For those looking to add to their welding knowledge base - and who aren't following my RacerBenz build on Grassroots Motorsports - here's a video I did today. I'm lifting it from my post on Grassroots, where welding of the roll cage started today.

One point here is that it's possible to use welding distortion to your advantage! Another point is that, holy jeebus, welding REALLY moves things! Plan carefully!
And I threw in a weld porn shot of one of the cage welds. Martin is something else...
Enjoy:

Ahead of welding, angles were checked on the main hoop and A-pillar legs. Why? You've all heard of the distortion welding causes so it's a good idea to plan your welding order. This allows you to better control what moves more easily and what doesn't. Turns out the left A-pillar was tipped in a bit more than planned (like 1/2 a degree) and the right side wasn't tipped in enough, by about the same amount. It's not something anyone would likely have ever noticed but why not do all that can be done to make things as close to perfect as possible? (BTW, yes, the bases of all the legs are tacked to the rocker boxes.)

So... we braced the right side A-pillar against the chassis and wedged the not-yet-final-length dash bar in between the A-pillars, "encouraging" the left side out at the top. That side, upper area was welded. Then we removed the dash bar and went after the top area of the right side pillar. With no bracing, when the weld cools, the welding distortion (shrinkage) "should" pull the pillar in, improving the angle.

Did it work? Take a look at this video and watch it happen as the weld cools! I started the video just after the welding stopped. Look real quick when the video first starts and you'll see the angle value starts at 89.4 degrees.

We checked again at the end of the day and it settled at 89.8 degrees. Nearly 1/2 a degree. The good news is it's now the same angle as the other side. The plan worked!


https://www.youtube.com/watch?v=bpy3HT-9hnw

my father was a boilermaker.
had all the tickets except the very top levels of super exotic high pressure pipe welding.

in the late 60s he was trained by a group of japanese welders brought to australia by BHP to the shipyards in whyalla. the training was in straightening and stress relieving steel plate after welding. they used flame torches and water quench nozzles. they were one piece hand held guns that came in from japan with the welders. he could still it do naturally as an old man. pull and relax a piece of steel straight after it had been continuous deep welded. plate or structural section. just with an oxy torch and a coke bottle full of water.

i asked him how he did it. he just said "black art".

he told the story. the japanese lined up all the workers. there were plates of distorted steel on the ground. the japanese proceeded to demonstrate in front of them. then called each man forward handed them the flame torch. let them go at it for a couple of minutes and either pushed them aside or directed them to stand in the selected group for training. they were looking for guys who had the feel.

at the end of it all he developed a taste for suntory. BHP shipped in cases of suntory for the japanese crew. none of them spoke english. the communication with the australians was through beer, grunts and smiles.

i've only seen one other guy do that same thing. years later.

This describes real craftwork. Not much of it going around these days

Good looking tig welds there! best advice is keep notches tight. no gaps

@Tygaboy - Wow, that was cool to watch. I love that weld-beautifully clean.

Thanks for posting

When I was learning to weld, we had big 50 gallon drums of 6"x8"x1/4" steel plates and we'd just make stupid stuff like 25lb bulletproof pencil holders. My first shot at making a box came out pretty wonky and the guy that was teaching me said you gotta set it up at a little less than 90 degrees and it will pull itself straight. He showed me by tacking one together a little off and then ran a seam and it was dead on. I asked him how do you know how much off to tack it. He just said, like this, and did it again. Arg. I went through a bunch of those steel cards and got a couple good square pencil holders and a great understanding of how critical experience can be.

Really good information. I just bought my first welder. I'm just waiting for it to arrive.

https://www.kickstarter.com/projects/yeswel...lder-and-cutter

Almost required for 914 owners, good call

Ive heard multiprocess welders aren’t good at either, this is really only a regular multiprocess welder with a plasma cutter. I bet the spaghetti of wires coming out of that thing will be a sight to see If your not a professional something like this makes sense, best of luck with the machine!

There are some videos on that page that show the various configurations. It looks simpler than you might expect. There are different wires fro the different processes but they are not all plugged in at the same time.
From what I have seen(youtube expertise at it's finest), multi-process welders don't typically deal with thicker materials as well as some dedicated welders but they can make good welds for the recommended material thicknesses.

Thats right.

there is a way to relax steel and relieve all the stresses and deal with its "memory",
its not only what you have done to it welding it, its everything thats been done to it before you got hold of it. built up stresses. mechanical straightening etc.

my biggest regret. i only ever watched my old man.
i never actually learned what he had.
i've got soft hands. and that skill he had has died with him.
its terrible. i'm guessing the same thing has happened in america.
which was the land of steel.
along with japan and germany. these countries knew steel.

there is that fantastic story about f piech checking out the emperor of japan's sword collection. he called one out as a fake. the CEO of VW was horrified and banned him from attending the tokyo motor show as a consequence. but the emperor was not offended and had his sword checked out. sure enough, it was a fake. piech could obviously stare into the grain of steel a bit like my old man. thats the guy behind the 914. knew his steel.