LEADING A JOINT or MIG WELDING THE JOINT ?

Hey Guys

I just did my first pratice over-lapping sheet metal joint.

1st. Flanged on side of the practice piece.

2nd. Cleaned the area and punched spot weld holes on one piece of the practice piece.

3rd. I tack (mig welded) the spot weld holes to hold the over-lap joint together.

4th I left a 1/4" gap in the over-lapping joint to be filled in with lead free lead.

5th. I tined the joint area.

6th. I went in and filled-in the gap making sure I left a little hump of lead throughout the joint.

7th. ground down the lead and made it even with the exsisting metal.

Well to my surprise I was disappointed. A thin line appreared throughout the leaded joint. I believe it was one side of the over-laped joint line where the gap began.

Although its me first lead free lead I did pretty well and watched me heat.
But again I could figure-out how the heck that thin line appreared in the joint.

O.K. ENOUGH !
Questions Please:

1. Is it better to start practicing doing complete mig weld joints: (Over-lapping & Butt Joints) instead of LEAD JOINT ?

2. Or should PRACTICE MORE on the lead joints ?

Thanks Guys
GOD BLESS

Schooner

I only spot weld an overlap if I am going to leave the end open and seal it with seam sealer.

If I am going to bondo or lead {without lead} over a weld, I never ever leave part of the metal un-welded, I make it a solid weld. Becaue the metal alway's moves, thus causing lines and or cracks etc... That's just me and my opinion though, not yet written into law

Originally Posted by FEandGoingBroke

I only spot weld an overlap if I am going to leave the end open and seal it with seam sealer.

If I am going to bondo or lead {without lead} over a weld, I never ever leave part of the metal un-welded, I make it a solid weld. Becaue the metal alway's moves, thus causing lines and or cracks etc... That's just me and my opinion though, not yet written into law

Hey FEandGoingbroke

From what I've read you I believe you like to weld instead of lead. I did my first practice over-lapping joint and everything was going fine.

I did the following:

1. Wire brushed the joint area.
2. Tack welded the joint area leaving an 1/4" gap to be filled in with lead.
3. Tined the area and leaded with lead free lead.

Everything was looking good until
I stated grinding down the l/f/lead and low and behold I don't know why the heck that LINE came from; running right down the joint.

I didn't uncut the lead joint making sure I didn't the original sheet metal on both sides of the lead joint.

A HAIR LINE right down the entire joint ! Damn.
Butt I got 2 remember that was my first lead over-lapping joint.
I had lots of control and watched me HEAT and like I said everything look GREAT. UNTIL ! ! !

Any ideas where the heck I went wrong
GOD BLESS

Schooner

I'm curious why no butt weld in this particular area? I read the previous post too and even with body flexing I would think the repair would hold since the weld is stronger than the parent metal. Plus I would think It would allow moisture to get in from the underside. Thinking about it, it just doesn't seem right.


Someone care to enlighten?

I've never re-leaded new stuff, only touched up old stuff.
I have no clue without watching you or looking at the spot as to why the line appeared.

weld it solid and lead it like Fe says. Hes spot on

Originally Posted by BlueOvalBandit

I'm curious why no butt weld in this particular area? I read the previous post too and even with body flexing I would think the repair would hold since the weld is stronger than the parent metal. Plus I would think It would allow moisture to get in from the underside. Thinking about it, it just doesn't seem right.


Someone care to enlighten?

Hi BlueOvalBandit

I try to answer your questions ' . . . why no butt weld in this particular area?

I just completed an over-lapping joint with lead free lead. I lead both side of the practice piece. Everything came out fine EXCEPT!

After grinding down the lead joint a THN LINE appeared throughout the lead joint. Hummm! Like I said everything was looking good. I really don't know what the heck went wrong.

Although, this was my FIRST lead free lead over lap joint. Maybe I'll do more practicing with the leaded joint.

At the present time I tried a BUTT JOINT with mig. Everything is good well.
I watched me heat and NO WARPAGE appeared.
I watched me heat and the practice piece hasn't warped.

Next I'll grind down the weld and see how it looks.

I think when I'm ready to cut out the rust on that fender and put in my patch panel I'll BUTT WELD IT. It seems that most all the pros on this forum do it that way and who am " i " not to follow in their steps.

Hope that help you guy.
GOD BLESS
Schooner