instructions on welding in auto floor pan

Discussion in 'Paint and Body' started by grumpyvette, Jun 3, 2013.

  1. grumpyvette

    grumpyvette Administrator Staff Member

    heres a few basic tips from experience doing this a few times
    a good quality 130-140 amp MIG is almost ideal for body sheet metal welding jobs,its a darn good choice if your unlikely to use it on much more than auto sheet steel, and rarely over about 3/16" thick metal
    much superior to the cheap flux core wire welders I see a few guys using.


    http://garage.grumpysperformance.com/index.php?threads/under-car-safety.26/

    http://garage.grumpysperformance.com/index.php?threads/floor-pan-replacement.10917/#post-47897

    http://garage.grumpysperformance.com/index.php?threads/welding-in-new-floor-pan.10735/

    http://garage.grumpysperformance.com/index.php?threads/welding-auto-sheet-metal.4604/

    http://garage.grumpysperformance.co...eresting-tool-for-auto-body-panel-work.12571/

    http://garage.grumpysperformance.com/index.php?threads/pop-rivet-tools.2750/#post-46136

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    https://www.accessiblesystems.com/bul/4ke/4ked01.php
    http://www.welders-direct.com/mm5/m...t_Code=THA-W1003141&Attributes=Yes&Quantity=1

    http://www.welders-direct.com/mm5/m...e_Code=WD&Product_Code=907612&Category_Code=M

    https://www.weldingmart.com/lincoln-power-mig-140c-k2471-2
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    Ive used a friends lincoln mig several times on body sheet metal at his shop with good results, but remember as you turn the amps up the duty cycle goes down and the cool down time between welding sessions increases
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    http://www.welders-direct.com/mm5/m..._Code=WD&Product_Code=K2471-2&Category_Code=L

    keep in mind shield gas and wire selection,
    surface prep, plus experience,
    all effect the weld quality,
    and the larger amp migs can generally do the jobs that the lower amp rated migs can do, while the larger amp migs can also do the thicker stuff that out of the lower amp migs effective range, one other difference is DUTY CYCLE, the larger amp rated migs can be used almost constantly at the lower amp settings without over-heating or needing cool down time, something not generally true in the lower amp range migs

    http://garage.grumpysperformance.com/index.php?threads/shield-gas-selection-for-welding.1108/

    http://garage.grumpysperformance.com/index.php?threads/mig-wire-selection.1283/

    http://garage.grumpysperformance.com/index.php?threads/mig-or-tig.72/

    http://garage.grumpysperformance.com/index.php?threads/most-versital-shop-welder.1594/
    (1) DON,T EVEN CONSIDER a flux core welder but if forced to use one..
    and remember that flux-core requires reverse polarity compared to MIG.

    (2) a good mig or TIG is far better, but before you start talk to a couple local welding supply stores about the settings for gas flow rates wire diam. and related weld info

    (3) don,t cut out the damaged area UNTIL the cars firmly supported on at least 6 jack stands, one on each corner and one center span,on each side frame , you need full support, you don,t want the frame or body moving from its original location while the floor pans removed and replaced

    viewtopic.php?f=27&t=672&p=28211&hilit=JACK+STANDS#p28211

    viewtopic.php?f=60&t=7794&p=26707&hilit=eastwood#p26707

    viewtopic.php?f=60&t=1108

    viewtopic.php?f=60&t=10601

    viewtopic.php?f=60&t=4604

    viewtopic.php?f=60&t=441

    and before you start get the actual replacement panels in your hands and look at what your dealing with carefully, you want the panel to be at least 1" larger in all dimensions than the hole its going to cover,inspect carefully before making any cuts, so you don,t cause extensive extra work,and so you can use cleco pins and welding can be easily done. and the parts fit correctly before you even use and clamps or fasteners

    (4) clean metal welds far easier so get a good die grinder and 1/2" chuck electric drill with a rotary wire brush

    (5) measure VERY carefully and look at both sides of the panels before cutting or welding

