Help with MIG welding body panels? - JeepForum.com

Reply
 
LinkBack Thread Tools
post #1 of 47 Old 12-09-2011, 07:00 AM Thread Starter
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert
Posts: 17,410
Help with MIG welding body panels?

Hey guys,

I'm brand new to welding. Using a Lincoln 140 with .024 solid wire and 75/25 argon/CO2 shield. Power and wire-speed is set per the chart on the welder for 16 ga. mild steel and gas.

I can run nice clean beads, with good penetration, all day long on a flat sheet with no seam. But, when I butt two pieces and try to weld them together, I get blow-thru, especially at any gaps in the butt larger than say 1/32"

I'm aware you should only weld short segments at a time (about 3/4-1"). I've also tried the start/stop spot weld technique, which is better, but I still have trouble at the gaps. I'm going to try using a copper "heat sink" behind the weld, today, to see it that helps.

Any other suggestions?

Thanks,

Matt

Attached Thumbnails
Weld1.jpg   Weld2.jpg   Weld3.jpg   Weld4.jpg   WeldBolwThru.jpg  



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Matt1981CJ7 is online now  
Sponsored Links
Advertisement
 
post #2 of 47 Old 12-09-2011, 07:10 AM
BioTex
Registered User
2006 TJ Wrangler 
 
Join Date: May 2008
Location: Alpine, Tx.
Posts: 3,173
When I get that blow through, I turn up the wire speed a tad. It cools the puddle a bit. The copper heat sink should help also.

'85 CJ7, BDS 4" lift, 1" Body lift, 33x12.5, Shrockworks Sliders, 304 V8 with RV cam., T-176, D300, Dana 30, AMC 20.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

06' TJ Rubicon, 4" R.C. springs, BFG/AT 35s M.C. 6" fenders, rockers and surrounds, Currie front & rear adj. tracbars, tattons DC rear shaft, adj. upper - lower CA's. Bilstein 5100's

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Current project. Stroker/FI ?
1990 MJ Comanche 4.0L AX15/np231
BioTex is offline  
post #3 of 47 Old 12-09-2011, 07:18 AM Thread Starter
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert
Posts: 17,410
BioTex,

Well, that's one thing I was doing wrong. In my small mind, reducing the wire speed would cool things down. I'll try going the other way with it.

Matt


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Matt1981CJ7 is online now  
post #4 of 47 Old 12-09-2011, 07:19 AM
82JeepCJ7
Registered User
1982 CJ7 
 
Join Date: Jun 2010
Location: Marysville, WA
Posts: 5,467
You need to add a backing strip in behind the patch panel to make it a lap joint on metal that thin with that big of a gap. You can tack the strip in before putting the patch panel in. Doing that will save you a ton of time and frustration when working with thin metal. Since you can get to the back side, you can put a 1/2" wide strip behind the joint and tack it in. Take your time and allow the metal to cool between spot welds. Also, hard wire does not like any rust or deteriorated metal. If you have to go bigger on the patch panel to get into some good meat, then that's what it takes. I sand blasted my replacement tub and any rusty metal that blew away, I did not want in there anyway. I ended up with some larger patch panels, but I knew in the end that those would be solid and the material around the welds would not crack a few years down the road. And as always with welding..... Practice, practice, practice.

Beat it to fit, paint it to match!

Wheel, Wrench, Repeat.
82JeepCJ7 is offline  
post #5 of 47 Old 12-09-2011, 07:28 AM Thread Starter
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert
Posts: 17,410
82JeepC17,

I was into good metal all the way around my patch. It sounds like the heat sink and a backer strip do about the same thing.

I may try the backer strip, since I can't find a scrap piece of copper, and the wife won't let me cut up one of her serving trays.

Thanks,

Matt


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Matt1981CJ7 is online now  
post #6 of 47 Old 12-09-2011, 07:35 AM
BioTex
Registered User
2006 TJ Wrangler 
 
Join Date: May 2008
Location: Alpine, Tx.
Posts: 3,173
The draw back to a backing strip welded in is that you now have a seam on the back side that will hold dirt and moisture. It will rot out very fast. The idea is to leave a smooth finish on the back side so it will dry out fast after getting wet. You don't want any ledges for anything to grip to.

'85 CJ7, BDS 4" lift, 1" Body lift, 33x12.5, Shrockworks Sliders, 304 V8 with RV cam., T-176, D300, Dana 30, AMC 20.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

06' TJ Rubicon, 4" R.C. springs, BFG/AT 35s M.C. 6" fenders, rockers and surrounds, Currie front & rear adj. tracbars, tattons DC rear shaft, adj. upper - lower CA's. Bilstein 5100's

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Current project. Stroker/FI ?
1990 MJ Comanche 4.0L AX15/np231
BioTex is offline  
post #7 of 47 Old 12-09-2011, 07:43 AM
Area.3.Fiftyone
Registered User
1996 ZJ 
 
Join Date: Sep 2009
Location: Kingston, Pa. 18704
Posts: 3,469
Take a piece of copper pipe and flatten it out for a backer.

You should be able to fill those gaps, they aren't that big. I would start at the bottom and lay a tack then slowly move your way up (after tacking the entire piece in place to prevent movement).

Gravity will help here and the bottom tack will hold the puddle as you progress upwards. If your heat is set right, you should be able to start the arc on one side and then pull the puddle across to the other good piece to bridge the gap.

