Rounded corners or 90 degree corners when mig welding a patch in?

MJM

MJM

Promoted Users
Which way is better, or perferred, when mig welding a patch in, rounded corners or square 90 degree corners?

Thank you,
 
MIG welding rounded is better. If you can do it. TIG and Gas welding its not as critical. Like shine said tight fit/no gap is most important with them. MIG sometimes it's preferable to have a gap.when butt welding
MIG welding sheet you don't want to lay down beads. Skip around, tack weld, connect the dots.
 
Chris_Hamilton said:
MIG welding rounded is better. If you can do it. TIG and Gas welding its not as critical. Like shine said tight fit/no gap is most important with them. MIG sometimes it's preferable to have a gap.when butt welding
MIG welding sheet you don't want to lay down beads. Skip around, tack weld, connect the dots.
Click to expand...

What do you mean 'if I can do it ?" I'll have you know I've been doing vehicle body panel fabrication for at least 14 months. Chip Foose thinks I have a God given talent and wants me to pursue a career in metal fabrication, specializing in body panel patches.

This patch is a 3-1/2'' x 3" which will be butt welded with a mig welder. It's my understanding I would want a gap for full penetration so I have weld material to grind smooth.

If I was tig welding, there should be no gap.
 
Last edited:
shine said:
either , a tight gap is what's important,
Click to expand...

I've never mig welded a butt joint without a gap. Going to try it on some scrap metal and see if I get full penetration, and be able to grind the weld smooth and have a strong joint.
 
Last edited:
Chris_Hamilton said:
I know you are joking..... :p but what I meant was if the work or space allows it. Not if you personally could do it.:)
Click to expand...

Yes I have the room. I found out today the best way to not find body panel issues, is to not strip the existing paint off. I prepped the passenger side door jamb yesterday for epoxy and stripped the existing paint off of the driver's side today to find an issue. The door jamb striker metal is toast. Someone had done a terrible job welding it up for a repair and had literally 3/16" of filler covering it. Now I know why the striker post was indented into what I thought was metal.

I've taken pictures of the before and will be posting them in my restoration thread in a few days. I questioned the round corner to square corner because I have limited access to the backside of the striker metal. Limiting distortion will be a big help, so round it is unless I hear otherwise
 
Last edited:
MJM said:
I found out today the best way to not find body panel issues, is to not strip the existing paint off. I prepped the passenger side door jamb yesterday for epoxy and stripped the existing paint off of the driver's side today to find an issue.
Click to expand...
LOL. Check out @pugsy123 post about his quick scuff and shoot of 69 el camino.
This is how it always goes on older cars.
 
  • Like
Reactions: MJM
MJM said:
.......
This patch is a 3-1/2'' x 3" which will be butt welded with a mig welder. It's my understanding I would want a gap for full penetration so I have weld material to grind smooth.

If I was tig welding, there should be no gap.
Click to expand...


Where exactly on the vehicle is this patch going? (picture?)
 
MP&C said:
Where exactly on the vehicle is this patch going? (picture?)
Click to expand...

Door jamb

20220706_142913.jpg
 
I started prepping the area last night by pulling the dents out and grinding down the weld before cutting out the bad metal ( have not cut out the bad metal yet ), so I have a flat surface at the perimeter of the old metal to the new metal before welding.

20220706_151241.jpg
 
Last edited:
Is there a stiffener plate behind? Does it use a nut plate to attach the door striker? Is this spot welded in place or??
 
Last edited:
Was there a spot welded cage that held the nut plate in place or was it just free floating?

I would use the same thickness as what is there, which should be 19 gauge, but a thin 18 gauge (about .040-044) would work..

BTW, your dent pulling looks good. The reason I'm asking so many questions is to see the best place to put your seams....
 
  • Like
Reactions: MJM
If there were a cage that the nut plate dropped into and you needed to drill out spot welds to remove that, you may want the new patch large enough to take care of those drilled holes.. (for example)
 
You must log in or register to reply here.
Back
Top