i want to learn to weld...

[DJW]

DValintine, yes for sure, weather can cause much havoc on the job, the first job I started on in steel fabricating work when I came to the USA was in western NJ. I was told there, even shells rolled and seams welded in the shop during the day at night the seams would split with a bang owing to the cold at nights. Bulling a job is so costly and makes far more work than the job deserves. In Britain we never had weather as the USA gets, have no idea how cold it gets there but the ground only freezes down 1/2 inch, (but Bloody miserable though) so I had very little knowledge of weather conditions in the US. Often there is very little preparation given even before the job even starts. After NJ I headed for California, and Loved every minute of it. There is much to take into consideration when temperatures get so low. Wind is a problem with welds, on one job I was troubled with porosity with LH and it was summer, oven heated rod, the welds were not critical but I was concerned, I asked the engineer, he said they had the same problem in Arabia on oil tank storage welds, said regardless of per-post heat arc coverage etc. wind was the deciding factor. I also remember being told, heat produced moisture, or moisture was a product of heat. (can't win either way) They are great pictures, those Heads are a pretty picture a Real Work of Art. On some jobs it's a Bug-Bear how much time you have on the Crane, that's if you are working composite, (or some other weird title) I got along with all, in fact I got more work and overtime with the Ironworkers than from my Millwrights on the job even as a Millwright working composite. Also asked for my address and phone number at end of job, saying, "I'll call you first before calling the Hall, so you know I asked for you". I Enjoyed Work, Problems only enhances the Doubtful Pleasures, the Pay Check after all is just a Bribe, to Encourage to attend the Gathering.

 

[DValentine]

DJW, I would like to know more about the Sub Arc you made for welding the ductwork, mentioned a few pages back. How did you build it? This machine we used on the coker on the horizontal welds they (CBI) used on tanks. We had others that ran on the flat, inside the shell of the can sections. Will explain more later.



Greg, the cans were made from putting 4 quarters of the shell material together. Small enough width to truck to the site. The quarters were laid in saddles to make up halves. The cladding was explosion welded to the shell, then rolled in a shop. The clad was back an inch off the bevel. We welded that up last with Inconel. So we laid two quarters in the saddles, fitted the joints with key plates and strong backs to lock the seams. We could work two halves at once, with four saddles. I don't have a picture of the sub arc we used here to weld the joint... from the inside of the can. The machine ran on three wheels down the joint of the two quarter sheets laid in the saddles. The joints had a 1/4 in land on them. The joint was slammed tight, and the key plates, strongbacks kept the the parts from moving as they were heated. We used long propane burners to heat to 400 degrees. The heat, as you know makes metal do funny things. Before I got on the job, the first two quarters they laid in the saddles and applied heat, warped. They thought they had ruined them. They cooled off and came back to shape.



So the steel was welded with the sub, then the clad with the sub to make a half. This was moved and two more were welded. The two halves were put together, fitted and spun so the edges fit were now on the are on top and bottom. The Sub Arc welded the bottom joint. Now on the horizontal plane were the first two joints. We back gouged and hand welded the outside, again this was preheated by long propane burners. We turned the can sections with a large crane and spreader bar. We had some bad pictures which took a lot of time to fix, slowing production. Thus the girth welding sub arc. We found out later that some of the bad pictures came from the lap weld onto the cladding, done with the sub arc. The clad had a little hook on the edge that trapped slag as the weld was made. We later buffed the edge of the clad and got rid of the problem.



DJW, the picture of the girth sub arc, the seam had been back gouged and then welded with the sub. The machine was moving to the left side of the pic.