Good luck!

79' CJ7 - 82' CJ8 - 94' YJ - 96' ZJ
Diagonally parked in a parallel universe.......
Area.3.Fiftyone is offline  
post #8 of 47 Old 12-09-2011, 07:53 AM
nichboy
Registered User
1985 CJ7 
 
Join Date: Feb 2010
Location: Oklahoma
Posts: 298
*Great thread*

Great pics Matt, keep the pics coming on your progress, i'm fixing to tackle the same thing.
nichboy is offline  
post #9 of 47 Old 12-09-2011, 07:54 AM Thread Starter
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert
Posts: 17,410
Stan,

You sure know your way around body work...smashing a chunk of copper pipe is a great idea, and it sounds like fun, too.

I still may use a backer in the area shown on my last picture, because I got a little aggressive with the grinder and I think I thinned the metal a little too much.

Thanks, I'll keep working at it until I get it right. I've got one more side to practice on. Thankfully, the areas around the Jeep logos are the only 2 spots on the entire tub that have serious cancer. The rest is all just surface rust that should sand off easily.

Matt


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Matt1981CJ7 is online now  
post #10 of 47 Old 12-09-2011, 08:19 AM
Area.3.Fiftyone
Registered User
1996 ZJ 
 
Join Date: Sep 2009
Location: Kingston, Pa. 18704
Posts: 3,469
No problem Matt.

I have been doing this for over 35 years and you learn quite a bit from trial and error.

79' CJ7 - 82' CJ8 - 94' YJ - 96' ZJ
Diagonally parked in a parallel universe.......
Area.3.Fiftyone is offline  
post #11 of 47 Old 12-09-2011, 09:06 AM
cbrogers
Registered User
 
Join Date: Jun 2006
Location: Yorktown, Va.
Posts: 15
You might also try the Tac,tac,tac method. Keep jumping around. The sheet metal is just too thin to do MIG welding on. If you had TIG you could do a bead. But for Sheet Metal the Multiple tac method works pretty well.

Start out spacing Tac's about 1" apart and then go back and weld 1/2 way in between. Continue to do this untill you are starting to get too much heat in one area. Maybe 3-4 passes. Then just jump around to other parts of the patch.

You will have to wait some times between rounds. You really do not want to put too much heat into the metal at a time. A lite breeze will help to cool but do not take heat out too quick with something like water. You can cause shrinkage issues too. Best if you can jump to another patch on a different area of the body, or take a quick break for a Soda.

Just remember to go slow with the heat. Much easier to do the patch once than to have to try and fix a Shrink/Stretch issue from heat.



Carl
cbrogers is offline  
post #12 of 47 Old 12-09-2011, 09:16 AM
CSP
Registered User
 
Join Date: Aug 2002
Location: Colorado
Posts: 15,884
Matt,
One of the best threads I've ever seen for patch panel installations. It's a long read, but worth it.

http://www.garagejournal.com/forum/s...ad.php?t=53534
CSP is offline  
post #13 of 47 Old 12-09-2011, 09:18 AM
ratjaw
Registered User
1972 CJ5 
 
Join Date: Dec 2005
Location: East Tennessee
Posts: 134
I've been doing the same thing on my 72 CJ5. I'm using a piece of brass from a truck radiator as a backer. Hold brass on back side with left hand and weld with the right. I'm using the exact same welder and gas combo. I'm new to welding so this has been a learning experience for me. Small spot welds skipping around to prevent too much heat build up is the key. Grind joints smooth when finished. With practice it's hard to tell old metal from new. Take your time and enjoy your results. Good luck and keep us posted.

Jeep..... The best thing to come from Ohio since aviation.

Resurrection Build Thread 1972 CJ5

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
ratjaw is offline  
post #14 of 47 Old 12-09-2011, 09:33 AM
LargeAl
Dirt Gobbler
 
LargeAl's Avatar
1979 CJ7 
 
Join Date: Oct 2001
Location: Byron, GA
Posts: 145
Magnetic copper backer plate

You might want to try one of these from Eastwood...


I believe Harbor Freight also has something similar if there's one close by.


God Bless Our Troops...


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
LargeAl is offline  
post #15 of 47 Old 12-09-2011, 09:46 AM Thread Starter
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert
Posts: 17,410
Carl,

I used the tac method on the panel shown. It was working beautifully to begin with, but I think I got impatient and rushed it towards the end. The small panel got too hot and wouldn't hold the edge on the last several tacs. Lessen learned.

CSP, if I read another how-to, or watch another youtube, I think I'll go blind. Sometimes there's no substitute for just jumping in and getting your hands dirty.

Overall, I'm fairly pleased with my first body patch attempt. The straight-edge indicates that everything stayed flat and flush. I shouldn't have to use much putty at all. If I can get these last few holes closed up and ground flat, I should be able to move to the other side.

Matt


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Matt1981CJ7 is online now  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Spot welding new side panels nolefansjeep Jeep CJ Forum 11 11-11-2011 09:41 AM
Body Panels kluman Jeep CJ Forum 5 05-27-2010 12:28 PM
body panels careed Jeep CJ Forum 8 06-08-2009 11:14 AM
72 Body Panels Glock23NC Jeep CJ Forum 2 03-23-2009 04:10 AM
welding replacement panels bfr Jeep CJ Forum 1 12-16-2008 04:28 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome