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Customs I know it's not cold out but I have shrinkage....

Discussion in 'The Hokey Ass Message Board' started by Roothawg, Jun 15, 2019.

  1. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,561


    Well, not what you are thinking. I have been filling holes in the wife's 55. Ford had some massive holes for their trim. I have been putting washers behind the majority I can reach.

    The problem is that even though I let it cool and jump around trying to avoid warpage, I just spent the last 2 hours trying to undo my mess on the fender.

    I finally got it, but what is the proper recourse for when sheetmetal sort of sucks back in and basically causes a dent? How do you get it to pop back to it's original curvature? I ended up using a stud gun and moving the studs around to the lowest areas and working backwards. This is not the correct method, but I didn't know what to do. It's not oil canning, it just looks like a slight dent about 1/8" deep.

    I have the full length of the car to do, since I am adding the Pontiac Star Chief trim. It's makes a guy rethink doing a custom for sure.
    VANDENPLAS and chryslerfan55 like this.
  2. 49ratfink
    Joined: Feb 8, 2004
    Posts: 17,153

    from California

    fixing warps requires a magic hammer. only the hammer knows how to fix it. mine only works right some of the time.

    "I have been putting washers behind the majority I can reach."

    I like these. I think using them helps keep the heat down.

    yellow box came from Covell's but I don't think he sells them any more. the red box are thicker than old car steel, they are sweepings from a fab shop near me.
  3. G-son
    Joined: Dec 19, 2012
    Posts: 508

    from Sweden

    Hammer on dolly on the weld to stretch it out again?
    tb33anda3rd and chryslerfan55 like this.
  4. belair
    Joined: Jul 10, 2006
    Posts: 7,932


    Appreciate the lack of pics.
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  5. spanners
    Joined: Feb 24, 2009
    Posts: 725


    Back when we used to work on Noah's ark in panelbeating trades course, we were taught to hold a small piece of panel steel behind the hole and a blob of solder, When cool just file it flat. Bugger all heat so no distortion.
    Roothawg likes this.
  6. larry k
    Joined: Feb 23, 2009
    Posts: 273

    larry k

    You must remember that heat always shrinks metal ! It expands when heated , but shrinks 5 to 7 times what it expanded when cooled , So now it's smaller. You then hammer on dolly to spread it back to size . It's old time metal work that is not used much on newer cars any more . It is a very lost art !!!!!!!!
    49ratfink, belair and Roothawg like this.
    Joined: Dec 14, 2009
    Posts: 1,680


  8. rockable
    Joined: Dec 21, 2009
    Posts: 2,538


    Cut a disc of same thickness sheet metal and place it in the hole flush. If you cut them pretty tight, you can hammer them on dolly and get them to expand into the hold and hold themselves in place.

    Next, weld them in a little at a time and take time to let the heat dissipate. After cooling, hammer the weld down on dolly each time. By the time you are done welding them and stretching them out, you should be able to grid everything down smooth. A little more hammer on dolly might be required to stretch things out and finish the repair.

    As mentioned before, welding shrinks the metal ( and makes it thicker) and the only way to stretch it back out is to hammer on dolly and thin it back down.
    Pist-n-Broke likes this.
  9. 1946caddy
    Joined: Dec 18, 2013
    Posts: 1,385

    from washington

    Two problems with putting washers behind the hole. When in the sun, that area will heat and expand at a different rate than the surrounding metal and on the back side of the hole where the washer extends out past the hole, it leaves an area where moisture will creep into the space and rust out.
    You can use silicon bronze rod to try and keep the heat down and a copper backing or this sheetmetal repair kit.
    Hollywood-East likes this.
  10. Fortunateson
    Joined: Apr 30, 2012
    Posts: 2,105


    Not trying to hi-jack but there seems to be three thoughts on letting metal cool down... natural, wet rag, and compressed air. So what which should be used?
    Roothawg likes this.
  11. gimpyshotrods
    Joined: May 20, 2009
    Posts: 15,942


    Well, two of those can result in hardened metal.

