Who else still hammer welds?

I have to get half hammered before I tig or gas weld, calms the shaky left hand from the brazing fumes over the young and dumb years.

 

That's "Hammered welding". I think that might have been what the last guy was doing on the butchered bird!

 

[HAMMER WELDING]-- Has nothing to do with TIG -MIG -OR-FUSION GAS or anything else. IT IS A GAS WELD ONLY -and you '' hammer" the hot weld.


" Real hot rods don't have fenders"

 

Wtf

 

I'm confused,i thought the principal of hammer welding was to avoid shrinking and streching?

 

I'm sure you aren't and maybe the process you use produces a different result but when you weld with a gas torch, the metal (almost) always humps up and needs shrunk. A good example is when you weld shut a bullet hole, you end up with a big dome if you don't shrink it back down.

 

Much of the time you can't avoid it, it's a method of dealing with it.

 

I disagree. Described this way, it's simply a task required for an inferior process.

 

Thanks Highlander,it all makes sense now,i have 3ft long patch-panels to weld into my coupe doors,i should have em done by xmas,and a few grey hairs as well!

 

Highlander, I think we are talking about 2 different processes. What I concurred with was that hammer welding (as I know it) is a gas torch process. I have welded enough to know that an arc weld shrinks as it cools but hammer welding is a different process in my mind than hammering an arc weld. When I started the thread I was curious how many guys still used the old hammer welding process, like was done long before mig or tig welding became widely used.

 

Oldcarguy, it doesn't really take long to do. If that's all you have to work with, it works just fine. You only tap the weld a few times, you don't wait and go back. It's easier, and frankly faster, than it sounds. It does take a helper to do it well, and do it quickly. 3ft seems like a long way to go, but control your warpage and keep it flat, done in no time. Depending on the shape and different tensions in the door I'd start from the center and work outward, swapping sides as required or observed. if you tig or O/A, you don't need this.


Willow, I get it. My dear departed Dad always did O/A, hammer welding. Still have his torches, but I prefer the other methods. Maybe i was adding this stuff because of those who want to, maybe can't or ever tried, have an alternative that will work.

 

Apparently the rules physics and thermodynamics are different in your shop. The only shrinking I do when hammer welding with gas is if and when I over stretch the weld.

It's really pretty simple. When the metal is heated (by any method) It expands and softens. As the expanding sheet metal pushes out word it's trapped by cooler harder metal. So you get a high or low spot AND the pressure causes increased thickness in, and around the weld area. When the metal cools it contracts, looses the "bulge" but retains the slight increase in thickness. The result is less surface area. Shrinking! You counter this effect by STRETCHING the weld with hammer on dolly.

When heat shrinking you simply help the natural process along by hammering on the heated area to force more thickening and reduce surface area. Keeping the dolly loose, rather than striking directly against it as in stretching.

But hey, if what your doing works, good for you! Call it whatever you want.

 

i use a torch and hammer weld 90% of the work i've done on my car.
sometimes use a mig to tack stuff in place.
i'm no master but i learn.

 

The hot smokin tip is to fit your metal so you don't need any R-45 filler rod in there or at least minimal. Daubing the filler rod just keeps the heat on there longer. When you weld without filler, the weld puddle sags a bit and the hot area shrinks. The hammer & dolly is for stretching the shrink back out as necessary and leveling the sag of the weld seam.

 

Your late night trips to the "parts store" might lead you to a trip to the hospital or the morgue if I caught you.

 

I didn't intend for this to turn into a battle or a whose smartest thread. I was just wanting to see if the process I was taught by an old blacksmith 45 years ago was still used by any members. rotorwrench is correct, if the fit is good enough you don't even need filler rod, more of a melt strip as we called it in high school welding class. But I'm not that good at fitting sometimes so I have to use some soft wire filler rod. I've learned a lot of stuff over the years and probably am not that good at any of it, but that doesn't keep me from appreciating an artist at work or from learning new stuff. Gas welding is an art and can easily be out done with more modern methods in most instances. My point in asking wasn't so much to discuss alternative methods or argue linguistics as it was to see who amongst us does it like I was taught.

 

David does low pressures with a conventional torch. Need to add, fusion, no rod. Dont want to confuse the issue.

 

No argument or offence intended. But as a teacher I know the importance of understanding the physics of what your doing. I take every opportunity to encourage people to put down the MIG and pick up the torch.I was a heavy collision tech for years before I started teaching it. My skill level increased dramatically as I learned more about what I thought I knew! That happens when you learn to teach!
I still use rod, I'm pretty good, but am very interested in learning more and better ways. That's why I'm here. I never gas welded till I found this place in 2001. So please, I'm sorry if I offended you, lets continue to discuss this.

