Body Seams

[Jim Nilsen]

Originally Posted by elitecustombody

If you're going to smooth the seams, weld them,but if you don't mind seeing the ghost lines of the seams or worse ,cracks ,then you can use filler or seam sealer.

my .02 cents

The problem with welding is that the next crack you will get will be next to the weld and the metal will be fatigued enough to be hard to repair.The torture we put these car through can flex the body hard enough the crack and pull at the seams. Not all cars are built the same so some it matters and some it doesn't. Unibody cars tend to flex all over.

Leading the area is the best thing if you can keep from warping the panels and not have it run all over. if you know someone who knows how to lead you are ahead of the game.

I have not had one area of sealer done the way I have done it have the paint crack on the surface after 10 yrs.

[elitecustombody]

Originally Posted by Jim Nilsen

The problem with welding is that the next crack you will get will be next to the weld and the metal will be fatigued enough to be hard to repair.The torture we put these car through can flex the body hard enough the crack and pull at the seams. Not all cars are built the same so some it matters and some it doesn't. Unibody cars tend to flex all over.


Leading the area is the best thing if you can keep from warping the panels and not have it run all over. if you know someone who knows how to lead you are ahead of the game.


I have not had one area of sealer done the way I have done it have the paint crack on the surface after 10 yrs.

Jim, just wondering,you're stating that your seam sealer is somehow stronger than lead,brazing or welding?

If someone if planning on putting their car through extremes,they would have a cage,SFCs to make the unibody more rigid, and if the welds are done right,the seams will not crack if welded,simply take the time to not only run a bead on the exterior, but reinforce them from the backside and all corners,

Leading will still crack if seams are not reinforced,brazing and leading would be a better option if welding is out of the question.

[The WidowMaker]

elite, how would you recommend welding them. series of tacks like other sheet metal work? or would you go hot and deal with a little warpage? i have a chevelle, but am looking for what to do about the quarter to roof, quarter to filler above the trunk and the quarters to rockers.

thanks, Tim

[elitecustombody]

To keep warpage to a minimum tack every inch or so ,keep repeating till the seam is welded ,don't ever try to weld a seam in one shot. I usually have a air blower and use it after each tack to keep metal cool and eliminate any warping,just don't blow while welding .

[Jim Nilsen]

Originally Posted by elitecustombody

Jim, just wondering,you're stating that your seam sealer is somehow stronger than lead,brazing or welding?

If someone if planning on putting their car through extremes,they would have a cage,SFCs to make the unibody more rigid, and if the welds are done right,the seams will not crack if welded,simply take the time to not only run a bead on the exterior, but reinforce them from the backside and all corners,

Leading will still crack if seams are not reinforced,brazing and leading would be a better option if welding is out of the question.

I am saying the seam sealer is less likely to crack at the paint and that if you weld the seam you make the steel brittle and it can crack at the edge of the weld not at the seam anymore.

If you have a leaf spring car the loads on the rear panel and rear window areas take a lot of twisting loads, if you have a 4 link or other type of suspension the loads aren't transmitted though the quarter panels anymore. It really depends on the car if you can get away with welding seams, but the way we thrash our cars we put a lot of stress on the skin and even a 10 point cage won't stop some of it from still happening.

Most of the high end cars just use regular factory style seam sealer and let you see them ,so it's not that big of a deal when you can see them compared to when the paint cracks and you get water in your seams.

I also seam welded my wheel wells, rockers on the pinchweld end so I didn't have to use seam sealer on them at all. The use of seam sealer was kept to a minimum so it would stop any chances of water getting up in the pinchweld.

Hope that makes it a bit more clear.


I made sure my seams were hammered and dollied to the exact shape to match each sides on all the pinch welds and I added lots of extra spot welds to make it all stronger. Putting the extra spot welds in put the stress of the load at a different angle and allows the corner strength of the bend on the pinch weld to work for you.