Lead vs Bondo

I did some lead work on some pitted metal today and was pretty impressed with the result. I know it's a dying art but was interested in hearing others opinion's on the use of it. Which method do you prefer, Lead or Bondo and why? I'm interested in hearing the pros and cons of each as well as the best application to use them in. Thoughts?

I know didley squat on the matter, but I have heard that contaminants come out of the lead, which have to be thoroughly cleaned away to prevent paint issues later. Hopefully an expert can elaborate on it.

You are good... it is not easy to get lead to stick to steel and be somewhat level.

My choice on beat up metal or welds is neither. I use a first fill of epoxy. JB weld or PC7. It sticks very well to steel... much better than bondo and is waterproof. I use bondo for final smoothing.

Here's some discussion I found on the WWW. BTW, it's called lead, but it's actually solder.


Question
Would you elaborate about preparation regarding lead body repairs?
Any good books on the subject that you would recommend?



Answer
Preparation is pretty straight forward. All galvanized coatings must be completely ground off, all paint must be removed, all rust completely sand blasted out. Lead actually likes sand blasted steel. I highly suggest having some heat sinking putty around the spot. Play-Doh will work, but dries out quickly.

First, you need to tin the area with acid core solder. Go beyond the area you intend to lead. Then, you apply lead. You work and smooth lead with heat and wooden lead paddles. The paddles are occasionally dipped in beeswax to keep lead from sticking, and to cool the paddles. The wax comes in a little tub, it's hard like a candle. It must be melted with the torch, but just enough to sorta dip the paddle in.

Lead is a joy to work with. Unlike Bondo, it can be reworked once it's hard. Just heat it up and paddle it out. I like to work it with a body file, it cuts fast, and body files were made for working lead. You can also sand it conventionally with sandpaper, and should final sand with some 180 on a DA if you do all the work with a metal file.

Once you are done, the area must be wet sanded with 320 wet or dry paper to remove any acid from the tinning process. Hope this makes things a little clearer for you. I don't know of any good books on the subject, sorry. I was taught by an old pro, and he was taught by his uncles.

Lead work is an art I learned when working on expensive imports in the 60s but Bondo is easier and cheaper. Now days the metal is thinner and lead doesn't work to well. The heat necessary to lead is too much for the thin metal and makes it warp.

Today was actually the first day I used it. A guy I work with use to own a restoration shop many years ago and was kind enough to teach me how to do it. It was basically the same method as posted above.

To work it so quickly is pretty convenient as is the ability to reshape it, be it to move it around or to even hammer and dolly it after application.

When done well it's almost a shame to cover it up since clean metal work is so rare anymore. I guess that's the difference between running a business and doing it as a hobby though.

I'll challenge that. Car bodies from the muscle car era until the present day are made of 0.032" steel. I guess pre-war cars were a little thicker. I do believe some body parts of older Japanese cars may have been a little thinner.

I was a mill sales rep for cold rolled steel sheet in coil. "Automotive gauge" steel is 0.032" thick, and the auto industry is the 800-pound gorilla in the cold rolled market. For this reason just about every cold rolled mill in the world is optimized to roll "oh thirty two". .032 is "base price" or the cheapest thickness to produce. That's why clothes washers, water heaters, refrigerators, filing cabinets, etc. are mostly .032.

My '69 Barracuda is .032 in the fenders, doors, wheel tubs, floor pan, and all the rest of the body panels. So is my '05 GTO from Australia. If I buy a new Challenger it will be .032 too.

Whenever I have 'miked' steel on my cars, it usually was about .035 or so due to paint. Take off the paint, and it's .032.

I cringe when people want to talk about gauge numbers for steel thicknesses. Gauge numbers were abandoned by mills and customers early in the industrial revolution. Every steel mill in the world rolls to decimal inches or millimeters, not to any gauge number. And steel mill customers order and buy in decimal inches or millimeters, not in any gauge number.

I have dealt with some 90's Japanese cars and can confirm that at least as far as Mitsubishi goes some of the sheet metal is thinner. The stuff I was in contact with in the shop was like tinfoil.

There is a rotted '88 Shelby Daytona sitting in the yard, I'll have to take a mic to it in a few spots and check. I'm of the opinion too that at least since the 80's the sheet metal on cars is thinner.

When the windshield company put new glass in my '87 CSX he dented the roof with his elbow! Had to get the dent wizard out to fix it. I have never seen a "classic" mopar dent that easy.

BTW- I have done some lead work too filling pin holes that were in the donor tunnel ram hood for my GTX. It came out real nice and would use this method again.

Any truth to the rumor that using lead will give off fumes that can be harmful to your health and that protection is advised?

Fumes, dust that can be ingested through lungs or eating a sandwich, it's all true. Lead isn't good for you.

