Marvin Pipkin

Marvin Pipkin (Nov 18, 1889 - Jan 7, 1977) is best known as the inventor of the inside-frost process of bulbs for incandescent lamps, which was developed in 1925, as well as the improved process developed in 1947, which consisted of an application of silica to the inside of a bulb. This new process was called: "Q-coat." The picture to the left shows Pipkin holding up a sample of each of the developments. He also held several patents on photoflash lamps.

Marvin Pipkin was born in the Christina area south of Lakeland, FL and was one who had a pronounced Dixie accent. He was the son of David M. and Catherine (Moore) Pipkin. His father was a farmer and grove owner and planted the first citrus trees in the Medulla and Christina areas.

Pipkin received his primary education in Lakeland and his secondary education at the Summerlin Institute in Barlow. One of his Summerlin classmates remembered Marvin as a shy, gawky, sandy-haired, freckle-faced boy who knew more chemistry than all the rest of the class put together.

After graduation from high school Pipkin joined a prospecting firm for a year and then worked, for a short time, at the International Agricultural Corp., later known as the International Mineral and Chemical Corp. of Barlow.

Pipkin attended Alabama Polytechnic Institute (API) and received a Bachelor of Science degree in Chemical Engineering from that institution in 1913. After working in fertilizer and phosphate laboratories in Barlow for a year he returned to API and, in 1915, earned a master's degree.

On Nov 5, 1917 Pipkin enlisted in the Army in Jacksonville. Because the Germans had introduced poisonous gas into warfare there was a need for persons with a chemical background to work on gas masks. Pipkin entered the Gas Defense Department as a private and was posted to the laboratories at Nela Park in Cleveland.

One of the first discoveries that emerged from the Nela laboratory was due to Pipkin. He found that the activity of charcoal for phosgene (a highly poisonous liquid) could be significantly increased by the introduction of hydrated manganese dioxide into it. Subsequent findings and understanding led to accurate determinations of the effect of water on the absorption of gases by charcoal. Pipkin attained the rank of Master engineer, senior grade. After his service he remained at Nela to work in the Lamp Development Laboratory.

The glare from incandescent lamps was something many people wanted to reduce. A common technique used on early incandescent lamps consisted of an outside acid etch on the bulb. However, such a process led to remarkably reduced strength of the bulb. In 1925 Pipkin developed an etch on the inside of the bulb that did not weaken the glass (U.S. Patent No. 1,687,510). It was a process that was standard for about 30 years. Work performed in 1947 resulted in an improvement in the coating of the bulb. That improvement was achieved by means of an inside coating of silica on the bulb (U.S. Patent No. 2,545,896).

Marvin Pipkin retired from Nela Park in 1954 and resettled in his home town of Lakeland, FL. He had married Kathryn Patricia Enright (d 1957) on Jul 21, 1919 and they had three children. Pipkin passed away at the Lakeland General Hospital in 1977 after a lengthy bout with cancer.