    (6) cleco pins or pop rivets to temporarily hold the panel in place help a great deal, cleco pins, if your not familiar with them are a spring loaded temporary rivet style fastener,they come in packs of 20, and 100, buy a pack of 100, 1/8 inch and the matched pliers and several drill bits you drill a hole of a matching diameter to the pins you select thru the two panels of sheet metal and the spring loaded pin holds them together tightly so they can,t move , you spot weld rather extensively , in a weld 1/2" skip 2" repetitive series so you don,t heat warp the panels, this requires you to go around the edge in a circle about 5-6 rotations before the entire edge of the panels welded.then go back and remove the clecos




    http://www.rivetsonline.com/cleco.html

    http://www.summitracing.com/parts/sum-g1852/overview/

    http://www.summitracing.com/parts/aaf-a ... /overview/

    http://www.mig-welding.co.uk/forum/show ... php?t=7845

    viewtopic.php?f=61&t=9302&p=33608#p33608

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    use the replacement panel as a pattern , leave enough metal to use cleco pins
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    a plazma cutter, saws-all or die grinder will be required

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    USE CLECOS AND TACK WELD DON,T TRY TO RUN A CONTINUOUS BEAD, or youll heat warp panels

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    AFTER YOU WELD GRIND SMOOTH BEFORE PAINTING and use a good rust preventive paint
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    http://www.millerwelds.com/resources/ar ... C-Welding/

    http://www.hotrod.com/howto/42644_repro ... s_install/

    http://www.millerwelds.com/resources/co ... loor-panel

    http://www.webring.org/l/rd?ring=classi ... elding.php

    http://www.chevelles.com/techref/ftecref6.html

    http://www.weldingtipsandtricks.com/tig ... iques.html

    http://wn.com/lesson_on_welding_thin_steel,

    http://www.mig-welding.co.uk/removing-floor.htm
     
    Last edited by a moderator: Feb 7, 2019
  2. DorianL

    DorianL solid fixture here in the forum Staff Member

    WOW!!!! THANKS!!!! FANTASTIC!!!!!!!
     
  3. grumpyvette

    grumpyvette Administrator Staff Member

    youll want to carefully measure the cars body sheet metal gauge and ideally get replacement floor pans made from the same or heavier gauge metal,
    youll tend to get better welds if the mig wires on the smaller end of the range for the gauge of sheet metal being welded.
    DON,T IGNORE the fact that MIG WELDING REQUIRES A SHIELD GAS, welding without that makes the weld less solid and messy, harder to clean up and surely less solidly connected.

    THIS MAY ALMOST LOOK LIKE A EASTWOOD COMMERCIAL, but keep in mind theres other similar tools from MILLER ,LINCOLN ETC.
    and NO! YOU DON,T NEED ALL THE TOOLS OR THE BEST OUT THERE!
    what you NEED is the experience and instruction from a more experienced guy whos willing to teach you the skills and a firm understanding of how the tools are used, duty cycles and the capability's and limitation's and proper use of the tools, BEFORE YOU PURCHASE WHAT YOU NEED IN YOUR SHOP

    nibbler shears
    https://www.youtube.com/watch?v=R9udH1CXxpc
    http://www.eastwood.com/electric-metal- ... hears.html
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    http://www.zoro.com/i/G3239555/?utm_sou ... aQodEKQAgA
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    plazma cutter
    https://www.youtube.com/watch?v=0OLn6ccUB4A
    http://www.eastwood.com/eastwood-plasma ... aQodAQMABw


