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welding potmetal??

Discussion in 'The Hokey Ass Message Board' started by Ether, Feb 27, 2008.

  1. Ive got a buddy (what a bad way to start a thread!!!) who is considering chopping a 54 lincoln capri convertible. He has asked if I had ever welded potmetal as some of the top mechanisms are. I have messed with it a while back with mixed results. Anyone had better results with this and how/what did you use to get it done? Ive got a Synchrowave 250 and a good bit of hands on, but need a little help on this one before we jump in. Or how to tell potmetal from aluminum ETHER
     
  2. Should be able to find a solder that will work
    on Potmetal,which is mostly Zinc,IIRC.
     
  3. "Solder Fast Zinc" is a Zinc Paste Solder.Supposed to be good for Zinc bearing alloys.
    Melts and flows at 400F.

    1/2oz syringe should be under $10.


    Test it on something else first.
     
  4. Jessie J.
    Joined: Oct 28, 2004
    Posts: 354

    Jessie J.
    Member

    There is a product called "Muggy weld" that works miracles on pot metal and aluminum.
    http://muggyweld.com/
     

  5. Do you know if this stuff will hold up to the stresses of a top. Have ya used it with good results.
     
  6. mazdaslam
    Joined: Sep 9, 2004
    Posts: 2,524

    mazdaslam
    Member

    I would lower the mounting points for the top frame.
    Sink it down into the body.
     
  7. lostn51
    Joined: Jan 24, 2008
    Posts: 1,667

    lostn51
    Member

    years ago when you welded grease duct or any galvanized metal after you cleaned it of real good you got a torch and warmed the area up and you took this rod and rubbed over it like solder. it was a Zinc rod and thats what i used to weld up the top mechanisms on my dads 50 Ford convertible. they work really well but i dont think they make them anymore. i pilfered these from a real old shop here in town when the company i used to work for bought it. check with a steel company or supplier they might have some or know where you can get some at. but you have to Heli arc them together with these rods.
     
  8. BOBBY FORD
    Joined: Oct 6, 2007
    Posts: 700

    BOBBY FORD
    Member

    Ether, I welded my 54 chevy tail light housings onto my 53 chevy with a mig welder. used .25 wire and 75-25 argon. Tried core wire on wire welder and it would blow holes in the sheetmetal and would not stick to the pot metal. My guy welded with angle toward pot metal side and it stuck good and didn't blow any holes. Don't know about top bows as they would have more pressure. If that doesn't work for you, you might try small flat brackets on each side of bow in area cut and countersink holes and use small nuts and bolts. Thanks, BOBBY FORD
     
  9. They call it Muggy Weld,but any filler that melts at a lower temperature than the metal(s) you are joining is considered
    Soldering.
     
  10. zbuickman
    Joined: Dec 9, 2007
    Posts: 466

    zbuickman
    Member

    Soldering, Welding, Glueing, who cares what its called does it hold and how strong is it. I too am WATCHING this thread as I have a part that was broken while in storage. and is irreplaceable. and of the 2 Ive seen for sale in my lifetime the cheapest was 3 times what I paid for my car:mad: So far this is the only rerpair Ive seen that is replateable. so how strong is it should I trust it to hold on the outside of my car??? Does any body have experiance with this product????


    as for the original post my convertable top also had some potmetal parts on it. They have now been refabbed from steel. this worked out very well for me.:)
     
  11. When tig welding, what setting did you use (ac, dc-, dc+) and did you use an argon or helium mix? ETHER
     
  12. lostn51
    Joined: Jan 24, 2008
    Posts: 1,667

    lostn51
    Member

    My dad welded some dc. and i welded some ac. the only thing i like about ac high frequency is that it cleans as you weld. thats why your aluminum or brass has the funky discoloration next to the weld. but dc strait polarity is what i would use to weld them if i was you. the pieces that i put back together has been on the car for 15 years or so and we have never had a problem out of them at all.
     
