Brazing or torch welding

When I attended a vocational H.S. in Buffalo that's all we had was oxy/gas welding and brazing, they had a stick welding class but that was only for the night school classes, but they did teach us how to tin radiators with 5 lb. coffee cans and the old steel soldering irons..As far as brazing bigger stuff with higher pressures, I split one of the bolt together glands on the lift cylinder on a '57 ford tractor, friend of mine worked at a welding shop said they could fix it..They heated up a manhole cover with a rosebud and brazed the cast gland on top of that smokin hot cover, then they threw a fire blanket over it heating it several times for a slow cool process..that was 20 years ago and its still working...

My first vehical the exhaust manifold cracked. Every one wanted $100.00 to fix it i found a guy for alot less.I got what i payed for so i cut it apart and mayed a jig and bought some cast torch rods. I learned 2 things how to weld cast and the cheap guy isnt always ceaper.

From age 12 on I welded auto body panels in with oxy acetylene. 52 years later it is still my preferred method. It introduces a lot of heat to the sheet metal, so it needs hammer & dolly work to bring it back to shape. I couldn't do $hit with coat hangers. An old garage owner suggested hay wire, but all I could find was rusty. I used 1/16, or .045 I can't remember what it was called RG45? It was a mild steel with copper coating. These days I grab ER 70S2 TIG rod whether using TIG or flame.

my 2 cents. i only use brass brazing when the metals cannot be fusion welded by any reasonable means. i have had to repair stuff where the previous attempt involved gobs of brass all over and then a repeat failure. trying to remove brass down to virgin metal is hard because it permeates the porous nature of the casting-that is what creates the bond--just like soldering. also, brass does not work well for exhaust manifolds. sometimes, an exhaust manifold is so rotten from continual red-hot heat cycles that it is not worth welding unless another one is unobtainable. for some jobs, pre-heating and ni-rod 55(or similar) using smaw(arc) welding is my preferred method and depending on the part, a long prolonged cool-down(maybe even a day or two). oxy/acetylene with bare cast rod and flux can be good but is more time consuming for cast iron repairs, but again, it depends on the job at hand. no one solution fits all. for sheetmetal, i like to use mig with an S-2 wire--it is softer than S-6 wire but depending on the application it will not have the same tensile strength. i also previously used coat hangers for filler rod, but in the last 35 years, the coat hangers are not predictable in composition due to being made from recycled metal. some are brittle and questionable composition and plastic coated, etc. i just buy the proper filler rods in various diameters and then i know that they are correct for the application. on sheetmetal, more heat inputs cause more distortion which has to be dealt with but may have more consistent full penetration than MIG. the bottom line is, use the best method that is readily available as long as safety is not compromised by the welded repair part and is legal

skyking1 said:

TIGs were a rare thing but we had one. I also remember somebody casting a Hurst T-handle shifter handle, having a little sag in it.
He then heated it up with the TIG till it practically went away! Aluminum be funny like that. Solid, still solid, oopsie!

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We had a hot metals class. They would not let us cast the hurst t handles out off brass for obvious reasons.

What was the deal with everyone casting Hurst handles in 1985? lol. Same thing at my high school. Or, 1911s. Hard to believe we could bring guns to school, (with prior approval).

I don’t recall what I made for my casting project.

Yeah, brazing isn’t the best choice for hot things.

I still do a little brazing and mild steel welding because I am intimidated with tig.
I quit using coat hangers when I could finally afford real welding rods.
A helpful tip for anyone that has never welded mild steel with a torch and wants to try it, would be to have a rich burning flame. It prevents that horrible popping and banging that will some times blow the molten pool of metal out.

Coaldust said:

What was the deal with everyone casting Hurst handles in 1985? lol. Same thing at my high school. Or, 1911s. Hard to believe we could bring guns to school, (with prior approval).

I don’t recall what I made for my casting project.

Yeah, brazing isn’t the best choice for hot things.

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1985? LOL newb.

Never brazed or tiged, crap at souldering and have not gas welded anything for 15 to 20 years even though i really liked it .
I mig my hydraulic fittings together if they are clean enough or stick weld them if not. Often have concerns of debris left inside but usually only do it when needs must. Alot of the time you do what you have to keep the show on the road. Waiting for a new part is not always the best option.

One place i worked had a trailer hub that was brazed i cant remember how but when i pulled it apart i couldnt belive it. To top it off a very pour job. The guy that ran the other shop re brazed it and it never caused a problem. I think the hub was broken some how between the front and back races.It was a 50 ton trailer.

skyking1 said:

1985? LOL newb.

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I too am older than casting Hurst shifters.
I hit "Industrial Arts Class in 1969. I'm told they had an incredible IA teacher who killed himself in 1968. The room was divided. North was metal machines, there were enough equipment to rebuild an engine. These were covered in sheets as though they had died.

The South end was filled with high end (donated) Powermatic wood tools. These were as delivered when they were delivered. The planer was as dull as my thumb, The bandsaw didn't have teeth. The lathe was very high end. I sneaked tools home & sharpened them at night.