 

[DJW]

DValentine, the machine was of a quite simple design. Imagine two pieces of heavy plate formed into two long Ss, about 20 feet long, these faced each other, (left and right hand) thus forming a trough with the bottom edges about two inches apart. Of course this was all contained in a frame substructure. Directly below the opening of the formed trough was a heavy pipe, I also believed it contained a strong back to resist bending. Said pipe was hinged at the closed end and the front, (open loading end) was secured by a hook, over locked. The pipe surface below the trough opening was covered with a length of brass? copper? with a shallow wide grove, this was to place a bead on the inside of the pipe from the top, this would be further stiffened with a row of hydraulic cylinders, so when the pipe was in place the whole unit would be ridged. The welding head was mounted on a toothed beam running the length of machine. One started on the open end which had a starting coupon about 2X2 inch. I forget the exact procedure but machine turned on, check dials, lift crank handle to bring wire in contact and engage toothed rack, the same time flux deposited and away to go. One kept eye on speed and amp and voltage dials. As the machine progressed just behind the deposited weld a vacuum lifted the loose granular flux. The machine was all self contained, just had to make sure all systems were working. At end of weld press stop button and raise carriage. The solidified flux could be salvaged ground up and reused, however with the leaking hydraulic oil contaminating solidified flux we discarded it. (hard enough getting results required without additional problems, it was new to that plant). They said the man who designed the pipe seam welder designed a gasoline storage tank production line, producing 3 tanks per hour. The shell was sub arc welded, the heads placed one each end at the same time, welding heads at top of seam (I believe a few degrees below top so as to solidify weld), and each head welded together, 20 minutes the whole welding operation. If one can control all conditions one can do wonders.

 

[DJW]

DValentine I worked at United States Steel for a short time, I was in the structural department, but if caught up went to the pressure vessel side. I once noticed flat plates being joined using sub arc, I went and spoke to the operator, the head was carried on a regular oxy-acy tractor (carriage?) a pointer was mounted just ahead to keep the seam in close relationship to the wire. Not sure, because it was free run so to speak, no confining barriers, he had a helper probably another operator to assist, he told me that on general lay offs he was kept on, and he thought it was because of his use of the sub arc. If one can pay attention and solve problems a company is reluctant to lay off at whim. (a pretty face dosn't always cut it). I believe the plant was Chicago Bridge. That was about 1960

 

[GHarman]

Dave and DJW

Man, you gents are really providing Excellent input to this thread. The Pictures are Great. Keep it Coming. GregH

 

[DValentine]

Greg tell me how you got your cap, on the practice pieces you posted, so smooth. Were you running free hand, or walking the cup? Boilermakers don't tend to walk the cup. I need to learn it.

 

[GHarman]

Walking the cup

Dave, The only free hand I do is on aluminum, small diameter tube and odd shaped pieces. GregH

 

[DJW]

DValintine, 'cap and walking the cup', don't even sound English to me. Is 'cap' a cover pass? 'walking the cup'? can't even take a guess at that. In 1955 at the plant I worked in NJ, Jet rod was only used as a cover pass say over 3 or 4 passes of#5, #5 for out of position and tacks, #7 for flat and fillets. (all mild steel of course). One strange test I took for the AEC, fact took 3 different tests at same sitting. (overtime job) The AEC was a fillet, one plate flat, another at 90 degrees, fillet joining both. First pass flat against vertical but have to melt edge of vertical but weld bead had to measure 1/2 inch wide used Jet. Second pass a different rod, (you were given two rods and told how to use them, one for flat and melt edge, the second to finish fillet to measure 1/2 inch) Lay first pass down, clean weld lay next about 45 degrees to finish with a 1/2 inch fillet. (got one try at it) Each test for a particular design, rod and size used to their choice. (after all they know what they are doing don't they?) At different times I've used Jet on Re-Bar, one place I worked said when I questioned it's use said it was a 70 rod so OK to use. One of the inspectors also questioned it's use, I told him what my employer said, so after welding the bar to a plate asked if he could test it I said sure, he took a piece of pipe slipped it over and bent it flat, he said OK use it. (Do some make the rules as they go along?)

 

[DJW]

GregH, once I had finished welding anchors (bent pieces) on 12 lengths of aluminum angles used to cradle plates or gratings in concrete floors, (mild steel don't last long exposed to chemicals used in food preparation plants) (pepto-bismal anyone?) the anchors were placed about 12 inches apart. They were ready to be shipped and the owner took a hammer and tapped each one, he asked me why he done it, then said the last lot that had been done, on arrival at the job site the inspector tapped each one and they all fell off. They had been welded by another weldor.

