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Sheet Metal Question

Discussion in 'The Hokey Ass Message Board' started by brassspike, Mar 18, 2013.

  1. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    I'm repairing the bottoms of my doors. Naturally, no repo skins so I have to make them. The problem that I have is that, when I cut the metal out of the skin, I have a bow inward in the center of the door. I could run a re-enforcement behind the skin but is there a better way to keep this curve out?
     
  2. MP&C
    Joined: Jan 11, 2008
    Posts: 2,477

    MP&C
    Member

    Is your inward bow referring to what is left of the upper door skin after the bottom is cut out?
     
  3. tinmann
    Joined: Nov 11, 2005
    Posts: 1,588

    tinmann
    Member

    The inward bow is caused by the stresses put on the door skin way back when it was stamped. When you have your replacement panel fabricated and ready for installation it has to have a little crown rolled/wheeled into it. As you install it, it will lose some of this crown. The actual welding in of this panel is some of the trickiest welding there is. I would not even try to run a weld bead. I do it all with well-penetrated tack welds, hammering on each one while still red hot, with a flat-faced body hammer on the outside and a firmly held dolly from the inside. If you install a stiffener like you suggested, you will not have access to hammer and the skin surface will take off in any direction that it chooses. Please post pics of your progress and all the armchair experts (myself included) can talk you through the process.
     
  4. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    Yes, its the left over sheet metal.
    I have had the replacement panel rolled to match the curve of the door but I don't have a way to wheel a crown in. Maybe there is a way to do this without an english wheel?
    Some areas of the door where the repair seam will be will be difficult to get a dolly on also. I have flanged the seam for overlapping so I am hoping this will help with the heat from the spot welds? I plan to punch the overlap in several places for some of the welds.
    Thanks for any advice. I'm trying to go slow and learn without hosing this up too bad
     

  5. jamesdfo
    Joined: Mar 16, 2006
    Posts: 133

    jamesdfo
    Member

    What method did you use to trim off the lower portion of the skin? If you used snips, you may have stretched the edge.....

    here is a good thread from metalmeet on welding all the way across doorskins....controversial, yes:)

    http://www.metalmeet.com/forum/showthread.php?t=6292
     
  6. fordcragar
    Joined: Dec 28, 2005
    Posts: 3,198

    fordcragar
    Member
    from Yakima WA.

    Some pictures would help. You don't want to put a flange on either the part, butt weld this. It sounds like you had the patch panel made to duplicate the curvature in the door, but didn't put a crown in it, is this right?
     
  7. tinmann
    Joined: Nov 11, 2005
    Posts: 1,588

    tinmann
    Member

    I'm not a fan of flanged panel installation. They give a false sense of security from warpage..... and make it damned near impossible to correct the warpage when it starts.
     
  8. rawcjw19
    Joined: Oct 8, 2012
    Posts: 581

    rawcjw19
    Member

    Hoping for some good info ,I have a couple doors to skin also.
     
  9. pimpin paint
    Joined: May 31, 2005
    Posts: 4,937

    pimpin paint
    Member
    from so cal

    Hey,

    You can induce some crown into this patch panel by clamping a dolly with the shape of your door skin in a vise, and gently pulling the panel across the dolly whyle forcing down on it. Go very slowly with this method, and check your work. I'd cut a couple of templets from thin cardboard, from the undamaged shotgun? door, and use it for a standard for your repair.

    I ain't big on step/joggle seams in door skins as they make hammerwelding/shaping problematic, but you'll probably be able to make this work. Once you've welded up the skin,you'll need to stretch some of the areas of the patch where welded, and this will remove the waves, and restore the crown of the skin.

    " Do not reach greedily for the Kool-Aid ''
     
  10. Another fact that will aid you is this.....
    When the repair panel is adequately shaped to suit you and you are installing it,remember this.
    Align it where it will go and clamp it in place on the corners.
    on your butt weld seams-do not cut it exactly where it touches the old portion of your door,at the joining seams.
    Allow a gap there at these joints.
    A gap about the same as a thin cut off wheel [roughly .050 is ideal]. this gapping will allow for less heaving or warping when welding and will allow easy"matching" of the two edges as you install it.[this can be done from inside the door at time of welding.....
    If the fit is really tight and touching at the joints you will experience a lot more trouble with warpage in your seams.....
    those little bolt clamps a lot of guys use are really not even necessary and will only hamper the ability to adjust the seams edges as welding them.....
     
