“SUN” SERVICE STATION

Sun (Auckland), Volume II, Issue 510, 13 November 1928, Page 6

“SUN” SERVICE STATION

rpilF ‘Motordom* section ol The Sun includes in its service to readers a x Queries and Answers Department, the object ot which ts to give accurate information regarding mechanical and touring subjects Whatever the particular puzzle may be in either diagnosing irritating troubles, or motoring information of any kind, “Headlight" will endeavour to help, or refer the point to men who are recognised automobile experts in their respective lines All communications must be accompanied by the inquirer’s name and address (not for publication), and sent to THE SUN “Service Station, Motordom.” THE SUN. Auckland. Answers will appear weekly in this column.

Yelton.—After a trip to Arapuni, 250 miles. I found the brake bands and drums on the “near side” wheel smothered with black grease running down the disc wheel on to the tyre. The same thing applied on the “near side” front wheel. Do you think it just a coincidence that it was the two “near side” wheels which were affected. Also you please tell me the reason for a screeching noise when the clutch is let in. while the car is stationary. Considering that the leaking grease occurred on two separate wheels, a front aad a rear, after a long trip, I would suggest that it was due to either or both of two reasons. Firstly that two much oil was put in those hubs, and secondly that the long running caused greater friction and more heat than running around town, causing the oil to melt. (By the way, be sure to keep the oil off your tyres.) Re the clutch noise. I have pretty vague information to go on. Is the noise in the clutch or in the floorboards? If the latter, perhaps the clutch pedal is scrapping on the boards.

D.W.Mr — I would consider it a favour if you could possibly give me information on the undermentioned inquiry. I understand that Duco can be purchased in a small quantity, namely a gallon Must Duco be sprayed or would it be possible to apply on scratched or mutilated parts of the body or mudguards of a car with a brush? If applied with a brush would it give the same surface finish as if sprayed with-

out removing the old Duco, having, of course, the defective part cleaned thoroughly? If the previous Duco must be removed before applying the new, what process must the mutilated parts go through in order to thoroughly remove same?

There is never a need to remove old Duco before applying new, as different coats of the lacquer will merge into one coat as soon as they touch existing Duco. Unlike paint, which is a number of separate coats, Duco becomes one coat from surface to metal.

You pan apply it with a brush, but this method is not recommended for the outside of a car, though it is quite good for interiors. There are now on the market hand spray-guns, I believe, with which you can spray the finish from the gallon pans. - At the same time, you should remember that painting and spraying are specialised trades, and your attempt probably will not equal the original finish placed on the car by a craftsman. I should recommend that renovations be made by an authorised Duco finisher, who has the equipment and space to do a satisfactory job.

A.H. —The outside edges of my two back guards are marked with white paint, where they have grazed various objects. The paint is very hard and seems to have gone right into the Duco. See reply to D.W.M. above. Perhaps it would be best to chip the paint right off, but make sure first that you can get the job neatly finished again.

THE INSIDE OF A TYRE GOODRICH CLAIM STRONGER BASE Exacting specifications are applied to all parts of the Goodrich Silvertown. but in the selection of the cotton, which composes the Goodrich Silvertown’s body, engineers and cotton experts have combined their knowledge and technical skill to get cords of? the highest qualifications for the proper service result in the finished tyre. Goodrich engineers claim that the following process assures the superiority of their product.. 1. Approximately 165 log staple cotton fibres are twisted together to form a single yarn. Five of these yarns are twisted together to form a thread. Three of these threads are twisted into a cord. 2. The inside difference between many ordinary cords and the Silvertown cord is in the number of yarns twisted into the cord. The Silvertow*n is known as 23/5/3 (the 23 indicating the gauge of the thread). Drawing a comparison between this and a sample of ordinary cord fabric we find that the ordinary cord is* constructed as a 23/4/3 —the comparison showing three less yarns in the ordinary cord than in the Silvertown. 3. The 15 yarns twisted together to form the Silvertown cord provide a tensile strength of 15.51 b. The 12 yarns of many other cords only provided a tensile strength of 13.751 b. 4. Important as the preceding facts are there is still another process that contributes to Silvertown’s long mileage and dependability—Silvertowns are made of Weftless Cord Fabric; ordinary cord tyres are made of cord fabric woven in wide sheets—the cdrds are held together by means of a weft or cross thread. Silvertown cords are brought from the mills in large spools. These cords are brought to sheet form over special rolls that thoroughly impregnate each cord with a cushion of rubber. The Weftless process gives the Silvertown more uniform elasticity, absolute uniformity of the rubber coating around each cord and an elimination of the sawing action caused by cross threads.

A Detroit company has introduced a 61-seater, double-deck, steam-bus. The compound engine has an output of 82 h.p. at 820 revolutions and the maximum steam pressure is 1,2501 b a square inch.