From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Article detailing the process of renovating worn vehicle parts using electro-deposition, developed during the war.
| Identifier | ExFiles\Box 50\2\ Scan172 | |
| Date | 24th August 1920 | |
| Reprinted from “The Commercial Motor,” August 24, 1920. REPLACEMENT OR RENOVATION? How Electro-deposition on Worn Parts Helped Transport in the War—The Romance of Renovation—Science and Salvage—An Industrial Application—From the Scrap-heap to the Finished Stores. THERE CAN BE few users of motor vehicles to-day who do not view with alarm the enormous increase in the cost of repairs and the very serious effect which it is having on the economics of road transportation. The heavy labour charges which the modern repair shop is called upon to bear is not the only factor contributing to the increased expense of keeping vehicles in good condition on the road; the inflated prices of spare parts, and the difficulty and delay which are often experienced in obtaining delivery of them have much to do with it. In a sense, the civil repair shop to-day is labouring under very much the same difficulties as were the Army repair shops in the later stages of the war. Then there was a period when the difficulty of getting spare parts was so great and the wastage and scrap in transport vehicles was so enormous, that the upkeep of the Army transport system in the field was a matter of the utmost difficulty and the cause of great concern to those responsible for its efficient maintenance. Electro-deposition Saved the Situation. It was during that period that the Army authorities, in their efforts to reduce the enormous amount of wastage that was taking place, turned to the process of electro-deposition as a means of salving a large proportion of the "scrap" and of cutting down their requisitions for supplies of new parts, which were straining severely the overtaxed resources of the factories at home. There is no question but that this process, which was developed during the war from the stage of experiment to that of practical utility, saved the country a vast amount of money, and enabled a very difficult period in the upkeep of the Army transport to be tided over. So far as is known, it was in the Army workshops that the first really successful application of the principle of building up large quantities of worn-out parts by depositing new metal on them by electrical means was made. It was the application of an old-established principle to a new branch of work. A little light was thrown upon the uses to which the process of electro-deposition was applied in salving parts which otherwise would have been scrapped, in a paper read a few months ago before the Institution of Automobile Engineers by Major B. H. {Arthur M. Hanbury - Head Complaints} Thomas, who had much to do with putting it on a practical and successful footing at one of the heavy repair shops in France. The paper dealt with the scientific aspects of the subject, but the story of how success was attained, after innumerable difficulties had been surmounted under most adverse conditions, might well be called a romance of renovation. Early attempts were not very successful. Following upon the well-known lines of electro-plating, it was usual to deposit on the worn surfaces first of all a layer of copper—a comparatively simple process—then on top of that a coat of hard iron. The chief difficulty was to get the layer of deposited metal to stick. Copper was found to be necessary in the early days in order to secure a reasonably firm adhesion of the iron, but it was really only a makeshift method, as the deposit so formed was not satisfactory when applied to parts subjected to wear, and was, of course, unable to withstand heat treatment. This is easily understood, as copper is a soft metal, and it cannot be expected that a wearing part should stand up indefinitely, with a layer of copper beneath an outer skin which could not be case-hardened. Correct Method Difficult to Achieve. The direct deposition of metal was obviously the ideal at which to aim, but it was one exceptionally difficult to achieve. While to secure adhesion was the chief trouble, and to ensure that the deposited layer of metal would not strip under wearing conditions, other problems equally baffling cropped up. Sometimes the deposit was porous, at others brittle—incomprehensible variations in the quality of work turned out, under conditions which were practically identical, had to be analysed and an explanation sought. It was only after a great deal of experiment and research work had been carried out that the process finally approached success. Many data were gathered and collated during the war period by Major Thomas and others, but even at the conclusion of hostilities the process could hardly have been claimed to be a commercially useful proposition. Revolutionizing Repair Work. Since then, however, under more peaceful conditions, which have permitted closer investigation, Major Thomas has continued his experiments, directing his efforts entirely towards the placing of the laboratory process on a footing which would make it a practical commercial proposition, the utility of which would be unquestionable, and which would bid fair to effect a revolution in the modern repair shop methods. In conjunction with Lieut.-Col. Kennedy, who, as commanding officer of one of the largest M.T. heavy repair shops in the war, had been able to appreciate to the full the possibilities of this work, a laboratory was established and equipped with all the incidental appliances necessary to the electro-deposition of metal for the purpose of renovating worn-out parts. They were encouraged in this pioneer work by the knowledge that the scope for the process, if it could be properly carried out, would be enormous. It needs little imagination to see that such would be the case. When it is considered that every day, in practically every repair shop in the country, expensive parts, costing, it may be, anything from £5 to £50, are being scrapped simply because the outer surface of the metal was worn away, although the wear may be almost infinitesimal—a few thousandths of an inch—it will be appreciated that the economies to be effected are such as to ensure a tremendous demand for renovation work. Simply because, until very recently, science had devised no means of replacing metal which had worn away, this scrap had come to be looked upon as inevitable. If electro-deposition be a practical process, it need be inevitable no longer. Cutting Down Costs. It is, we understand, the aim of the Electro-Ferrous-Engineering Co., Ltd., in which Col. Kennedy and Major Thomas are now concerned, to make such wastage unnecessary in the future. No claim is made by Major Thomas or his associates to have originated the process. Their claim—and it is one which appears to be amply justified—is that they have put it on a commercial footing, so that they are in a position to render the utmost assistance to those responsible for the repair and maintenance of motor vehicles—or, indeed, almost any class of machinery—to effect economies which are of the most vital importance at the present time. The scrap-heaps of some repair shops are astonishing. Often they consist largely of costly parts which are considered useless simply because a few thousandths of an inch of material are worn off them often over a small area. "Yes," says the critic, "that may be so, but then new parts are comparatively easy to obtain, and they don't cost very much." Now, with present-day conditions what they are, that argument does not seem to be a sound one. Spare parts are often by no means easy to obtain, and their cost is, as has been mentioned before, an inconsiderable factor in the heavy repair and maintenance charges which have to be met at the present time. So far as we can gather, what the sponsors of this new industrial process say in effect is this: "We will take your scrap heap—or most of it—and we will return the parts to you in such a condition that you can put them into your finished stores, or, if you like, straight into a vehicle; that is to say, we will return the parts to you in such a condition that they are equal to and indistinguishable from new parts, and we will do it for approximately Image Captions: (1) Coating the parts prior to immersion in the electrolytic bath. (2) One of the baths in which small articles are treated. (3) A case-hardening furnace. (4) Grinding a gudgeon shaft. (5) One of the deposition benches. (6) A corner of the machine shop in which the built-up parts are reground to size. | ||