  11. ems customer service
    Joined: Nov 15, 2006
    Posts: 2,634

    ems customer service
    Member

    if it is 55 ford like in your profile door bottom kits are in the works

    ems automotive


    the ems guy
     
  12. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    Thanks. I have it steped already but I do have enought metal in the skin to cut the step back out if needed. I would rather not if I don't have to.
    If I could get the crown back into the existing metal, I'd be in good shape. The door is on the car in my av. and there is no crown in the skin as it was from the factory. I'm checking the bow by using the side of a level along the door, front to back (no crown). If I can work the door close enough to use a skim of filler, I'll be good to go for this project. The previous repair by someone was pretty thick and I cut all of that out.
    If someone can hold my had through this repair I'll try to post pictures etc along the way so that others can benefit too.
    I've done some metal work but really need to be told the basics here so that I don't mess up real bad. I know the first try won't be perfect but I've got to start somewhere!
     
  13. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    Hi EMS. I got what metal working experience that I have by working some floor panels that I got from Macs. I HOPE they were not yours! Man those things were crude. I've heard good things about ems parts and I'm going to look your way when I get these doors done. I've got more work to do on other areas. I wish you had rear quarters in one piece!
    Are you doing the entire door skin from the window down? When will it be ready?
     
  14. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    Will pulling a dolly under the existing bow have a crown effect on it as well?
     
  15. pimpin paint
    Joined: May 31, 2005
    Posts: 4,937

    pimpin paint
    Member
    from so cal

    hey,

    I'd suggest you ditch the step/joggle flange, and go with a butt weld. This type of weld (butt), will allow you to work the welded area. Some of the distortion now in that panel was probably old damage! I'd grind off all the paint and any filler on the door, prior to doing any straighting/welding.
     
  16. ems customer service
    Joined: Nov 15, 2006
    Posts: 2,634

    ems customer service
    Member

    macs sell ours and the other guys

    ems always puts a label with our name on it!!!!!!!!!

    does not have our ems label then it is not ours
     
  17. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    It wasn't yours! It broke me of buying sheet metal from them though! I'll get yours next time.
    Any details on your door skins?
     
  18. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member

    Tinman and Pimpin' paint have it right on this deal. A flange is always going to be a problem on a low-crown panel like a door length patch. Cut it out, and I bet the crown comes right back. As tinman said, if you are working with a MIG, set it up so it is about as hot as you can go without blowing holes and with the feed fairly short for the panel your working. Do individual tacks set up like this slowly and skipping many inches at a time all the way across the panel stopping to hammer each as quickly as you can. As you weld, each tack will want to shrink as it cools - the quick hammering stretches the metal back to neutral to kill the shrink induced warp. after the first pass I would stop for a moment and gring just the tops of the weld that you already done and recheck for warp. If you have any, find it's starting point and hammer on dolly for a bit to cure it. DO THIS WHOLE DEAL SLOWLY! Let things cool and don't pile too much weld tacks in too close an area at one time and all will be well.
     
  19. rawcjw19
    Joined: Oct 8, 2012
    Posts: 581

    rawcjw19
    Member

    When you guys put the skins on. Do you weld the seam before folding the edges over?
     
  20. pimpin paint
    Joined: May 31, 2005
    Posts: 4,937

    pimpin paint
    Member
    from so cal

    Hey,

    I usually turn the flange, and tack the skin in a few spots, then rehang the door to check my fit PRIOR to welding out the patch/skin. This method allows me to make any adjustments necessary, to get a dead nuts fit up on my shut lines between the A, B posts the Rocker & the Cant rail. If I were to just weld up the patch/skin I might find the new part needs stretching/shaping to fit the door opening well and that would require alot of " sailor language '' to correct :D

    " Beware the irrational however seductive ''
     
  21. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    Good stuff!
    I don't think I will have much of a problem tacking the skin on but there is such a dip in the existing skin (both doors) that creates the problem. I took some pictures today but, for some reason, my phone won't send them. I'll give it another go with the camera tomorrow so you guys can see what I'm working with.
    Just for S&Gs, I put a piece of 1/2 square tube behind the existing skin. It wouldn’t push the dip out....
    Depending on when ems is coming out with a full skin from the window down. I may go that route but I really need to get the doors done before summer. Too much to do outside when the weather is warm!
     