  13. Jessie J.
    Joined: Oct 28, 2004
    Posts: 354

    Jessie J.
    Member

    Call it what ever you like, it works extremely well and is very "user friendly"

    The trick here is in the flux being used that also acts as heat indicator, allowing the base metal to be heated to the correct temperature before the introducing of the filler rod, which with its low melting point is quickly drawn into the base metal by capillary action.
    Some call it "welding", some call it "soldering" and some call it "brazing", but the bottom line will always be whether it accomplishes joining the metal in an acceptable fashion.


    Actual gas aluminum "welding" can be accomplished however, but it is a skill that not very many are willing to master, particularly now that so much easier and "user friendly" methods are readily available.

    If you've ever held a torch to a piece of aluminum angle for example, you will note that if you are careful, you can usually raise the temperature to a dull red, just before the heated area disappears into a plop of molten aluminum on the floor.
    Anyway, within that very narrow range of temperature the metal will be semi liquid, and essentially only still holding to its original outside shape by the "surface tension" of the invisible corrosion layer that always forms immediately on aluminum when exposed to oxygen,
    proper rod and flux introduced at this point will produce a truly "welded" seam , with the the filler rod actually mixing and alloying with the parent metal.
    This why aluminum can be actually "welded" together into one seamless integral piece by either electric or gas "welding" processes.
    Prime examples of this are the old Ferrari and Cobra aluminum bodies that were of fully gas welded construction, without need of "lapped" or "soldered" seams.

    Most "pot-metals" will have a too low, or unpredictable melting points for much chance of success with actual gas "welding".
    This is where such low melting point "welding" rods as "muggy weld" and equivalent products really show their worth.
    With the caveat however, that some really old (think 'teens and '20s) "pot metal" was of such a low, or indeterminable composition or quality, that any repairs will prove risky, if not impossible.
     
  14. duke182
    Joined: Nov 27, 2005
    Posts: 562

    duke182
    Member

    you can buy rods that work with low heat(hand held butane torches)at harbor freight. bought some at grease-a-rama for crazy mopney then found them for cheap at harbor freight.
    WORD OF WARNING: REGARDLESS OF THE METHOD OR MATERIAL YOU USE PRACTICE,PRACTICE ,PRACTICE ON SCRAP PIECES FIRST.
    you don't want to melt hard to find parts.
     
  15. duke182
    Joined: Nov 27, 2005
    Posts: 562

    duke182
    Member

    bought some at grease-a-rama for crazy mopney

    for those of you that don't read my new language mopney translates into money.
     
  16. rodknocker
    Joined: Jan 31, 2006
    Posts: 2,267

    rodknocker

    I'm with Mazdaslam on this one.Sinking the frame work of the top would be the safest way to go.
     
  17. CharlieLed
    Joined: Feb 21, 2003
    Posts: 2,460

    CharlieLed
    Member

    I have used Muggyweld to repair broken 50 Merc grille center sections and various other small parts with great success. The "weld" material appears to be harder than the original pot metal when doing the finish grinding. So if the bond is good, then the repaired part should be just as strong as the original. I've seen demos where they have actually drilled and tapped it for bolts...I haven't used it for that yet.
     
  18. T McG
    Joined: Feb 12, 2005
    Posts: 1,261

    T McG
    Member
    from Phoenix

    Muggy has two different rods, a high temp and a low temp. I have never had any success with it. I have tig welded pot metal using dc and aluminum filler rod. It works, but with the stress that will be on this part, I doubt it would hold up. Alladin makes some all purpose rod for this type of material that does work well. It is called 3 in 1 rod, and is available at most welding shops. I too would look at sinking the top down.
     
  19. Garyr
    Joined: Sep 20, 2006
    Posts: 75

    Garyr
    Member

    remember anything the contains zinc is poisonous when vaporized. don't breathe the fumes, it'll kill you.
     
  20. duke182
    Joined: Nov 27, 2005
    Posts: 562

    duke182
    Member

    if you do inhale the fumes be sure and drink a big glass of milk. for some reason the milk will counter the effects of zinc poisoning.
    no bullshit it really works for minor exposure.
     