 

Metalurgy is a big part of metal joining technology that seft taught welders don't learn. A trade school will teach a good portion of that if it's worth it's salt but the average home shop welder has to put heat to metal to see what happens to it. The other part is what happens when you apply hammer force to metal to stretch or straighten. Two different techs put together in one. To be a good metal man you need to be relatively affluent in the skills of both technologies.

I learned on oxy/acetylene because that was still common in repair of aircraft steel tube frame structures at the time I went to tech school. A guy would be nearly crazy to try and repair a chrome moly tube aircraft structure with O/A gas welding now. TIG is a much better way to go. But for sheet steel in the lower carbon range, O/A is still my prefered method. The old welding & body smoothing methodology might be slow by todays standards but the paint & finish work later is much easier and therefore faster. I hate sanding frickin Bondo.

 

Oh, and thanks guys, I just spent two hours this morning hand fitting floor patches in
this fucking t bird ! I'll probably park the MIG and gas weld the damn things in now

 

Hey guys,with the mig if i'm butt welding a patch panel,is the gap the same thickness of the material i'm using and also with tig is the hammer welding tech the same as the mig ,thanks, Gaz !

 

BINGO!!!! and don't rapid cool it.

 

Some like it the same, I like it a bit smaller for less filler and quicker fusion/hammering. If your fits are good you need only stretch the weld. As mentioned above, metallurgy is indeed involved. A couple cups of coffee and google will teach you a few basics that may or may not help, but DON'T overthink it. Mig tends to be brittle. It's the biggest downfall to that method, which is why I mentioned EZ Grind or other alloys. In real simple terms they're "softer" to begin with, but will still get brittle some as you stretch. Perhaps with O/A and near perfect temps and control, the joint itself anneals throughout the process due to the time it remains hot. Again, a google search will get you a simple knowledge of annealing. This is why I like TIG. Near perfect fits, temp control, speedy process when you get it down. As a disclaimer, big American iron from the mid 30s is pretty easy to tig together. A 34 Packard fender thickness is more like a unibody subframe thickness on cars today

 

i prefer the tig process........better fitment

 

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Hammer welding originated from the factories on damaged parts. The assembly line sheet metal was much thicker in the '20's and '30's. Most body panels were 16 gauge.

There should be no argument. The best repair on old metal is the exact method done by the factory.WHY USE GAS? "LESS HEAT" AND ALSO MANY OTHER WIRE ARE TOO BRITTLE. Today's steel is completely different. The name is "HIGH STRENGTH" and a different molecule makeup. WIRE FEED - TIG OR GAS. Good results by an experienced welder. I have seen tons of bad and unsafe wire feed welds with little or no PENETRATION.

" Real hot rods don't have fenders, UNLESS THEY'RE GAS WELDED ON. "

 

Howdy! Let me add to the dialogue. I bring 60 years of experience to this discussion. Not to imply I know everything. I do not claim to. Traditional hammering welding is basically OA. Weld seam, an inch or so and hammer weld while hot, or weld whole seam, then reheat bead and hammer weld while hot. Object was to flatten weld and maintain and adjust shape as we went. Works best with two guys-torch guy and a hammer guy. Works equally well alone , just slower.
Distortion is caused by the weld shrinking as it cools. It will be there, always in varying amounts. It is a waste of time to obcess about trying to eliminate and minimize warpage!!! It is going to happen. It does not matter if it is warped an 1/8 inch or a foot! It all comes out the same way. Lets' talk tig. Tig is more efficient and faster. works best alone. Tack sufficiently to hold edges even and weld it up. No need to jump around and stop to cool, etc. I normally tack entire seam and hammer tacks to ensure alignment of edges and overall shape and then weld it solid from start to finish. Grind tops off the welds from top and bottom. Stay off the parent metal. Hammer stretch HAZ only until distortion is gone. Bingo!! Hammer weld is problematic in that you are stretching hot metal that is trying to cool and shrink naturally at the same time. you can become very skilled but probably not perfect and this requires more additional work to properly finish. End results are or can be equal in quality and then it becomes a matter of personal preference. One other point I like to flow edges together when tacking, no filler rod. You can finalize edges without grinding spots tig or OA. But I always add a small amount of filler rod when welding solid because it is easier to finish the seams without pits, etc. Hammer welds especially, are easier to finish without filler rod but the seams track much more. So add rod. The finish seam should show up as a line, different color, no pits. I still ocasionally hammer weld but I think tig is much faster with equal quality.
Lastly, I promise!! You should always have proper fitment, proper shape and takeoff, before starting the welds. Sorry for the long winded babble. It is often been said don't ask tinguy what time lit is because he will end up telling you how to build a watch. See ya!! hope it helps some. tinguy, Paul Bragg

 

second time in this thread I say WTF.

are you serious? that's the most outlandish statement here yet.



the "most were 16 gauge" comment is bad enough, but 10 to 12 gauge? on what? an armored halftrack from WW2?