    My former boss liked compressed air. Lots of cracks now.
  12. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,561


    I used copper as a backer when I could reach it. I am really trying to avoid pulling the fenders if possible. That’s why I can’t hammer dolly it in place. I may not have a choice.
  13. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,561


    You can’t tell anything when you are standing in front of it. Throw in crappy resolution or a 3” phone screen and basically you have nothing.

    Now, if you are talking about the lack of pics of my personal shrinkage, then you are welcome.

    That would not be something the masses would care to see. Although, the hamb is not impervious to hambers sending pics of their junk. Those who have been on here from the beginning know what I am talking about.
    Last edited: Jun 16, 2019
    lurker mick likes this.
  14. 49ratfink
    Joined: Feb 8, 2004
    Posts: 17,153

    from California

    what's that old Scottish saying?

    "Teach a man to fix a warp caused by heat and he'll be fixing warps for life, teach a man to weld without warps and he'll never fix a warp again."

    the Scottish are smart like that.
    OldSchoolRodz likes this.
  15. chopolds
    Joined: Oct 22, 2001
    Posts: 5,624

    from howell, nj
    1. Kustom Painters

    The ONLY way to fix warpage from welding is to stretch it, with hammer on dolly. You must work the seam only, not the surrounding area, that will create stretching where it doesn't belong, and make matters worse. Now, the problem with using washers, is that they probably aren't the same thickness as the sheet metal. you also have to fill in the center hole, making more heat. If the washers aren't the correct thickness, or if you put them behind the hole and they are a larger size, you really can't fix it the right way.
    Try it by cutting out small circles the correct thickness and diameter of the holes. As others have said, let cool and use hammer ON dolly technique to stretch the metal. Slowly, carefully, and watching how the metal moves. If you get the hang of this, and it is NOT very easy to get it, you can always drill out the 'washer fix' holes with a Unibit, and redo the holes the right way (even if the new holes are larger).
    rockable and Roothawg like this.
  16. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,561


    All good stuff here guys. Thanks. I'll have to rethink the way I go forward.
  17. Try to find a nail with a head the same diameter or near the same as the hole your trying to fill. Ya got a nice little handle to hold on. A couple tack welds to hold it, then weld the rest and cut the nail part off and grind flush. Worked well on 53 Mercury trim holes
    Roothawg and vtx1800 like this.
  18. alchemy
    Joined: Sep 27, 2002
    Posts: 13,707


    Root, were you welding the washers "behind" the fender? Not in the hole but behind? That is basically overlapping metals and you'll never get that perfectly flat. Do as the above guys have said and make or find some same-thickness plugs that will fit perfectly into the hole. Then butt weld them. No extra cooling, just natural air.

    As for the plugs, if you can only get some a bit bigger than the hole, it's ok to drill out the hole (use a unibit). The difference in metalwork required to do a half inch hole versus a three quarter inch hole is negligible.
    Roothawg and jimgoetz like this.
  19. Roothawg
    Joined: Mar 14, 2001
    Posts: 18,561


    Yeah, what I did was find a small fender type washer with a #10 hole and then welded them up on the bench. Then taped them to the back of the fender until I could get them tacked in.
  20. oj
    Joined: Jul 27, 2008
    Posts: 6,056


    Try using the discharge slug from a whitney punch. Choose the right size for the hole and punch out a bunch. Hammer them into the hole with the dimple facing out. When it shrinks from heat smack the dimple to stretch it back out.
  21. I know we all do things different so here's what I've been doing for about 30 years. On holes up to 3/8" and can get behind them even just by hand I Mig the hole shut. Metal must be clean on both sides as well as the inside of it. I use my hand tapered ream to clean them out. Now a Brass or Alum block hand held or clamped in place and do a Roset weld and fast as I can while Hot pick up my small grinder with a 4" 36 grit disc and grind the roset flat. With a heat block firmly in place you have no fall through to worry about. Once ground flat it might shrink just a touch but on dolly bumping will generally bring things right back where it started. 1/4" and smaller holes are a walk in the park. If you've never done it before practice on some scrap and you'll be surprised how well it works. Now if you have a helper that can handle the grinder it goes even better. Get them to handle the heat sink and grinder and you've got it made. I never use plugs under 3/8".

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