The Forth Bridge/Painting
Painting.
All plates, bars, angles, and other parts belonging to the superstructure, received as soon as they had passed through the shops or yards a thorough scraping with steel scrapers and steel wire brushes, and afterwards a coat of boiled linseed oil applied as hot as possible. As soon after erection upon the structure as could conveniently be done, and in many cases also before they were put up, they received a coat of red lead paint, and subsequently a second coat of red lead. The paint finally decided upon for the bridge is an oxide of iron paint, of which two coats are applied over the two coats of red lead already laid. The first is called a priming coat of dark chocolate brown ; the last is a finishing coat of a bright Indian or Persian red, which, however, darkens considerably in a short time. Four different kinds of paint are used, all, however, of the same composition, if of different makers.
At Fife: Craig and Rose's.
At Inchgarvie: Galley's Torbay.
At Queensferry : Carson's.
For central girders: Wolston's Torbay.
The above are for outside painting only, the inside of the tubular members receiving one coat of red and two coats of white lead paint. It is calculated that inside and out, the amount of surface to be painted is equal to 145 acres.