    Last edited: Mar 19, 2013
  22. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    If you go to my pictures you can see what I am dealing with.
    Thanks
     
  23. tinmann
    Joined: Nov 11, 2005
    Posts: 1,588

    tinmann
    Member

    I went to your profile page and had a look at your door pics. That is quite the dip. How tall of a patch do you have to install? Your pics don't show the face of the doors. I wonder if you could install some crude wood blocking in the door to get the crown close enough for the initial tacks. It's amazing how a few tacks will hold an otherwise floppy panel to where it needs to be. Take the wood out as soon as you can after tacking. My only other suggestion is that when you start to tack, you have to maintain overall shape to within less than 1/16" of where you need it or all is lost. I've heard guys say they will deal with distortion later. It can't be done that way.
     
  24. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    Yes, I could block it or put in a stiffiner. Does the metal need to be streached or shrunk in order to flatten it? If I weld an planish will that stretch it flatter?
     
  25. Cut off the step flange and see how it looks. If you not willing to do that then yes you'll have to stretch. You'll be pissing against the wind. The step flange work hardens the metal. Good luck.
     
  26. pimpin paint
    Joined: May 31, 2005
    Posts: 4,937

    pimpin paint
    Member
    from so cal

    Hey,


    " if '' I'm readin you photos correctly you've got bigger issues than the patch & flange areas of that door! How much mud did you remove from the old repair?:eek:

    By any means necessary, block or clamp up the area @ the butt seam to normal contour, once welded, you can drop back and shrink or stretch the various areas of the skin that need correction above your patch. Tryin to straighten the skin before it's welded would, as pointed out above, be a bit like pissin into the wind, and wonderin why you got wet;)
     
  27. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    like pissin into the wind, and wonderin why you got wet
    Believe me, it wouldn't be the first time! :D

    Thanks for the help.
     
  28. brassspike
    Joined: Dec 24, 2007
    Posts: 169

    brassspike
    Member

    I finally got some time to work on this. I cut the flange off and butt welded the two together. As noted, the dip got worse but not too much. Now I need to work the metal.
    I have a srinking hammer and dolly ordered. Do I need to start to srink the metal at the seam first? Middle or ends? On dolly or off?
    Thanks for your time....I'm trying to learn as I go. :eek:
     

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  29. MP&C
    Joined: Jan 11, 2008
    Posts: 2,477

    MP&C
    Member

    To help explain what is happening there, most doors are going to have a slight crown from front to back, and well as top to bottom. If you were to look at the profile of this crown, it would resemble an arc. Now, when you weld the panel, as it cools the molecular structure realigns more tightly as it cools, causing the weld and the heat affected zone on either side of it to shrink.. Looking back at our "arc", if the weld along an arc shrinks any at all, the arc will tend to form more of a straight line. This is why welds will pull into a valley, you are losing the crown. You will need to fix the SHRINKING that has occurred by planishing, or STRETCHING the weld and HAZ using on-dolly. More shrinking of something already shrunk does not fix the issue.

    Many guys will look at how much the panel has moved and automatically think it has stretched. This is not the case.
     
    Last edited: Apr 1, 2013
  30. Mindover
    Joined: Jan 18, 2009
    Posts: 1,644

    Mindover
    Member
    from England

    Doing decent repairs is a process, if you don't start out right it will not end up right. First off is where you put your joints, chose the right place to join and you will save a lot of work. All butt welded joints should have as perfect a joint as possible between the two parts before welding starts to minimize warpage. Then there is the type of welding you use, mig welds are very hard to finish. Gas or tig are easier. If you use the right method distortion can be kept to a minimum. Finally there is an understanding of what you need to do to correct any distortion caused by the welding process.

    [​IMG]

    Choosing the right place to put the joint, the right welding process and technique will give you a weld that can easily be metal finished. The weld above was done with O/A. This method is very easy to learn.

    David
     
    Last edited: Apr 1, 2013

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