Lead on top of lead

[Jsand160]

Several years ago I replaced the roof skin on my challenger I was restoring. Lead was used in the seam from the roof skin to the rear quarter. After removing all old material and roof skin, I replaced the roof skin and leaded the seam again. I did not get enough lead into the seams at the time and filled in the rest with body filler. I put a vinyl top on and it has been fine ever since. Fast forward, I am repainting my car and removing the vinyl top and I want to make sure I have the seams properly fiinished. If I clean out the bondo and clean up the leaded areas, can I reapply more lead on top of the other lead, if it is the same 30/70 blend? I’m guessing I would have to tin the metal around the leaded areas that is metal.

[Len]

Several years ago I replaced the roof skin on my challenger I was restoring. Lead was used in the seam from the roof skin to the rear quarter. After removing all old material and roof skin, I replaced the roof skin and leaded the seam again. I did not get enough lead into the seams at the time and filled in the rest with body filler. I put a vinyl top on and it has been fine ever since. Fast forward, I am repainting my car and removing the vinyl top and I want to make sure I have the seams properly fiinished. If I clean out the bondo and clean up the leaded areas, can I reapply more lead on top of the other lead, if it is the same 30/70 blend? I’m guessing I would have to tin the metal around the leaded areas that is metal.

I can't give you lead advice but I have to ask why don't you just use a good quality bondo-type filler?

[Jsand160]

I can't give you lead advice but I have to ask why don't you just use a good quality bondo-type filler?

I had body filler to finish it before, but it was awfully thick. Well over a 1/4” thick. Probably closer to 1/2”. I would like to use the lead as close to flush as possible and finish with filler.

[Len]

I had body filler to finish it before, but it was awfully thick. Well over a 1/4” thick. Probably closer to 1/2”. I would like to use the lead as close to flush as possible and finish with filler.

If you need to level the surface won't you need the same thickness of lead as you would body filler? A decent body filler will work better than lead as long as you don't get moisture coming through the seam.

[Phil V]

I'm proficient at using lead as a filler. I worked in one shop back in the mid 70's that required us to use lead and no "bondo" type fillers. The best advice I can give anyone about working with lead is for 99% of situations the modern polyester fillers (bondo, generic term) are much better all the way around compared to using lead as a filler. In short --- "if it ain't broke then don't fix it". In other words don't remove the existing lead if there are no blistering around the edges and no rust around the edges. If your car's sail panel leaded area has been problem free for years then it's going to remain that way for a LONG time (quite possibly many decades).

Working with lead has some inherent serious drawbacks that you don't face with modern body fillers (bondo, generic term). As you stated you have to tin the metal in order to get the lead to stick. You have to use a tinning acid in order to tin that metal. One tiny drop of that acid can create a rust problem that will exponentially get worse over time. When you work lead sometimes the lead in it's workable state will get folded over other lead. If there is a drop of that tinning acid gets trapped in one of those overlaps then you WILL have a rust problem if that acid comes in contact with steel. Working with lead is a pain in the ass and modern fillers are much better all the way around.

If the existing filler over the lead on your sail panel doesn't have any blistering or cracking then I wouldn't grind that out to replace it either. You really aren't going to gain anything by adding more lead to lessen the thickness of the polyester filler over it. A half inch or even a little more is not a deal breaker in a sail panel area. It should be problem free for decades. I have worked on special interest cars, hot rods etc where filler was applied by a previous bodyman at least an inch and a half thick. It was that way for many years in some cases with no problems of cracking etc. Don't get me wrong, I'm not recommending applying filler an inch and a half thick. Just relaying what some my personal experiences have been of previous bodymen applying it that thick. The only time filler has problems is from the body flexing like quarter panels on a full on drag race car where I've seen metal panels just buckle from the torque twisting the body of the car. Filler in a normal car will only crack if it sustains damage from an impact like getting hit by another car etc. Or if for some reason moisture is introduced from the back side (like rust holes forming in the metal that filler is attached to). Then the filler will bubble and crack as the rust expands.

So, to me your sail panel issues are a non issue.

Going off on a tangent here -- In very rare instances lead is actually better than "bondo". Like working on a damaged door edge or collision damaged front edge of a quarter panel where it meets the door. Particularly where minor impacts occur that could knock "bondo" loose or make it crack. In most cases like that the lead filler will not crack unless it's hit really hard. I still have my lead working tools and on a rare occasion I will do some lead work just to prove to myself I can still do it. Other than that I exclusively used polyester filler/"bondo".

Evercoat makes some great premium polyester fillers like Rage Gold and Rage Extreme.