Rusting

“ In this process the varnish will enter the pores of the metal sufficiently to prevent rusting, but will not show on the surface after having been carefully rubbed off as directed. A polished surface like that of a finished gun barrel, is not much liable to rust, and, indeed, seldom begins to rust, the rust starting in the pores of the metal and finally working outward. ”

“ It seems to be a curious fact that the more quickly a product or an article is fashioned by man, the more quickly it tends to return again to its original oxidized condition. Some manufacturers of steel, however, through an understanding of the causes of rust, have progressed in the manufacture of slow rusting materials, either by the elimination, or by the proper distribution of impurities. ”

“ Because iron rust is an oxide of iron, having an excess of oxygen. Spread on rusty iron, it penetrates the rust, absorbs its excess of oxygen and dries with the remaining neutral oxide held fast in its body. This is my theory; whether correct or not, numerous tests have proved to me that a coat of linseed oil will stop the rusting of iron if applied under proper conditions. When rust is thick or scaling there is no safety short of taking it off. Iron rust is more or less hydrated; to free it from moisture, give it the flame of the gasoline paint burner. ”

“ The decaying of wood and the rusting of metal are due to the action of air and moisture. When wood and metal are surrounded with a covering which neither air nor moisture can penetrate, decay [254] and rust are prevented. Paint affords such a protective covering. The main constituent of paint is a compound of white lead or other metallic substance; this is mixed with linseed oil or its equivalent in order that it may be spread over wood and metal in a thin, even coating. After the mixture has been applied, it hardens and forms a tough skin fairly impervious to weathering. ”

“ the wind has blown away the white ashes of his camp-fires; but the empty sardine box lies rusting over the face of the Western earth. ”

“ In one place objects are found covered with a slight layer of rust only, in another with a thicker layer, in another there remains but a small core of metal, or even none at all, or the layer of rust may be intermingled with particles of earth or clay. The rust may be uniform in colour and hardness in one case, and in another soft areas, generally light in colour, may alternate with darker, harder patches, while frequently the harder layer is found below the lighter and softer, etc.—conditions which depend on the occurrence of the various iron compounds. ”

“ A coating of rust, formed of flakes within flakes, incloses it; and this thickens year by year, until, perhaps, it reaches a stage at which its exterior loses as 49much by rain and wind as its interior gains by further oxidation of the iron. Most mineral masses—pebbles, boulders, rocks—if they show any effect of the environment at all, show it only by that disintegration of surface which follows the freezing of absorbed water: an effect which, though mechanical rather than chemical, equally illustrates the general truth. ”

“ Of all the woods in this country, this is without exception the most durable, and withstands putrefaction longer than any other; it is therefore employed in all such cases where it is most liable to rot, especially for all kinds of posts which are to be put into the ground. Some people say, that if an iron be put into the ground along with a pole of cedar, the iron would be half corroded by rust in the same time that the wood would be rotten. ”

“ PROTECTION BY RUST. Rust is usually associated with decay. Professor Faraday, however, observes that, in some cases, it is curious to see how tin, a metal having a slight attraction for oxygen, protects other metals from oxidation or rust. In Canada, tin-plate is used for the roofs of houses, and you are dazzled by the lustre of the setting sun upon the roofs; whilst there, although it is exposed to the atmosphere year after year, it does not decay, because the superficial coat of oxide protects the tin and iron beneath. ”

“ For not only Bread, Flesh, Fruit, and such other things as are used for daily food, do grow mouldy much sooner in the moist places, and so corrupt, but also even Metals themselves too, as Iron, Copper, Tin, and the like, even these cannot shun the corruption of the Air, but are laid over with Rust, which (in a drier air) they do not so easily contract.
By all these circumstances it is so clearly evidenced, that superfluous moisture is to all things alwaies hurtful, and gives an inlet unto Corruption, that I think there is no body that will dare to say any thing to the contrary. ”

