This is not a recommendation to leave lead in your seams or not, its just for your information.

Most of you remove the lead from factory seams and use filler instead, yet in most cases with a car that still has original factory paint there is usually no problem with the lead, even after 40-60 years. So the question is why do we sometimes see paint failure over lead at some point after a repaint.

Kent White (AKA The Tin Man--master metal worker) says it is because of Intergranular Corrosion, caused by sanding the lead with Aluminum Oxide sand paper--think dissimilar metals. You are probably aware of Galvanic Corrosion when steel and aluminum are touching without a protective coating, the difference is that Galvanic Corrosion means it has a conductive solution.

Kent says, the thing to do is use Carbide or Ceramic Abrasives for lead, and of course, grinding or power sanding lead puts it in the air and we don't want to breathe that contaminated air.

The next two pictures are of a car that I have stored for over thirty years. It is a rust free car that I bought in Southern Ca from a guy not long after he had a cheap paint job put on it. It didn't show any problems around the lead seams at the time, but when I pulled it out of storage 30 years later I could see the problem. If you look closely at this factory leaded seam you can see the cross hatch sand scratch, and all the lead seams on the car are the same.

interesting, i'm always open to further my education.
Jay D.

There does seam to be some sort of Corrosion taking place evidenced by the bubbles under the paint in the Lead.

All lead is going to corrode and turn into a white powder substance over time when its not properly protected.
That one pic looks to be showing Pitting under the Paint and not just bubbles, (just an observation) And yes I see the Sand scratches which are showing and showing signs of corrosion in the scratch as well.

I would Think That if the Lead work were Tinned after final sanding similar to Tinning the metal before Lead work is done then maybe this wouldn't be happening seeing how lead wont accept Tin unless its absolutely spotless clean which would mean the lead would be free from any sanding materials after tinning it?

Not saying that's how its supposed to be done just thinking out ????
The coating of Tin from Tinning butter would be Micro thin but it would seal the lead work and ensure that there were no contaminants in-bedded in the Lead from Sanding.

I have a Car Right now with a Failed Leaded Roof seam, The Lead had cracked and the Vinyl roof failed from dry rot allowing moisture to get under the lead allowing the steel metal to rust under the Lead. I have since removed all traces of Lead and any corrosion by Blasting the area clean with Glass bead.
This Area is subject to a Lot of flex in an old Muscle car if the car is driven Hard just curious what others are doing in this area???

I Have read That filling with Just a Plastic Filler is a failure waiting to happen and Lead is the only way to go because of Body Flex, I have also read that Fiberglass fillers are the way to go???

I have also read that many are suggesting fully welding the Roof and Sail panel together fully before any filler work???

I have no problem welding the skins together I can do that its just whats gonna last as far as filler goes?

I have been kicking the idea around about getting into Lead just for this area of the Body work but at same time If Fiberglass Filler is a better long term repair I am all for using it, Not that I am against the use of Lead or anything, Its a skill I want to learn but at same time I already have a full plate right now and just wanna knock the stuff out.

I look forward to your opinions and experience

Doright wrote:...........This Area is subject to a Lot of flex in an old Muscle car if the car is driven Hard just curious what others are doing in this area???.........

You're right Doright, the sail panel area flexes the most even when making a slow turn onto an upgrade or downgrade. Auto mfgs used lead because that's all they had available at the time. These days folks use KittyHair or short strand fiberglass fillers instead of lead, and I've done the same. Can't say how long-term they work though.

There's a product called Everglass Reinforced filler that's supposed to be good for high stress areas, but I haven't used it. That would be my pick if I run into the need...

If you weld across the panel, there's a chance the metal wil tear. Lead is dangerous to work with. Maybe the best solution would be to stich-weld and use Everglass along the seam...?

Just my thoughts for what they're worth.

Been talking to a few guys at car shows with the older cars and several things have been mentioned that were new to me..... Epoxy resin instead of fiberglass resin and different fibers/fillers. Regular chip/chopped fiberglass mat, Kevlar/graphite fibers in short hairs, and ceramic micro beads were some of the ones discussed. Didn't really get any firm answer on what is working the best......

To be honest I expected more of a conversation on this topic, I know for a fact it is a problem area that more than a few have had problems with cracking out when other products are used to fill the area.
Chevman has brought up a whole new problem that I had no idea was a problem being that regular old Sand paper can be in-bedded in the Old lead when its sanded causing corrosion years later down the road. This leads me to the question of what 3M brand is a ceramic media Sand paper?

I know a lot of guys may think that a Product like Evercoats Metal to Metal may be the way to go BUT Its NOT!!!! This type of Filler Which is a Epoxy type filler that has large amounts of Aluminum in it is Very Ridged and does not flex with the body and it will definitely will crack out ruining your paint job.

I have seen in a Video by Kevin Tetz for Eastwood where he was working on a Camero Sail panel in the video. He went into some of the details about the problem area and how others have had problems there too.
They removed the Lead from the area and welded the seam solid and then made and welded in a Flush Patch over the area.
I have no idea how this worked out in the end, but he claimed it to be a good repair.
I have since went back and have tried to find the video to link it here but to no avail I cannot find the exact video.

Again I appreciate any open thoughts you may have on the subject.....

Dennis, if you want to try lead, just keep in mind lead IS dangerous, but so are paint fumes, and the same protection you use for paint also works for lead. Its just another process that has to be learned before it can be done properly, as you had to learn paint work. Everything needed is widely available, including ceramic sand paper
https://www.ebay.com/sch/i.html?_nkw=ceramic+sandpaper

Hey Chevman
Ya I know and I will end up buying into it and will be teaching myself learning it and Mastering it just like every thing else I have set out to do.
I know all to well the Temperatures required to do the work and what they can do too the metal and fear over heating and warping, Its a fine line Dance between just enough and Oops!

I have seen the videos by Bill Hines and Gene Winfield they make it look so easy.
https://www.youtube.com/watch?v=jQ_85fp1avs
https://www.youtube.com/watch?v=VMRZ61zbjpI

https://www.youtube.com/watch?v=87fuTnBS2bE

In the end I'm looking for a Replacement for the lead that will work long term.
As you know I am all for Original but at same time I like using the New technology's such as the new Panel adhesives for panel repairs, Plastic repair stuff and Today's fillers are no exception I like the New Technology's They are so much better in so many ways and worse in some. Kinda Got to know what works best and when to use what where and when and If Lead is the way to go in this area then so be it.

Plastic Filler was originally designed to replace Lead, Fillers have came a long ways since the Original Bondo in strength and durability and I find it hard to believe there is not a suitable filler that can be used in the Sail panels of the Old Muscle cars reliably without cracking out.

I watched one of the car shows last weekend and they were repairing the sail panel on a Dodge Charger. I was surprised when they used a metalized filler on it. (I assumed they would use one of the fiberglass fillers).

I agree that the All-Metal type fillers would probably crack over time. They have their place, but they do get very hard and are somewhat inflexible, and are difficult to sand.

Lead will also crack, and it's hard to get primer to stick. Not to mention the health hazards. My pick would still be a fiberglass filler in those areas that need to flex...

I can't really say lead won't crack, but I have never seen it crack on a full framed car, maybe on a unibody I don't know. I do know that lead has better adhesion, strength, and durability than any other filler. Of course a respirator and gloves are needed, and the surface has to be prepped for epoxy, as does any other substrate before paint.

Honestly, modern fillers are so good that I only use lead on seams and edges.