Tungsten Paints

Themineral colours from tungsten are obtained by decomposing soluble tungstates by means of salts of the metals yielding insoluble phosphates. The tungstate of nickel produces a light green, tungstate of chromium a dark grey, tungstate of cobalt a violet or indigo blue, and tungstate of barium a bright white colour. Tungstic acid alone gives a fine light greenish-yellow. All these colours may be employed for water- or oil-colour paints; the last is a really desirable and probably quite unchangeable colour.

Window Paint

Mix with white lead, boiled oil or varnish, and a small quantity of driers (no turps, which hardens for the time, being a volatile oil, and therefore objectionable in this case); paint this over the glass thinly, and stipple it. If you have not a proper brush, make a large pledget of cotton wool or tow, cover it with a clean bit of linen rag, and quickly dab it over the paint.

Zinc Paint

The difficulty of making oil colours adhere to zinc is well known.

Some Time Since

Prof. Bottger published a process which consists in applying with a hard brush a mordant composed of 1 part copper chloride, 1 copper nitrate, 1 sal-ammoniac, and 64 water, to which is added afterwards 1 hydrochloric acid. The zinc immediately becomes intensely black, which changes in drying (12 to 24 hours) to a dirty whitish grey, on which oil colours may be laid, and to which they will adhere firmly.

Painting

The composition of paints should be governed- - (1) by the nature of the material to be painted: thus the paints respectively best adapted for wood and iron differ considerably; (2) by the kind of surface to be covered - a porous surface requires more oil than one that is impervious; (3) by the nature and appearance of the work to be done: delicate tints require colourless oil, a flatted surface must be painted without oil (which gives gloss to a shining surface), paint for surfaces intended to be varnished must contain a minimum of oil; (4) by the climate and the degree of exposure to which the work will be subjected: for outside work, boiled oil is used, because it weathers better than raw oil, turps is avoided as much as possible, because it evaporates and does not last; if, however, the work is to be exposed to the sun, turps is necessary to prevent the paint from blistering; (5) the skill of the painter affects the composition; a good workman can lay on even coats with a smaller quantity of oil and turps than one who is unskilful; extra turps, especially, are often added to save labour; (6) the quality of the materials makes an important difference in the proportions used: thus more oil and turps will combine with pure than with impure white lead; thick oil must be used in greater quantity than thin; when paint is purchased ready ground in oil, a soft paste will require less turps and oil for thinning than a thick; (7) the different coats of paint vary in their composition: the first coat laid on to new work requires a good deal of oil to soak into the material; on old work, the first coat requires turpentine to make it adhere; the intermediate coats contain a proportion of turpentine to make them work smoothly; and to the final coats the colouring materials are added, the remainder of the ingredients being varied according as the surface is to be glossy or flat.

The exact proportions of ingredients best to be used in mixing paints vary according to their quality, the nature of the work required, the climate, and other considerations. The composition of paint for different coats also varies considerably. The proportions given in the following table must only be taken as .an approximate guide when the materials are of good quality: -

Table Showing The Composition Of The Different Coats Of White Paint, And The Quantities Required To Cover 100 Yd. Of Newly-Worked Pine

Red-lead.

White-lead.

Raw

Linseed-oil.

Boiled Linseed-oil.

Turpentine.

Driers.

Remarks.

Inside work, 4 coats not flatted.

lb.

lb.

pt.

lb.

Priming

1/2

16

6

___

-

1/4

Sometimes more red-lead is used and less drier.

2nd coat ..

*

15

3 1/2

__

1 1/2

1/4

3rd coat

-

13

2 1/2

-

1 1/2

1/4

* Sometimes just enough red-lead is used to give a flesh-coloured tint

4th coat

-

13

2 1/2

-

1 1/2

1/4

Inside work, 4 coats and flatting.

Priming

1 1/2

16

6

-

1/2

1-8

2nd coat

12

4

-

1 1/2

1-10

3rd coat

-

12

4

-

0

1-10

4th coat

__

12

4

___

0

1-10

Flatting .. ..

-

9

0

-

3 1/2

1-10

Outside work, 4 coats not flatted.

When the finished colour is not to be pure white, it is better to have nearly all the oil boiled oil. All boiled oil does not work well. For pure white, a larger proportion of raw oil is necessary, because boiled oil is too dark.

Priming

2

18 1/2

2

2

-

1-8

2nd coat

__

15

2

2

1/2

1-10

3rd coat

-

15

2

2

1/2

1-10

4th coat

-

15

3

2 1/2

0

1-10

For every 100 sq. yd., besides the materials enumerated in the foregoing, 2 1/2 lb. white-lead and 5 lb. putty will be required for stopping. The area which a given quantity of paint will cover depends upon the nature of the surface to which it is applied, the proportion of the ingredients, and the state of the weather. When the work is required to dry quickly, more turpentine is added to all the coats. In repainting old work, two coats are generally required, the old paint being considered as priming. Sometimes another coat may be deemed necessary. For outside old work exposed to the sun, both coats should contain 1 pint turpentine and 4 pints boiled oil, the remaining ingredients being as stated in the foregoing table. The extra-turpentine is used to prevent blister-ing. In cold weather, more turpentine should be used to make the paint flow freely.

Surface painting is measured by the superficial yd., girting every part of the work covered, always making allowance for the deep cuttings in mouldings, carved work, railings or other work that is difficult to get at. Where work is very high, and scaffolding or ladders have to be employed, allowances must be made. The following rules are generally adopted in America in the measurement of work: - Surfaces under 6 in. in width or girt are called 6 in.; from 6 to 12 in., 12 in.; over 12 in., measured superficial. Openings are deducted, but all jambs, reveals, or casings are measured girt. Sashes are measured solid if more than two lights. Doors, shutters and paneling are measured by the girt, running the tape in all quirks, angles or corners. Sash doors measure solid. Glazing in both windows and doors is always extra. The tape should be run close in over the battens, on batten doors, and if the stuff is beaded, add 1 in. in width for each bead. Venetian blinds are measured double. Dentels, brackets, medallions, ornamented iron work, balusters, lattice work, palings, or turned work, should all be measured double. Changing colours on base boards, panels, cornices, or other work, one fourth extra measurement should be allowed for each tint.