Fusion welding is much stronger.

The benefit of brazing is the lower temperature. You only need to heat the parts but you don't need them to sweat/melt.

 

[Professur]

Brazing is much less prone to cracking and inclusions, and works well to fill pinhole rusting. It's softer than steel, so smoothing it to the surface is easier than grinding down the weld, and there's less heat involved, so warping what you're working on is less of an issue.

 

[trainer]

Brazing used to be the standard for auto bodywork before mig became widely available.

It works great for joining thin sheetmetal to thicker structural pieces.
It works good for repairing cast iron.

A good practice is to rough up the surfaces to be brazed with a very coarse grinder. this provides a "tooth" for the bronze material to bond onto .

 

[lilredex]

Brazing is much less prone to cracking and inclusions, and works well to fill pinhole rusting. It's softer than steel, so smoothing it to the surface is easier than grinding down the weld, and there's less heat involved, so warping what you're working on is less of an issue.

Warping is still an item of concern, it is easy to get careless, especially out in the middle of a panel and end up with a huge mess. This work was all done with a "000" size tip and a flame just larger than on a birthday cake candle. Just large enough to have the brass flow smoothly. Work was extremely clean and it turned out perfectly with a minimum of fill.

 

[sdowney717]

on that Borax.
Can you use boric acid roach powder?
Can you use mule team borax?
I notice that the flux coated rods loose their flux and it would be nice to use some thing i already have for flux.

 

[EVOLVO]

Back when I used to braze bicycle frames I used an All-State Jet Fluxer along with brush on flux and uncoated bronze rod. A jet fluxer is a small cylinder that is filled with liquid flux, the acetylene out of the regulator is connected to the jet flux tank, there is a tube in the tank that goes almost to the bottom, the acetylene then bubbles up through the flux molecularly bonding and carrying flux out to the flame front. Used like this in conjunction with the brush on flux virtually eliminates any oxidation of the metal. Soaking the cool finished braze in water melts the flux away. After a bit of practice I didn't even file my fillets.
Hope this helps!