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There is an interest in the old school ways relating to autos and motorcycles. Partly because someone is building repairing something old. Sometimes, we just want to learn and practice old school because it's fun. In these cases, easier or faster has no relevance.
Too often, people will say " my friend did what you're doing, he built his own Mustang". I get defensive, because talking is one thing, prove it!. Many of us put a tremendous amount of effort into our projects and having someone " my way is better" after the work been done, can be annoying. Thank you for showing your work it proves you have real experience. Some people only have opinions. I believe our issue is resolved.
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Mike Last edited by Mike Motage; 11-30-2017 at 09:37 PM. |
#42
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Well done, Will!!
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Kent http://www.tinmantech.com "All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919. |
#43
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Jerry Jackson San Antonio |
#44
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With the shape sorted the amount of distortion is minimised and therefore so is the amount of planishing and wheeling afterwards so nothing should crack. I don't use native material as filler unless the material is something unusual or it's important not to have discontinuities in the finished job. Had to weld some 7068 recently and I wasn't about to put a line of something different through the middle of that so it was mostly fused together and topped up with some slivers of material I harvested from down an unseen edge. The only time I see cracking at the welds is when inserting patch repairs and welding old to new as it can be difficult to avoid inclusions or corrosion through older material. New metal with new filler shouldn't crack. At the edge of a panel I put a check weld in with the material cold then immediately hammer it flat to create a stretched area to prevent cracks growing inwards from the edge then weld up to it. If there is corrosion or inclusions causing cracking I'll sometimes use a hammer and dolly to stretch the weld into a nice hard crown to actually make it crack if it's thinking of doing so, I then weld it again then heat-shrink the crown down again to anneal and knead the metal into one homogenous mass. It's a bit of overkill but its extremely effective. Will
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Here to learn. William Pointer |
#45
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Jim and Jerry,
I tried having 1 long weld seam tacked using a newer inverter style Tig machine. I was having trouble keeping the 2 panels aligned and needed a second set of hands. He is better Tig aluminum than I and suggested the tacks would anneal. The tacks looked, were good, about 1/2" in length. I finished welded with O/A, everything looked ok until I started planishing the area. Cracks appeared at nearly every tacked point. I thought the tacks would get annealed by gas welding over them. Eventually I ended up with an acceptable joint but, the side that I did totally O/A is considerably nicer. Why? My skill is probably better at gas vs Tig. Did the tacks stay harder or more porous? I don't have the answer. I only know that on 52" long weld down the center of my bonnet between the power lump and scoops there was a problem. I know lots of people Tig their aluminum body panels, including a close friend and mentor. The ultra experienced coach builders on this site encouraged me to use O/A only and not mix the methods on aluminum. This has worked well, and I'm now confident in my ability to join aluminum panels. I have not tried every option, but have found what works me on the shapes and panels that I have.
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Mike Last edited by Mike Motage; 12-01-2017 at 10:15 AM. |
#46
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Sorry - I forgot about this question of yours .... I have seen and heard of these problems, cracking during planishing, with tig welding. If the filler is the correct alloy, the metal is clean prior to welding, and the inert gas is clean one would expect no problem. One thing remains: "Dilution." And, according to the Aluminum Association, TIG welding offers less dilution by its fundamental nature, than does OFW welding. With TIG you have to stir/agitate/mix the puddle as you weld, in order to facilitate dilution - something that OFW does naturally, by its nature. (Of course there are those welders who have no problems whatsoever with their work ... ) I have welded old aluminum to new repair panels on many different old sports/race/touring cars from several different countries, on several different alloys, with zero post-weld cracking problems - while I hear about so many problems with "old metal" - and its being blamed for the problems so much that whole original bodies have been scrapped for Mr. TIG to be able to weld nice Fresh Familiar Aluminum. (phooey on that ) It's not about "annealing" - it's about dilution. Dilution is the mixing of the filler into the surrounding material enough to make a healthy workable transition from one alloy to another. -end of lecture on that topic. ///////////////////////////////// Next Question: What is your (the) goal when welding your panels? To weld with as little filler as possible and just planish. Or do some file work before planishing. I assume our goal should be to use as little rod possible and planish with no filing to make the weld disappear. Mark When doing "panel work" - and not making tanks - the goal is to have a smooth surface across the welds lines. How you accomplish this is up to your skill level / your "style." I think it's fair to say that some craftsmen prefer finesse welding and finesse planishing to achieve their products - while others are content with being able to weld enough that the weld tops can be mowed off, the stalactites shaved from beneath, on the root side, and then go to smoothing by whatever hand tools or mechanical hammer or wheel to get to the goal. Both get the job done. Also: What is the customer willing to pay for? Is the job polished? Bare? Paint-grade? These are also worthy considerations. Some craftsmen are pushed into doing polished work while apprentices, and others may never see that type of work, so the style of work comes from the working environment, and not so much from the craftsman's preference - although some guys push their own envelopes just to find out what is over the horizon. hope this helps ...
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Kent http://www.tinmantech.com "All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919. Last edited by crystallographic; 12-01-2017 at 05:18 PM. |
#47
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Pretty sure Mike (and Kerry and Will and all the other people here building their own over-the-top personal car from scratch) passed the intersection of profit & loss at WOT long, long ago..... So now it's all about what they can and want to do. I like watching people chase excellence, just because they want to- Very cool stuff. Keep it coming, Mike.
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AC Button II http://CarolinaSculptureStudio.com https://www.youtube.com/channel/UCzSYaYdis55gE-vqifzjA6A Carolina Sculpture Studio Channel |
#48
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Only time I ever had issues with dilution is when diluting up, ie using a harder filler than the material I was welding. Sometimes on thin or poor material a 5xxx rod will flow better and seems to float off inclusions that bit better than the softer rods, which sometimes skin over the weld pool. But in that instance the problem is usually the state of the native material.
Never had to agitate the pool either. So long as the metal is flowing properly it will fuse together and just needs topping up with a little filler. Here's the other end of the pelican, by the way. Nowhere near finished but so far so good and a little of the process can be discerned. Head with Ruler.jpg Will
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Here to learn. William Pointer Last edited by Steve Hamilton; 12-01-2017 at 01:29 PM. |
#49
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Answers the questions or should I say blanks I had in my head - especially as very much a " learner " & hadn't heard of dilution - appreciate this is more of a problem if welding new to old materials - does this still also apply though if the same material is used as filler? - assuming new to new and filler is an offcut of the new. Not looking for a shortcut - as my personal goal with gas welding is as you say -just interested in the flexibility of the different processes and where they might crossover if at all.
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Jim "I have not Failed - I've just found 10,000 ways that have not worked" - Thomas Edison |
#50
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Where may people seem to go wrong in converting from gas to TIG is that TIG will put heat into the metal so much faster than gas so you can give it a bootful of pedal and get welding right away. This causes problems with the weld being quenched by the cooler metal around it resulting in brittle welds, all sorts of residual stresses and poor penetration. If the job is suitably heat-soaked before you start dilution should not be an issue at all even if you dilute up on new material. Will
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Here to learn. William Pointer |
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