Dope

DOPE

From "United States Army
Aircraft Production Facts"
COMPILED AT THE REQUEST OF THE ASSISTANT SECRETARY OF WAR
By
Col. G. W. MIXTER, A. S., A. P.
and
Lieut. H. H. EMMONS, U. S. N. R. F.
Of the Bureau of Aircraft Production
—
JANUARY 1919

The function of the dope which is used on all the fabric surface of airplanes is twofold: First, it helps to stretch the cloth tight; second, it fills the fabric and creates a smooth, waterproof surface. Ordinary spar varnish is used to protect the surface created by the dope.

There are two broad classifications of dope:

Nitrate, made from cellulose nitrate and wood chemical solvents (alcohols, etc.). This produces a surface similar to a photographic film and burns rapidly.

Acetate, made from cellulose acetate and wood chemical solvents (acetone, etc.). This is slow burning.

The greatest danger in the air is fire. Nitrate dope was fairly satisfactory for training planes not subject to enemy incendiary bullets. In fighting planes acetate dope was a vital necessity.

Up to our entry into the war dope mostly nitrate was furnished by various chemical and varnish manufacturers.

PRODUCTION DEVELOPMENT.

The development of a great air program necessitated quantity production of an acetate dope. To produce the acetate dope, acetone and other chemicals had to be obtained, and a careful canvas of the situation showed that it was impossible to obtain the necessary increase, or anything like it, without developing absolutely new sources.