Mig welding auto panels in Place on vehicle

[mulugod]

hey guys,,,I know this is an old subject for most all of you but,,
I am attempting my first auto panel restoration and I need some basic info.
I want to cut old panel sections out on the vehicle and mig weld the new panel on . I have obviously never done this before.
I have asked this question once before and many ideas were presented back to me concerning whether or not to leave the Battery connected while welding. However,,, I did not get any concrete tips on doing the welding on the panels in place on the vehicle.

I assume there is no problem doing so given all the general precautions regarding keeping the gas tank well insulated from sparks, do not weld if fumes are present,use some backing materials to prevent excess sparking,etc.

Any professional input is welcome.

Oh yeah,,,humor and sarcasm is OK too,,, as long as the advice is good!

Real determined to progress my skills!!!
Mulu

Miller Dynasty 200DX Tig/arc
Millermatic 180 Mig
Miller 375 Extreme Plasma
Victor OX/acetylene
Cutting and grinding tools enough for newby shop

[Old Sporty]

Personally, if I was doing it, I would remove the fuel tank to be absolutely safe. With the proper precautions, however, you can weld panels with the tank in place. People do it all the time.

As for welding the panels, I suggest butt welding the patches with spot welds starting at 3/4 to 1" apart and alternating sides. This will help keep distortion to a minimum. Keep doing this until the seam is welded completely, planish if needed, grind, prime, paint. Try to fit your replacement panel as closely as possible. This will make it go a lot easier.

One nice thing about it, if you're not happy with your first attempt you can cut it out and redo it.

Enjoy.

[87SS]

Personally, if I was doing it, I would remove the fuel tank to be absolutely safe. With the proper precautions, however, you can weld panels with the tank in place. People do it all the time.

As for welding the panels, I suggest butt welding the patches with spot welds starting at 3/4 to 1" apart and alternating sides. This will help keep distortion to a minimum. Keep doing this until the seam is welded completely, planish if needed, grind, prime, paint. Try to fit your replacement panel as closely as possible. This will make it go a lot easier.

One nice thing about it, if you're not happy with your first attempt you can cut it out and redo it.

Enjoy.

This is exactly how I patched a door on my car this past weekend. Never really did a patch panel before and it came out really nice. Had some issues with grinding the welds down, still need some practice there but alternating small spot welds around until all the gaps are covered was pretty straight forward. Good luck.

[Hankl]

Mulu,

Besides the safety issues, you'll need to decide what process you'll use for joining the panels. If you use the Mig, it's going to be a lot easier using .023 wire than .030 or .035 wire. The smaller wire allows you to weld with better heat control than the thicker wire. With the Tig, while more time consuming than Mig for distance traveled, it would give you a weld that is more planish able than the Mig weld. Here is a really good article on this procedure.http://www.musclecarrestorations.com...eet-metal.html

Hank

[mulugod]

Thanks for all of your suggestions, safety, and technical advice!!

This is such a great site for us newbys to get feedback!!
Sorry if anyone was confused by the 2 different posts I accidently submitted!

I feel more confident to proceed with your good advice!
MULU

[MMW]

Be careful when grinding as you can do just as much damage/warping with to much heat buildup while grinding. Grind it a little at a time so as not to let it get to hot. Also when grinding sparks travel all over & will stick to paint & glass. Watch where sparks are going. --- Fit up is very important. No gaps to fill is good. Take your time fitting the panel correctly.

[Marcel Bauer]

As a general rule it is good to disconnect the battery.

[c wagner]

As a general rule it is good to disconnect the battery.

Yeah we've been over that topic here before. I once asked a portable welder with a steel work plate mounted to his truck with no isolation strips (wood, rubber, plastic) if he disconnected his battery every time he welded on the work plate. Do you venture to guess what his answer was?! Of course not, that would take forever and he'd wear his cables out in a couple of weeks.
Just be smart about it, don't ground on the front bumper when your welding on the rear bumper. Electricity is lazy and takes the shortest route. If for your own piece of mind you want to disconnect the battery then by all means, it will only take you a few minutes and chances are you won't need to move the vehicle too many times (if at all) until the repair is complete.

[nfinch86]

YES Disconnect the Battery, or as i do I use a Surge Protector attached to the Battery Terminals this will Protect any & all of your computer parts. Norm:

[Sberry]

I welded on hundreds, maybe thousand, cars, trucks, pieces of equipment and never unhook, especially with newer cars, they are a pain to reset everything and sometimes don't run well after interrupting the power supply. As the man said, thousands of work trucks are used every day. There is a lot of hearsay on this subject but not only have I never had a problem I don't know anyone for a fact that has and I suspect anyone who has may have had issues disconnected or not.