“ When rusty, iron no longer has the properties that make it so useful to us; it is a kind of red or yellow earth, in which, without looking attentively, it would be impossible to suspect a metal.”
“I can well believe it,” said Jules. “For my part, I should never have taken rust for iron with which air and moisture had become incorporated.”
“Many other metals rust like iron; that is to say, they are converted into earthy matter by contact with damp air. The color of rust varies according to the metal. Iron rust is yellow or red, that of copper is green, lead and zinc white.” ”

“ The rust produced on the surface of Iron is a sort of calx of Iron made by way of dissolution. The moisture of the air acts upon the metal, dissolves it, and robs it of some of its phlogiston. This rust is called in Medicine Crocus Martis Aperiens; because it is thought that the saline parts, by means whereof the humidity dissolves the Iron, remain united with the metal after its dissolution, and give it an aperitive virtue. ”

“ Use the best tools; never lay them down but in their proper place; and always clean them before putting them away. Keep all the wood-work of tools well painted, and the iron and steel in a condition, by the application of oil and otherwise, to prevent rust. ”

“ Among the blue rags turn up some blocks tinged with a stain of yellow or rust colour, which seem to be nearly as lasting as the blue; and every now and then balls of a friable substance, like rust of iron, called rust balls. ”

“ Drying. When the steeping is finished the limestone is taken out to be dried. Small objects may be placed upon a glass ring, wooden tripod or some such appliance, which admits air on all sides, and may thus be dried by the air only. A piece of paper laid loosely over them will protect them from dust. In winter a hot stove, or similar source of heat, affords a satisfactory method of drying, but wet stones must not of course be placed directly upon the hot iron stove plate [68] lest spots of rust should be produced upon the stone. ”

“ If, however, the cause, namely, exposure to moist air, continues, more and more of the iron becomes rusted, until all which is exposed is converted into a red powder, when one of the conditions of the production of rust, namely, the presence of unoxidized iron, has ceased, and the effect cannot any longer be produced. ”

“ It rains almost invariably once in every twenty-four hours; but oftener five or six times. The dampness is phenomenal. All mirrors become patchy; linen moulds in one day; leather turns while woollen goods feel as if saturated with moisture; new brass becomes green; steel crumbles into red powder; wood-work rots with astonishing rapidity ”

“ Bubbles of hydrogen will immediately rise and the rust will begin to separate. In freshly prepared acid objects which are not very rusty will be freed from rust after four to six hours, those covered with a deeper layer of rust in about twelve hours, but several days, or even weeks, may be necessary. ”

“ In this case, that same part of the air has joined up to part of 54 the iron tacks to form that red powder which we call rust.”
Questions and Exercises. 1. How is rust formed? 2. Explain why things which are made of iron should be painted. 3. A grate full of coals burns away and only a small quantity of ash is left in the grate. What has become of the coals?
55 VIII.—THE FIRE-BALLOON.
One day Uncle George made the children a fire-balloon. ”

“ There is a cause which affects all wood most materially, which is the application of paint, tar, or pitch before the wood has been thoroughly dried. The nature of these bodies prevents all evaporation, and confines the internal moisture, which is the cause of sudden decay. Both oak and fir posts may be brought into a pre-mature state of decay, by their having been painted prior to a due evaporation of their moisture, and painting affords no protection to timber against dry rot. ”

“ They are visited by periodical rains, which are often powerful, and in general the humidity of the atmosphere is very great, causing iron and other metals that are easily oxydated, to be covered with rust. ”

“ Beneath the black sand which usually covers this ground there frequently occurs a very hard iron rust, or thin stratum{98} of oxide of iron, which prevents drainage of the soil, with a blue sandy clay underlying. ”

“ The varnish is to be applied by means of a sponge; and articles varnished in this manner will retain their metallic brilliancy, and never contract any spots of rust. It may be applied to copper, and to the preservation of philosophical instruments; which, by being brought into contact with water, are liable to lose their splendor, and become tarnished.
59. To keep Arms and polished Metal from Rust.—Dissolve one ounce of camphor in two pounds of hog's lard, observing to take off the scum; then mix as much black lead as will give the mixture an iron color. ”