I told him each time I was going to weld on a different material, I'd set up the machine see how the rod or wire ran when satisfied, get a bucket of cold clean water, a large hammer or sledge, tongs or pliers and have access to a heavy vise. Run a bead of about an inch or circle if to a bolt etc. take it and plunge into bucket of water, no waiting around for it to lose temperature, cool till hand hold, place in vise and try hammer to try to separate the two pieces. One needs to know if it breaks wether in the weld, penetration, or if material. At least try and learn something out of it. For my own shop if changing wire for a higher grade, testing new machine, gases etc I always made two samples, one to try and destroy, and place the other on a shelf if needed for future reference.

 

[rbattelle]

I always made two samples, one to try and destroy, and place the other on a shelf if needed for future reference.

That's very clever. Did that extra piece ever come in handy?



Ryan

 

[DValentine]

Cap, being the cover, and walking the cup..... um have you ever moved a 55 gallon drum by hand? You walk it back and forth. Do the same with the cup of the TIG torch.

 

[DJW]

rbattelle, no I never needed it, being I had my own business I wanted to make sure to myself whatever I was producing at the time, was never in doubt. At some plants when welding tests are required for what ever reasons two test plates were done at the same time, one for the one who called for them to be tested, and one incase there was any question regarding quality of the test, sort of witness plates. (never trust anyone) Even when employed if change in procedure or switching to stainless or aluminum, or any change I'd do my own test. When I sat down to take a test I was fairly sure I would pass, otherwise I wouldn't waste my time, theirs and material. I am primarily a lay-out and fitter and only weld if the job required it or if employed as a straight weldor because of high overtime or if it suited me, in fact welding bores me stiff, although I believe a weldor should be the highest paid in the trades. It takes physical dexterity and human skills many will never reach, regardless of how hard they try, and how well they are trained, hand and eye coordination just for a start, and often under very difficult and trying conditions. Any clown can read a print, I can break a job down for a cutting list and get the darn thing right first time like winky, I've had to correct many prints even before starting the job. Welding mistakes can be very costly but most of all dangerous.

 

[DJW]

DValintine, now I understand, I thought the cap may be a cover pass, of the cup my thoughts went to completely other matters, starting with a C and D size, cupped my right n hand and took a guess at the size, more accurate I found than a tape or calipers, speaking from experience of course. (Liar) I done very little tig great for fine work, I used to weld a washer on the end of 1 1/4 steel pipe and thought a tig would be better than the mig even using . 030 wire. The tig would have taken longer, later my son showed me one he had done, I asked tig he said no, I asked . 027 no again, he used . 035 it was hard to believe as it looked a perfect tig, he said he just got the machine right, it was a Lincoln a new model, computer stuff, 5 languages etc. I bought it being it was the latest, but for myself failed to need to take full advantage of the machine. About the only tig I done was to weld stainless hinges on stainless steel covers, no filler used just fusion weld. (stainless steel as stronger than Iron as they used to say) I did some on aluminum pipe but failed to make it look like a row of coins, takes good coordination to achieve that. (can I borrow the grinder? can I grind it?)

 

[GHarman]

DJW,:-laf Funny PostGregH

 

[GHarman]

DJW, You remind me of a Gentleman that was in charge of the Welding Program at a local Technical School 22 years ago. I worked with him in his last year as an instructor. He would be in his mid 80's now. I havent talked to him in years. He was a very knowledgable weldor/fabricator that had been a foreman for many years in a local Iron Works company. Man, could he tell the stories. One of his great comments was "I wouldn't hire you as a Tacker", in reference to some kid that had just ran a bead after using drugs in the parking lot at lunch break. I learned alot from him and received permission to copy his personal library of weld procedures that he accumulated over the years. He was a hard nosed German from Wisconsin. In his shop it was "head down, butt up and sparks flyin' ". Those kids knew that they walked into the real world when they took the welding class:-laf. GregH

 

[GHarman]

Press Brake

DJW, Do you remember the formula to calculate bend allowances on plate and sheet stock for 90* bends with given radii? Do you know what the minimum radius for a given thickness/type of material? Did you find the orientation of the rolling grain a consideration when making minimum radius, 90* bends (we ran into end splits on bends that were parallel to the rolling grain, Carbon Steel))? Some of this information I have in my archives, packed away. Was wondering if you have used this and if you would share itOo. ?



