Matt Dip For Brass, Etc

Dissolve 6 oz. clean sheet zinc in 1 gal. hot nitric acid, then pour in sulphuric acid slowly until dip looks white, then heat to 1600 F. and test; if too coarse add sulphuric acid. Stir with glass rod; never use wood, and don't put hydrochloric acid in it.

Removing Copper Oxide From Brass After Brazing

Old bright dip heated to 1500 F., then add 2 qts. of sulphuric acid for every gallon of bright dip.

To Copper Wire Nails or Iron Screws:-

To Boil Brass Articles White

Put 8 oz. pure tin shavings and 6 oz. cream of tartar into a boiling pot with 1 qt. of water. Make sufficient to cover the work and boil.

Various S/iades of Brown on Brass, etc.:-See p. 154.

Various Shades of Brown, including Brilliant Shades of Blue:-

To be used hot and each chemical to be dissolved separately. Green Bronze:-

Brush the work over with this and let it dry. Repeat until the right colour is obtained.

Steel Colour on Brass:-

Immerse, wash off, scour with sand, and repeat until a good colour is obtained, then brush up with blacklead.

The procedure for the above cases is similar in nearly all. The work must be thoroughly cleaned and dipped bright and then immersed in above solutions. To obtain the best results a little practice is essential. Surface colours or patinas may be obtained-By chemicals as above. „ heating.

,, oxidizing or atmospheric influence. ,, alkalis.

„ electro deposition. ,, dipping in molten metals. ,, varnishing or lacquering.

„ rolling, that is, soldering a thin piece of metal on to a thick base and then rolling all out together; examples: Sheffield plate, rolled gold.