Body solder is a type of solder

Solder

Solder is a fusible metal alloy used to join together metal workpieces and having a melting point below that of the workpiece.Soft solder is what is most often thought of when solder or soldering are mentioned and it typically has a melting range of . It is commonly used in electronics and...

 used to smooth the surface of automobile bodies before painting. It has been largely supplanted by Bondo

Bondo (putty)

Bondo is a brand of two-part putty manufactured by 3M. Originally used mainly for automobile body repair, Bondo has been widely used by carpenters to repair wood. The Bondo brand of filler or putty is composed of a polyester resin that, when mixed with a hardener or catalyst, turns into a putty...

, but many purists and auto customizers

Car tuning

Car tuning is both an industry and a hobby, in which an automobile is modified in order to improve its performance, handling and appearance. As most vehicles leave the factory set up for average driver expectations and average conditions, tuning has become a way to personalize the characteristics...

 continue to use body solder, asserting that it bonds better to sheet metal, feels better, wears better, resists higher temperatures, and can be powder coated or otherwise chemically plated.

Body solder is available in both lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

ed and lead-free formulas from most suppliers of auto customization parts and tools. Leaded body solders usually are an alloy of lead and 2 to 10% tin

Tin

Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...

.

Body solder is melted with a blowtorch and flowed onto a car, and then shaped with a solid wood (often oak

Oak

An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

) paddle or spatula. It is then filed, not sanded, to adjust its profile.