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Technical modal a frame boxing

Discussion in 'Traditional Hot Rods' started by 410merc, Feb 26, 2016.

  1. 410merc
    Joined: Mar 31, 2014
    Posts: 69

    410merc
    Member

    hi everyone , I am just starting to box my frame for my 30 tudor , here is my question and it is a very simple one , would 1/8 inch steel be heavy enough for frame boxing ,I am planning to use a small block chevy , what do you guys think ?
     
  2. seb fontana
    Joined: Sep 1, 2005
    Posts: 8,442

    seb fontana
    Member
    from ct

    I say yes but then you will get the argument that 3/16 is best as it is closer to the original frame thickness..
     
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  3. trollst
    Joined: Jan 27, 2012
    Posts: 2,108

    trollst
    Member

  4. 410merc
    Joined: Mar 31, 2014
    Posts: 69

    410merc
    Member

    I think your right , because I noticed there are a lot of 1/8 inch frame box stuff on ebay so they must think it works ok
     

  5. Yes
     
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  6. woodiewagon46
    Joined: Mar 14, 2013
    Posts: 2,269

    woodiewagon46
    Member
    from New York

    1/8" will be fine, sorry to disagree seb, but Model A frames are not 3/16" thick.
     
  7. Woodie, I think My frame is 3/16" is it not?
     
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  8. I just mic'd my bare frame at 0.160". Not quite 3/16" but .125" would be ok if I were doing it.
     
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  9. 410merc
    Joined: Mar 31, 2014
    Posts: 69

    410merc
    Member

    boy thanks guys ,should I lay the pieces flush, or set them in a bit
     
  10. aaggie
    Joined: Nov 21, 2009
    Posts: 2,530

    aaggie
    Member

    1/8" is fine and set them in a bit because if you grind the welds to make pretty you lose strength. Some people use thicker material for boxing because it give a little extra thickness to drill and tap various mounting screws for things like brake line clips.
    Think about where you may plan to attach things and weld in captured nuts to the inside of the plates before welding.
     
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  11. Let see , that's what about .025 short less than 1/32" pretty close to 3/16".
     
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  12. Don's Hot Rods
    Joined: Oct 7, 2005
    Posts: 8,319

    Don's Hot Rods
    Member
    from florida

    I used 3/16 on mine for two reasons. I overbuild everything, and the extra wall thickness is easier to drill and tap threads into for non structural things like brake lines, wires, etc.

    More important than the boxing is the crossmembers though. Even boxed, an A frame will twist like a pretzel unless you put proper X or K crossmembers in to eliminate that twist.

    Don
     
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  13. woodiewagon46
    Joined: Mar 14, 2013
    Posts: 2,269

    woodiewagon46
    Member
    from New York

    I think where the confusion in the measurements comes from, is because when Ford built the Model A frame they did not use dimensional steel such as 1/8" or 3/16". The frame rails were stamped from sheet steel, formed in to a channel and then riveted together. I just put a mic on one of mine and it ranged between .152 to.160 which is 9 gauge, U.S. standard. I have seen both 1/8" and 3/16" frame boxing kits available, I know Chassis Engineering uses 3/16" on their kits. Both sizes will work for you.
     
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  14. seb fontana
    Joined: Sep 1, 2005
    Posts: 8,442

    seb fontana
    Member
    from ct

    I didn't say they were 3/16; I said they were close to 3/16..I already said 1/8 would be ok..
     
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  15. 410merc
    Joined: Mar 31, 2014
    Posts: 69

    410merc
    Member

    when I was cleaning up the frame I noticed on the drivers side of it between the front crossmember and the middle crossmember it has a slight dip about 1/4 inch measuring at the top of the frme where the first body mount bolt goes , I can't see where it sprung or buckled , so how close are they , should I attempt to straighten it a little or jusy leave it
     
  16. mgtstumpy
    Joined: Jul 20, 2006
    Posts: 9,214

    mgtstumpy
    Member

    3mm plate is close enough to 1/8" and used all the time down here in conjunction with a stout 'K' member. The legs are run forward from each rear side rail to centre member forming a 'K' and a mandatory requirement down here.

    When fully welded the frame with 'K' member is stronger than just a frame with boxed outer rails and a single centre member for transmission like this frame.

    This frame will torsionally twist.
    bbbb.jpg

    These frames won't twist due to 'K' member and legs. http://www.dagelsstreetrods.com/super_x_crossmember.htm
    upload_2016-2-28_9-23-33.jpeg
    upload_2016-2-28_9-23-52.jpeg
     
    Last edited: Feb 27, 2016
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  17. The dip is very near where the original rear motor mounts are and where such frames typically sag. the Model A restoration books have articles on how to correct the sag. It might be wise to do that before you go further. A sag in the frame will affect hood and body fits.

    "How to Restore Your Model A, Volume 2" is the first book I looked at with a specific piece on straightening the frame. Brattons.com sells the book, as do many Model A parts suppliers. I just hopped to their web site and they seem to have TOC's on a number of the books they sell.
     
    Last edited: Feb 27, 2016
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  18. 410merc
    Joined: Mar 31, 2014
    Posts: 69

    410merc
    Member

    boy thanks Russ B that explains it right there , now to correct it , I was thinking some good heavy irons and a hydraulic jack and a piece of heavy angle iron so I don't bend it wear the jack goes
     
  19. rusty rocket
    Joined: Oct 30, 2011
    Posts: 5,053

    rusty rocket
    Member

    It might have been close to 3/16 but after 80 plus years of rust and gunk I bet its a bit thinner, 1/8 would be just fine.
     
  20. 55willys
    Joined: Dec 7, 2012
    Posts: 1,711

    55willys
    Member

    Last one I built used a Dagel's un boxed frame and x member. His frame rails are thicker than stock. I was quite satisfied with it. My sort of stock frame had questionable suspension mounts made of flat bar, cracked front cross member, notches cut out for exhaust clearance and twisted unboxed frame rails from the torque of a 383 Chrysler. I was able to salvage the rear cross member out of it. I also had to relocate the brake pedal mount to the stock location on the Dagel's frame due to it being set up more for a SBC than a Flathead.
     
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