BTW, rolling grain on plate tests should be perpendicular to the weld. Coupons crack along the rolling grain adjacent to and into the toe of a weld when the rolling grain is parallel to the weld, when bending a test coupon. Thanks, GregH

 

[DJW]

GregH, no I have no chart regarding radius, I dimly remember given a formula which was quite simple, as it needed no or very little math. and could be readily calculated without pencil and paper. I do have around somewhere, a sliding scale for punching holes in steel regarding tonnage, and did have one for specification of wire ropes, another for hydraulics. Scales are very convenient and easy to use, they were often given away if one worked in the trade, or if asking by the steel supplier, etc. About all I have now is a materials wall chart Structural and the same in a book given by steel supplier. A good book can be had from a steel pipe supplier, from manufacturing, to welding procedure of joints, avoiding cold laps etc, very through. After all it's to advance the trade thus the supplier also benefits.

Some years ago there was concern (Panic?) for Laminations, that is when a member is welded to a steel wide flange, the member beveled to flange finishing with a fillet. In time the member can part from the upright flange because lamination the w. f. column being fiberous. On welding those kinds of connections, I always thought in addition to the joining member being beveled the column should also be grooved, as you are only welding to the skin so to speak, and not creating a good bond. I have always felt that on structural erections no connecting bolts should be in Shear, bolt to facilitate erection, but not structural strength. In machinery I have seen much damage caused by a bolt failing, if the bolt fails over time, there should be a fail safe design engineered into the product.

When plate is sheared, if minimum radius bends are formed they should be across the grain, that is not parallel with the rolled edge. If a plate has four sheared edges I do not know how to find the grain.

I went into Construction Millwrighting in 1975 so most of the material was already formed, and unless working temporary in a shop, then information would be given or would be on the drawing.

 

[DJW]

DValintine, I never heard or seen it in the trade, but years ago looking through one of my son in high school textbooks, I saw and read of the procedure of claimed the largest pressure head ever formed, it was formed using explosives in the San Francisco bay, a beautiful job, claimed it only took about 100 lbs of explosives. Must have taken very extensive calculations to come up with that. There was only a note regarding it, much like a passing item, rather than a to me, very detailed account. I have heard of explosive engineering , but could refer to quarrying, earth removal, demolition etc. Years ago heavy castings being made ready for scrap were broken using explosives, I worked with a Blacksmith who was quite familiar with it. Years ago explosives were very commonly used almost as a household item, fact I worked with a man that lost his father and mother when someone walked into the powder room smoking, it was being used on the farm.

 

[DValentine]

DJW I just looked up explosion welding on Wikipedia. Interesting article.

You lost me on your discussion on the previous post about steel flanges and such. Would you revisit, and explain what you are talking about. I haven't hung much Iron.

D

 

[DJW]

DValintine, this was all pipe fitting in a fertilizer plant where sulphuric acid was produced, the steel flanges I mentioned were welded to chrome molly sch. 80 pipe, the pipe looked just as common steel pipe with rust, as I was told, depending on the amount of chrome in alloy, however they couldn't be cut with an oxy-acy torch, just an uncontrolable drip, we used air-arc to cut then taper them for welding, the weldor I had working with me, could finish them as if they had been machined, just like from factory, (he was also going to weld the joints) The only time we flanged the pipe was when the line was connected to a pump etc,or a riser from a tank or container, being the flange was steel, (you can get them in Stainless but very expensive, plus only had to be protected where it came into contact with acid) we had to clad the bore with stainless welding rod as were all the pipe joints, and I believe part of the face, not sure now but I believe a 150# flange has a raised portion to connect to pipe and a protruding machined plane face for gasket surface. The sch. 80 flanges which we only used on steam lines were the 3,000# weld neck, but we used the 150# on acid lines as the pressure was not high. (and a lot cheaper) Where the 150# flange could be in contact with the sulphuric acid we'd clad with stainless rod, it wouldn't need any further preparation as it was all internal. Often on many jobs one can use cheaper materials and only use as they used to say,"Expensive Steel". where required.