Bondo (putty)

Bondo is a polyester putty product originally marketed as an automotive body filler. Nowadays the brand name is used by 3M for a line of American-made products for automotive, marine and household repairs.^[1][2] The term Bondo is trademarked by 3M, but is commonly used to refer to any brand of automotive repair putty due to its popularity.^[3][4] It is also used by sculptors.^[5]

Bondo

3M's Bondo logo
Product type	Automotive body filler
Produced by	3M
Introduced	1955

History

Before the 1950s, body solder was often used to repair large imperfections prior to painting^[6] in both new cars and vehicle repair shops.^[6] Solder repairs were conducted using a flame and wooden paddles covered in tallow or motor oil, which prevented the half-molten lead from sticking.

After World War II, automotive panels became thinner and larger, with a greater susceptibility to warping, making hot solder unsuitable.^[7] The earliest 'plastic solder' can be traced to around 1940, a do-it-yourself solution to panel beating. This gave the consumer the ability to attempt reasonably priced and long lasting repairs. These early fillers were epoxy-based and one-part, drying by outgassing. Originally, the plastic fillers performed badly compared to solder, but later improvements addressed this.^[7]

Bondo, a two-part mix (resin with hardener added) of talc and plastic, was introduced in 1955.^[7] It was developed by WWII veteran and automotive repair shop owner Robert Merton Spink of Miami, Florida.^[8] Bondo was acquired by 3M in 2007.^[9]