Lead is especially harmful to children, born and unborn. It is carried in from your garage in a number of ways. So if you value your children or grandchildren.....................

How much lead will actually harm an adult is another question. We'll have to get an industrial hygienist's opinion on that.

R.

FYI this is correct, as far as an 87 GLHS goes. I'll check a 75 Dart tomorrow.

Lead is readily absorbed through the skin as well so gloves are a must. If you're going to sand it (and you will) a good respirator is also a must. As dogdays so noted, lead dust can and will saturate your clothes so be mindful of what you drag into the house with you. Take precautions and enjoy the spectacle of Pb.

i never would have thought of that!

I don't think it would stay flexable enough.

You can get materials from Eastwood that are "lead free".
I had to lead the seams where the roof meets the quarter panel. I didn't how well the lead free stuff worked so I opted for the "lead" and made sure I had plenty of ventilation.
You don't want to go thick with bondo.

Any substance can cause issues with health, temporarily, or permanently, so use commonsense, as to some of the worrywarts comments posted here on lead, unless your going to be opening up a lead smelting shop, I wouldn't be concerned over the SHORT term usage you may intend

Then again you are in California, so EVERYTHING has a health warning label on it

Correct assessment. Only place such a label is missing is where it is most needed.

Stamped on the foreheads of our Governor and other such assorted nutsos of our purported illustrious Governmental 'Officials'.

This unthinking, aggressively ignorant attitude is what turns many off to the car culture.

There are many things that are "harmful" that I don't worry about. But lead is on the list of things I worry about.

AS I SAID, I don't know the level at which it poses a health risk to adults. But I do know that lead is transported when Dad walks in the door from the garage, probably airborne lead as well.

It is a fact that lead is harmful to children. Their brains are still developing. It doesn't take industrial amounts of lead for that to happen. So stop speaking from ignorance.

R.

It takes a lot more than you would bring in on your shoes from a simple lead repair. You really need to take your own advise and stop speaking from ignorance and fear mongering.

If you had bothered to read or perhaps you have already forgotten, it was I that first suggested possible dangers from lead in this thread.

Your extremist attitude is exactly what both Dayclona and I were suggesting is the state of mind in the state of Calyforunua enabled on by voters who for the most part don't have the scientific wit to understand what is the phenomenon that causes the 24 hour cycle of night and day.

Yet they and those for whom they vote for are for banning plastic bags, nuclear power, dams and all fossil fuels. No matter the costs, because as Bernie suggests, someone else will pay for it. You must live here to understand.

I suggest you lighten up and attempt to bring a little humor into your life. Just as Dayclona was attempting with his posting. Apparently he struck a nerve instead.

jb weld is not flexible it can crack or pop out if used on the body of a car that has a lot of flex. not the best choice for bodywork for sure.

I am not against filler or lead, but I prefer to cut out where the panels meet and fabricate a sheet metal filler, then but weld the panels so there is no seam at all. Then metal finish.

yolo

one tip i can pass on is
before you apply the flux or tin the area,
use bronze wool, not steel wool to clean up the area you are working on.
you can find it at a marine supply place
the reason is
steel wool will leave small particles into the metal that will cause rust under and around the lead
even after it is epoxy primed.
the more you play with lead the easier it gets.

I did it this way.... very little bondo will be left here...

Isn't there an aluminum filler called All-Metal? Anybody use this?

Over rated/priced bondo, has it's uses, just not were joints are best leaded

Well, the thing I don't like about bondo or other plastic body fillers, is that it is porous, & there is solvent pop after time. I've seen it on SO many filler jobs that had been applied years before. I've never used the metal fillers, but might try the stuff next time I need filler.

i have yet to see a filler that doesn't shrink or become porous
like you mention over time.
when they invent one, i might consider using it for that application.

that said,
for a vinyl roof car, i would use it on the roof
a painted roof car.. no way jose!

I melted the lead and removed my roof off of my 64 Savoy sedan about four months ago and found no rust or any problem with the joint. Pretty good for 52 years. Lead is going back on those seams, and I'll reuse the same lead (got a few cars I can get more from)

anyone ever use 50/50 lead solder for this type of repair ?

Standard autobody lead is 60/40, Tin/lead, with 50/50 the tin content is lower which will make it "pastey" to work with properly, the higher Tin content is to help promote adhesion and flow, the "lead free" solder "kits" on the market are mostly Tin, which is more expensive and also has a higher eutectic (melting) point of 450 degrees vs 360 degrees for 60/40

Learned lead work from a old timer that only metal finished or leaded. He was the best body man I ever met. He could straighten anything but never worked on anything newer than the 50's. Bondo is easier but lead is more traditional and should last longer. Last newer car I tried lead on was a 79 Capri. Touched it with a torch and if warped all over. I've used 60/40 70/30 both. Could tell much difference between the two.