steel welding

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devino246

devino246

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To help illustrate the point, here are some cross-sections.

Brazed joints:



Note how there is an obvious divide between work material and filler metal.



Welded joints:



Note how there is no defined line between work pieces and filler metal.
 

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souperman000

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devino246 said:
Not really. Welding (modern, anyway) requires melting both work pieces in order to join them together, with or without the use of filler. Brazing, on the other hand, involves heating both work pieces to sub-melting temperatures. A filler metal with a lower melting point than the work pieces is then melted into the joint where it joins the work pieces together. The only difference between soldering and brazing is the temperature at which the process is performed. IIRC, anything under 1,800*F is considered soldering; above 1,800*F is brazing.
Click to expand...

I went to a gun show on Saturday and a guy there was trying to sell these aluminum rods to me. He said they wold work on anything. Just heat both with a propane torch and they melt together.

Is that just brazing? I didn't think it would work for welding something like a kart frame. He did have a propeller that was fixed with that method though.
 
Doc Sprocket

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souperman000 said:
I went to a gun show on Saturday and a guy there was trying to sell these aluminum rods to me. He said they wold work on anything. Just heat both with a propane torch and they melt together.

Is that just brazing? I didn't think it would work for welding something like a kart frame. He did have a propeller that was fixed with that method though.
Click to expand...

Once again- Is the base metal being melted, or just the filler? If it's just the filler, it ain't a "weld", it's just brazing.
 
OzFab

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Ok, wrapping all that up:
1. If you're referring to a MAPP torch, no you can't weld with it as it's not hot enough. The best you can hope for is brazing.

2. By the time you buy an O/A torch kit, you could buy a cheap arc or flux core welder.

3. Unlike arc or MIG welding, O/A is not easy to master &, if not done correctly, can cause a lot more damage than electric welding (arc, mig)

I'm with toystory, either buy a welder or pay someone to do it for you
 
machinist@large

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Keep it comin', guy's!!! You're doin' great!!

New job is keeping me jumping, and wearing me out!!:furious2::roflol:

The outfit I'm now working for is a heavy industrial repair company, and I'm the new guy in the machine shop. WOW!!! It's been over 20 years since I worked with equipment this big: I've rented machine time on machines at the smaller end of what my new emp. has, but those were just cruel flashbacks to better times.

Where I'm going with this is some of the parts I've been working on; I've got several different examples of a couple of the processes this thread is carrying on about. My flip phone doesn't take the greatest pic's (plus I have to tear it down to get to the memory card). Let me sift thru what I've got; I'll post anything that you can actually see what it is.:surrender:

Devino; you're doing great with the info and pic's you've been posting (wish I knew how to do all that). Some of the pic's I'm hoping :)worried2:) turn out will hopefully amplify/ further explain different processes. Give me a little bit; I'll see what I have and post accordingly.:thumbsup:
 
machinist@large

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Hmm.... let's see if this works....

Let's see if I can make this work again....:ack2:

OK. If the preview is what actually goes thru, then disregard photo's #1& #3 for a moment. Photo #2 does show the example of BRAZE WELDING (A.K.A. brazing) that I wanted to upload; but it's from the wrong angle, and way to much clutter. (The one I wanted is trapped in the photo editor; I managed to get it in, haven't managed to get it out.:oops:) You're looking at the wrist pin end of the knuckle joint for a 1,200 ton cap. stamping press. In this pic, I'm reboring the thrust face area. Where this comes into the discussion is the metals; gray is the original cast iron, yellow, is where it has been braze welded back together.

Braze welding, while strong, doesn't come near the strength of the parent metal (in this case, high carbon grey iron). In this application, as it's on the non working load side, the repairs (to both ears) are more that sufficient to carry the load of the knuckle (approx. 4 tons), the press ram assembly ( 3~4 tons) and the weight of the top half of whatever stamping die the customer loads in it (small press; maybe 4~6 tons max.)

In this shot, I've already re-bored the wrist pin holes in line and to a common size; I'm reboring the thrust face in line with the pin holes.

Photo's #1  are from me playing with my phone while machining the head frame for a foam saw; #1 was from my position on the 6 Foot step ladder looking up at the controls. Photo #3 is a pull back showing the machine while it faces off one of the mounting pads. The actual machine is moving left to right at just under 8 inches a minute in both shots; work piece is tide down on the stationary table. The ladder is riding along on the operator's platform, which is bolted to the base of the traveling column.

Photo's #1 and #3 are included because I'm still trying to learn more about how to use the bumbling box of binary bit's that so many of you just can't seem to live without......:ack2::bannana::oops:
 

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