“ The soil was altogether chalk, dug from the side of the hill below, of which the whole barrow is made. Six weeks after, I came to rescue a curiosity which they took up there, an iron chain, as they called it, which I bought of John Fowler, one of the workmen: it was the bridle buried with the monarch, being only a solid body of rust. I immersed it in a limner's drying cloth, and dried it carefully, keeping it ever since very dry. It is now as fair and entire as when the workmen took it up. ”

“ When wanted, brush hard with a stiff brush; there will be a beautiful surface. Anything pitted with rust may as well be thrown away. A merely rusty surface must be greased with clear fat, left standing two days, wiped, washed in clear, very hot water, and greased again. Three greasings should bring it into condition for polishing. Wipe dry, coat with oil, shake on lime, and brush off after twenty-four hours. Any alkali without grease predisposes iron to rust. Eschew soap and soda in cleaning it. Use gasolene or turpentine or even kerosene. A cloth wet in 126either will take off smut. ”

“ It is far lighter than tin, has the colour and lustre of silver, and never tarnishes, the only rust produced by oxidation of its surface being a white loose powder, which can be brushed or shaken off without difficulty. ”

“ Thus the agents which by their combination produced red precipitate, namely, the mercury and the gas, reappear as effects resulting from that precipitate when acted upon by heat. So, if we decompose water by means of iron filings, we produce two effects, rust and hydrogen. Now rust is already known, by experiments upon the component substances, to be an effect of the union of iron and oxygen: the iron we ourselves supplied, but the oxygen must have been produced from the water. ”

“ The prosperity of modern states is dependent on the amount of iron rust which they possess and utilize. England, United States, Germany, all nations are competing to see which can dig the most iron rust out of the ground and make out of it railroads, bridges, buildings, machinery, battleships and such other tools and toys and then let them relapse into rust again. ”

“ Wood, bitumen, resins, coals, fat and oil, by expression, wax, and suet, are substances proceeding immediately from animals and vegetables. Turf, fossil, coal, amber, liquid, or concrete bitumens, are the productions of their mixture, and their decom [58] position, whose ulterior waste forms sulphurs, and the combustible parts of iron, tin, pyrites, and every inflammable mineral. I know, that this last assertion will be rejected by those who have studied nature only by the mode of chemistry ”

“ Turnbull, for an improvement in the common process of bleaching cotton, or linen pieces: Take any kind of earth which is easily mixable with water, such as clay, marl, or Fuller's earth, or if that cannot be had, any kind of soft mud or the like, which is put into a boiler to evaporate the moisture, dried, again mixed with water, and passed through fine sieves. This powder is then mixed with quick-lime, which is slacked in the earthy mass, and forms the materials for the several buckings which the cloth is to undergo. ”

“ Coal and burnt wood produce iron dross, which includes the most fixed parts of iron that vegetables contain; it is this fixed iron which forms the sand here spoken of, when the dross is decomposed by the action of the air, sun, and rain, for then these pure iron particles, which are not subject to rust, nor to any other kind of alteration, suffer themselves to be carried away by the water, and penetrate with it some feet deep into the earth. ”

“ But I must return, and tell my readers, in a few words, the chemical history of mortar. If limestone be burnt, or rather roasted, in a kiln, the carbonic acid is given off—as you may discover by your own nose; as many a poor tramp has discovered too late, when, on a cold winter night, he has lain down by the side of the burning kiln to keep himself warm, and woke in the other world, stifled to death by the poisonous fumes. ”

“ To Remove Rust From Nickel.—Smear the rusted parts well with grease (ordinary animal fat will do) , and allow the article to stand several days. If the rust is not thick the grease and rust may be rubbed off with a cloth dipped in ammonia. If the rust is very deep, apply a diluted solution of hydrochloric acid, taking care that the acid does not touch the metal, and the rust may be easily rubbed off. Then wash the article and polish in the usual way.
Compound For Cleaning Brass.—To make a brass cleaning compound use oxalic acid, 1 ounce; rotten stone, 6 ounces ”