Classic/Antique Car Repair: Metal repair, lead metal, neex

Question
Hello Dick
I am taking a course on Industrial Hygiene, and one of our assignment is the control of lead in a antique bodyshop. I would need to know where and how is lead metal used in repairing an antique car. What form does the lead come in, what process is used to work with it.
It would be gratly appreciated.
By the way, I have to hand in the assignment by tuesday neex week.
Thank you for your time.
Luc

Answer
One of the things I learned the hard way in school was to read carefully  all the material I was given.   If you had done that, you would have seen in my info on this site that I am here to answer questions about mechanical problems, and that I am not now nor have I ever been a body and paint repairman!

However, since you are on deadline, and waited until almost he last minute to ask, and even though it is AllExperts policy not to help with homework,  I can tell you that lead was used on antique cars in both the original construction and during repairs, to fill low spots on body panels, and to hide seams where two metal parts were welded together.  The lead comes in plain pure lead metal bars, about 1 foot long by 1 inch square.  It is used by melting it with a flame to a state of eutectic - which means it is somewhere between solid and liquid - sort of a paste.  This happens around 800F.   The lead paste is pressed into the metal to be mended, and smoothed with a wooden paddle which is dipped into beeswax until the desired contour is achieved.  Then the lead is allowed to cool and finally given a final sculpting with files.  Before the lead is applied to the metal, the metal is treated with a powerful acid flux, to clean all impurities off the metal.  After the repair, the area worked on has to be treated with a neutralizing base to remove all traces of the acid, to prevent corrosion of the metal.  During the heating process, fumes of lead and acid are given off, which the worker inhales.  The workers often develop rather strange personalities.

This technique of body repair has been obsolete for over 50 years now, except in a few shops where the car owner and the shop operator agree that the repair must be done using the antique methods, for reasons of accurate restoration.

Go forth and study now!

Dick