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    tig welder
    http://www.eastwood.com/tig-welders-eas ... aQodLkAAAg

    http://www.eastwood.com/ew-tig200-versa ... ?reltype=3

    https://www.youtube.com/watch?v=Zd-u-nTL0yM

    https://www.youtube.com/watch?v=AtAEPuPbWKM

    https://www.youtube.com/watch?v=GbQTyRT86Gg

    http://www.welders-direct.com/mm5/merch ... ry_Code=TW

    https://www.youtube.com/watch?v=aIyu-63ruMU

    https://www.youtube.com/watch?v=dWZQeSWoNQ8

    READ THE RELATED LINKS

    viewtopic.php?f=60&t=1283

    viewtopic.php?f=60&t=1108

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    a 140 amp lincoln MIG welder you can buy for under $500 will make good sheet metal welds if properly set up,
    but a 180 amp mig ,from miller or lincoln, is going to handle FAR more applications and be more versatile in the long run, so ID advise spending a bit more up front, youll not regret it later

    http://www.welders-direct.com/mm5/merch ... Code=l-mig

    http://www.welders-direct.com/mm5/merch ... Code=m-mig
     
  4. DorianL

    DorianL solid fixture here in the forum Staff Member

    I am very much looking forward to learning this skill.
     
  5. grumpyvette

    grumpyvette Administrator Staff Member

    mig welding has gotten easier to do correctly over the years , but even back in the early 1970s my college engineering class instructor used to say

    " they can teach retarded monkeys to mig weld so theres at least some hope for you guys"


    political correctness had yet to make an appearance back then, and you were required to succeed, at and know what you were doing before you got a degree

    read this thread
    viewtopic.php?f=60&t=9745&p=36661#p36661

    heres a good basic link, but theres dozens more instructional links in the welding section on the site

    http://www.millerwelds.com/resources/basicMIG/index.htm

    most guys find the .023 wire and a MIG welder with a full tank of shield gas and a well cleaned wire brushed surface is required to get a solid weld

    GET A GOOD HELMET/FACE SHIELD,
    viewtopic.php?f=60&t=1669
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    yes its amazing what youll learn reading the linked info

    http://www3.nd.edu/~manufact/MPEM%20pdf_files/Ch12.pdf

    https://engineering.purdue.edu/~jliu/co ... ds_S11.pdf

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  6. grumpyvette

    grumpyvette Administrator Staff Member

    btw Ive replaced enough panels that
    I,M FORCED TO POINT OUT THAT YOU NEED TO BE VERY CAREFUL INSPECTING THE AREAS YOUR GOING TO BE DEALING WITH AND USE THE CORRECT TOOLS AND HAVING THE CAR UP ON (6) 12 TON RATED JACK STANDS or a LIFT ,SO YOU HAVE AN EASY 24"-TO-30" CLEARANCE UNDER THE CARS FRAME SO YOU CAN ACTUALLY USE A MECHANICS CREEPER FOR ACCESS TO THE PANELS FROM BOTH SIDES HELPS.
    drilling a few holes with a 1/8" drill along the proposed panel cut-out line, every few inches, helps you see where youll be cutting from both sides of the panel, and helps you visualize potential screw-ups
    careful use of a plazma cutter is ideal for panel removal, you might even see if you can rent one if you don,t own a plazma cutter as they make the job much easier.

    http://www.eastwood.com/tig200dc-and-ve ... o-kit.html

    http://www.eastwood.com/versa-cut-60-an ... o-kit.html


    yes you might think you don,t need that much access or need to inspect the panel from both sides ,but then you eventually find pesky little components like brake lines, fuel lines exhaust pipes, electrical cables under sill panels , and a couple dozen other components get screwed up during the panel replacement process.
    BTW if you decide to use a saws-all tool don,t even consider the cheap and totally useless imported version,s from HF, I was given one as a gift, and it stalls and binds and locks up, with almost no resistance. theres several versions, a couple of my friends also have some,of those saws-all saws from HF .. none seem to work well, in my experience.

    http://www.harborfreight.com/6-amp-reci ... 65570.html

    http://www.harborfreight.com/75-amp-rec ... 69067.html

    NOW don,t think all reciprocating saws are junk, my neighbor has a milwauulkee saws-all that works reasonably well.
    http://www.cpomilwaukee.com/milwaukee-6 ... ing%20saws

    useful info
    viewtopic.php?f=27&t=2094&p=26084&hilit=plazma#p26084
     

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