Old skills
While I was taking my apprenticeship, a thousand years ago, we were tested in a lot fo different individual skiills. One of them was flamecutting- most people think of an acetylene torch as a cruse tool, but a skilled operator can burn a 1/4″ nut off a bolt without damaging the bolt. I can still do that, and have done so as recently as a couple months ago. The tough part is freehand torchwork- the most many people can ever do is to get two pieces of metal to separate- but if you practice you can do some pretty amazing stuff.
Our step test, at the time, was to make a 12 x 14 angle iron frame. The tolerances were a little tricky, it had to be +0-1/8″. You had to have five centerpunches on each side of the cut, and the centerpunches had to be cut exactly in half, and the centerpunches had to match when you folded the corners. The gap at the corners when folded could be no more than 1/8″.
This doesn’t sound like it would be tough, but try it sometime.
I ran across my test piece a couple weeks ago, in the basement. I don’t know if I’ve got the freehand skills for that anymore, but I damned sure did then. I remember that of 35 or 36 of us, only twelve passed right out of the gate, and only two of us did it on our first try.
At the time we were also taking a math course and a metalurgy class. I remember doing sectional etchings so we could see electromicrographs of the hardness of the materials and how the differential temper caused stress internal to the material. Internal stresses in metals can cause catastrophic failure if the stress cannot be relieved. Prince Rupert’s Drops are pieces of glass in which the internal stresses cannot be relieved.
The glass has incredible impact resistance but if you snip it’s tail, as show in the video, the internal stresses are relieved. Similar things can occur in metals, especially small pieces of steel or other alloys that have been treated for hardness but not adequately tempered- the proper application of heat will draw the brittleness out of steel.
Anyway. I was in my early twenties when I took that apprenticeship. Now those skills are old enough to drive, drink, vote, and hold public office. They may not be as good as they once were, but they’re still there, the knowledge of metallurgy has if anything improved, and I wonder, where does all that knowledge go when I die?
19 comments Og | Uncategorized
Unfortunately Og, that personal knowledge is prob’ly the only thing yer gonna take with ya when ya leave this mortal coil
I use an oxy/acetylene fire wrench regularly. You can do some pretty amazing fine detail work if you know what you’re doing and have good tips. I keep my tips locked in a drawer in my toolbox. Much to the chagrin of the truck driver/shop hacks who struggle with the most basic cuts. Back in 77 I worked for a year in my Uncle’s welding shop and he commanded molten metal better than anyone I’ve ever seen. He ended up closing his shop and I’ve often thought that it was at least partially because he spent too much time teaching me instead of churning out work. He’s the one who made me buy my own tips and lock them up. Good advice.
I suppose if I wanted to learn that skill, I should start with something smaller, like soldering. I already did soldiering. I was pretty good at that. Then would come brazing. Though I would not throw myself into it brazenly.
I have used fire to cut steel, but there was no art to it, just making re-bar into shorter re-bar.
Did a lot of cutting with a torch; after a while you learn how to handle it like a scalpel. I miss that sort of work sometimes.
Art: This is why the guys like Carteach are incredibly important, to pass that set of skills off to the next generation.
yeah, it’s amazing what you can do with a torch, if you’re careful.
But Whoopi Goldberg has said that fire will not melt steel.
I think that was rosie odonnell, but yeah, you got the idea.
I like teaching my students how to cut one exhaust pipe off another at a joint, leaving one of them untouched. It’s a good skill to have, and ever so easy once you understand what you are doing. Still looks like magic though.
I recall working on a spray truck with a big block Ford gasoline engine. It had a few broken exhaust manifold bolts in the head. It was in a TIGHT place… far too tight to get even an angle head drill into. I was faced with pulling the head, and this fat and lazy man was NOT happy with that option.
I talked my employer into letting me apply a little metallurgy knowledge, and used a cutting torch. Getting the bolt glowing, I shut down the Cetti and blasted it with O2. The remains of the bolt came boiling out of the cast iron head like a scalded cat. All that remained was cleaning up the threads and installing new bolts.
Another favorite trick with corroded and frozen studs and bolts…. Heat the exposed part to cherry, and then shut down the torch and walk away. Come back after it cools and do it again. Repeat as long as you have patience. The repeated expansion and contraction breaks the corrosion bond and the frozen stud suddenly ain’t frozen no more.
“where does all that knowledge go when I die?”
Your apprentice?
Some of it, yeah. But damn, there’s so much.
And why do you think we will know all when we go to the great beyond? That all had to get there somehow.
Klein bottles are the same way. You scratch the interior of the thing and it’ll shatter. (I think it was Klein bottles.)
I actually considered this the other day thinking “how would I pass on what I know?”
If nobody died, we’d never get to show what we know, because all the old folks would be the “go-to” guys.
And we’d have less chance of a sense of discovery for the same reason.
Every position I have ever held from laborer to CEO I took as many as I could with me. Trained a lot of folks in a lot of fields in construction, engineering, construction management, finance, and how to show people a better way.
Now I use it on the range to bring young folks into the fold.
When I go (in the not distant future) I feel good that a lot was passed on.
Good post about ‘real’ qualifications, and the only thing you can do is to try to pass them along to your apprentices!
“Klein bottles are the same way.”
yes! I remember a teacher using one to drive a nail, and then dropping a paperclip inside it at which point it turned to powder.
Torch welding is an honest to god art form as well. I have managed to do it a few times, swirling the little puddles of melted metal into a beautiful weld. The other fifteen hundred times I tried it, it looked like someone puked molten steel over and across a gap in the material.
You truly need an artists touch to do it right, and my fine motor skills (which were never all that to begin with) are going to shit at an alarming rate.
I try and pass along the “black art” of making machines do the things they don’t teach you in a manual as often as I can. It’s always gratifying when the guys from the company that made the equipment tell you something can’t be done and you prove them wrong :)
Well, that glass video explains the results of dropping Pyrex on a hard surface. Very few things shatter like Pyrex.
Or an old toilet.