This was a college prep school! If you wanted to learn anything other than stock trading, you were a failure. No encouragement would be given to any variety of mechanic.

One day I noticed a vibration crack developing in one front fender of my Jeep. I reasoned, this is shop class, this the first welding in years, I'll fix it. Seconds later "Mr. Wood Rasp" appeared. "Mr. Beauregard, it is obvious you already know how to weld. I suggest you make a candle holder."

I likely remember it a bit off the exact quote, but I'm not off in the message. He had made a failed try as a carpenter. His wealthy/influential/board member father in law thought he was a perfect IA teacher, and indeed he was. To this day, candle holders adorn cellars and attics that were built under his tutelage. A candle holder includes two short boards, three nails, and a Chinese bought cup.

Like Bill Cosby's ashtray story. No matter what you started with in shop class, it ended up with two notches and became an ashtray.

skyking1 said:

Like Bill Cosby's ashtray story. No matter what you started with in shop class, it ended up with two notches and became an ashtray.

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I sir, have never made an ash tray! Just my phobia, If my mother had smoked fewer than six packs a day, my family history would be different. I'll credit her with one thing; three children they, had three spouses, among us 6 grandchildren & their spouses, not a smoker in the family, not even weed!

After reading some of your posts, I feel absolutely blessed about my high school. We had an entire wing devoted to the trades: building trades (still active), fully equipped wood shop (some years active, some years not), fully equipped auto shop, and a complete metal shop with stick/mig/tig welders, forge, aluminum foundry, and all the tooling required to run everything in the shop. Don't get me wrong, the school board has tried to kill those programs on an annual basis by budget reduction, but they still live on and thrive. Currently, all programs are active, though in reduced capacity. When I was in high school, 20 years ago, the metal shop class always had 20 students for every hour of the day. I learned a lot of unique skills in my 4 years of metal shop and I am very thankful I had that opportunity available to me. As a freshman, we had 5 required intro projects: center punch on a lathe, vee block using mill and surface grinder, cold chisel using forge, foundry project of teachers approval, and a sheet metal toolbox. After that was intro to stick welding using a Lincoln buzz box. I still have my 5 projects that I made my freshman year. After my freshman year, my shop teacher let me work on whatever I wanted, as long as I stayed productive. One of my favorite projects was casting an aluminum riser block for my 440 snowmobile handlebars. After casting, I used a mill for finish machining and cleaned it up nice. I always got asked questions about where that custom riser block came from.

colson04 said:

After reading some of your posts, I feel absolutely blessed about my high school. We had an entire wing devoted to the trades: building trades (still active), fully equipped wood shop (some years active, some years not), fully equipped auto shop, and a complete metal shop with stick/mig/tig welders, forge, aluminum foundry, and all the tooling required to run everything in the shop. Don't get me wrong, the school board has tried to kill those programs on an annual basis by budget reduction, but they still live on and thrive. Currently, all programs are active, though in reduced capacity. When I was in high school, 20 years ago, the metal shop class always had 20 students for every hour of the day. I learned a lot of unique skills in my 4 years of metal shop and I am very thankful I had that opportunity available to me. As a freshman, we had 5 required intro projects: center punch on a lathe, vee block using mill and surface grinder, cold chisel using forge, foundry project of teachers approval, and a sheet metal toolbox. After that was intro to stick welding using a Lincoln buzz box. I still have my 5 projects that I made my freshman year. After my freshman year, my shop teacher let me work on whatever I wanted, as long as I stayed productive. One of my favorite projects was casting an aluminum riser block for my 440 snowmobile handlebars. After casting, I used a mill for finish machining and cleaned it up nice. I always got asked questions about where that custom riser block came from.

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Back to the subject at hand: I had an exhaust manifold on my snowmobile blow a hole through the thin stamped steel. I brought it into the shop and brazed the hole shut. I put it on the sled and rode a couple weekends with it while I waited for a new manifold arrived from Arctic Cat. It held up, but my shop teacher warned me it would only be temporary. I made a lot of replacement snowmobile parts in metal shop class over the years.

My dad has a TO 35 that some one broke the corner off the manifold were the pipe gos on some one cast welded one side and brazed the other. I re brazed the one side once then got anothert manifold.

I had accident with my Dodge timing chain cover this week today i fixed it. my torch came with a small deal of flux and some very small rods. I had never gas welded aluminum before so i tryed on junk part one tack i was ready. After it was ground down it looked better and most important it seemed to hold. Welding cast aluminun isnt easy. The rods were so small they would burn up when they saw the flame i will get some bigger rods to practice with.

If welding aluminum use the puddle to melt the filler. That is, dip filler in the puddle, don't actually hit the filler with the flame.

The small rods i have used you have to withdraw the flame to get it to the puddle.

Old Doug said:

The small rods i have used you have to withdraw the flame to get it to the puddle.

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Exactly