  21. I got a good look at what im getting into and well it seems the pieces in question may be aluminum. Im wondering how to tell potmetal from aluminum. The rails that go from the hung mech. to the A-pillers is what we are going to weld.
     
  22. marktp1967
    Joined: Sep 3, 2006
    Posts: 37

    marktp1967
    Member
    from arizona

    hey ether,
    i've repaired potmetal trim with alladin 3-in-1 rod. first you must gingerly remove the plating with a grinder. be careful not to dig in. you will see a thin layer of copper that the plater uses before the final plating. you want to grind that away as well. i would recommend using an oxy/acetylene torch set up with a soft neutral flame. try running at 4 p.s.i. each side. try to keep your flame really long. when you light up and bring in the oxygen, leave the flame big and billowy. when you practice you will notice that you can't really heat the affected area or you'll wind up with a big splat on your workbench. dance the flame on the work and the rod, when it's right it'll go right together. good luck and don't use too much heat, keep pulling your flame in and out. i have had good success using these methods and materials. mark
    p.s. if you can somehow fixture your work (i.e. clamp to a table or inside an "L" angle) you will increase your chances of a good result.
     

  23. If the part is what you call 'potmetal' it cannot be fusion welded.

    If it is die cast zinc alloy it can easily be welded with TIG and the correct rod.....and I think the part likely is...auto makers did not use pot metal for structural parts....only non-structural like radio knobs and trim pieces....eutectic and MG alloys have such rods for TIG welding zinc alloy....

    HOW TO TELL IF POT METAL??????

    STRIKE AN ARC ON AN EDGE WITH TIG TORCH.....IF THE METAL ACTUALLY MELTS AND FLOWS EXACTLY LIKE MOLTEN ALUMINUM UNDER
    TIG ARC IT IS ZINC ALLOY.....IF IT ONLY BUBBLES UP AND FUMES OFF, THEN IT IS 'POTMETAL'......

    USE A/C HIGH FREQUENCY BY THE WAY......

    THAT IS ONLY METHOD TO QUICKLY TELL......

    IF it is 'potmetal' there are low melting point flux free brazing alloys available and they will produce a very structurally sound bond.....

    private email me after you tig test if you wish and if in fact it is 'potmetal"
    and I HIGHLY DOUBT IT IS, I will get you the specs on the potmetal brazing rods I keep in my shop...it is real good stuff but dont remember the make right now.
     
  24. gotta add one more tech. thing......

    all die cast zinc alloy parts have a 'oxide skin' on the outer surface that will not melt!!!

    use must first cut the skin away with a grinder.....otherwise only the zinc underneath will melt and you will mess things up...

    PS: DIE CAST ZINC ALLOYS DO NOT FUME OFF WHEN TIG WELDING....THEY SIMPLY MELT SIMILAR TO WELDING ALUMINUM.......

    AND DRINKING MILK WILL ALLEVIATE 'ZINC CHILLS' THAT CAN BE GOTTEN WHILE WELDING GALVANIZED STEEL.....
     
  25. rustyford40
    Joined: Nov 20, 2007
    Posts: 2,168

    rustyford40
    Member
    from Mass Bay

    Potmetal will not stand up to stress. its junk metal.
     

  26. unlikely parts are aluminum....likely zamac which is zinc zlloy die cast.

    easiest way to tell cast zinc alloy from aluminum alloy is simply by the weight....zinc alloys are heavy, alus are light....
     
  27. I guess I may need to post a thred to ask if anyone knows what the rail is made of rather than asking how to weld potmetal. Find out what it is and then figure out how to weld it!!! thanks for all the input guys. ETHER
     
  28. Tinbasher
    Joined: Feb 13, 2007
    Posts: 274

    Tinbasher
    Member

    Lot's of input on theis one. Get a hold of a Plating shop in your area and see what there using to repair Pot metal. These guys deal with it everyday. If there's no luck there and stength seems to be the factor here. Can you make the part out of Steel?
    An idea anyway. "The Tinbasher"
     

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