Zinc

Zinc ( from German: Zink), also known as spelter, is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2. Zinc is the 24th most abundant element in the Earth's crust and has five stable isotopes. The most exploited zinc ore is sphalerite, a zinc sulfide. The largest exploitable deposits are found in Australia, Asia, and the United States.

Cleaning

 * Mechanical
 * Chemical

1.Diluted sulphuric acid

5 % sulphuric acid

Immerse object in solution,when it is clean rinse well with sodium bicarbonate solution(5%) and after that with water. Do not use on archaeology objects!

2.EDTA solution

EDTA 5%

pH 7

Immerse object in solution,when it is clean rinse well.

Electrolytic cleaning
 * Electrochemical

2-5% Na2CO3

stainless steel anode

current density 1A/dm2,8-10v

Object connected to negative terminal of current source must be immersed in solution, anode must be immersed before. When object is clean rinse it well.


 * Ultrasonic


 * Laser

Mechanical joining

 * Tab and slot
 * Riveting
 * Screws
 * Overlaping

Soldering

 * Hard
 * Soft

Welding

 * Electric arc
 * TIG
 * Oxyacetilene
 * Tack
 * Laser

Cementing/gluing

 * Cyanoacrylate
 * Nitrocelullose
 * Epoxy

Stabilization

 * Conversion coatings

1.Modified tannic acid treatment

1,5 gr tannic acid

1,5 gm sodium chlorate

0,2-2 gm iron(III) chloride

0,35 gm potassium titanium fluoride

0,1-0,3 gm phosphoric acid

1 lit distilled water

Immerse objects in solution(25 C temp.).Contact solution/object 60 seconds.Rinse well,dry,wax or lacquer or paint. For better paint bonding.

2.Chromating

10 gm chromic acid

0,5 gm H2SO4

1 lit water

Immerse grease and oxide free objects in solution.When yellow layer is formed stop process and rinse well. For better paint bonding. Try to avoid any contact with solution,chromic acid is carcinogenic compound!

3.Phosphating

zinc oxide 20-35 gms

phosphoric acid 20-30 gms

sodium nitrate 1,52 gms

water 1 lit

18-25 C,contact object/solution 20-40 min.

Only for better paint bonding!

Clearcoats

 * Paraloid B 72
 * Paraloid B 67
 * Paraloid B 44
 * Paraloid B 48 N
 * ORMOCER

Waxes

 * Renaissance Wax
 * Cosmolloid 80 H
 * Dinitrol 4010
 * DIY mixtures

Combinations

 * Basecoat Paraloid B 72 + topcoat Renaissance wax etc.