444 



THE INDIA RUBBER WORLD 



[August 1, 1911. 



GARAGES. RUBBER AND REPAIRS. 



ALMOST every garage, big and little, dips to a degree into 

 the rubber business. For exanij^Je, they are factors in the 

 waste rubber field for they all advertise "Old Rubber Bought 

 and Sold." But it is in repairing, however, that they really 

 shine as rubber men. Just to size up the business, an I.nuia 

 Rubber Worij) reporter recently visited several garages in and 

 about New York to find out just what was being done. 



The first was a tiny place, housing not more than fifteen cars. 

 They, however, made 2.509 repairs last season. Of these 200 

 were shoes retreaded, 500 sections to repair blowouts, and the 

 rest patching of inner tubes. They guaranteed certain tires 

 where they warranted them to run 1,500 miles after repairing. 



.\ big city garage figured that they did about 1,500 sections 

 a year. For little jobs, such as repairing tubes, cutting 

 down sizes, etc., they claimed that they averaged 50 a day 

 in the busy season, and for the year did about 6,000. Both 

 were equipped with vulcanizers. gas heated, and purchased 

 their stock, cement, etc., from the tire manufacturers. 



Talking with the re- 

 pair men, the follow- 

 ing points were de- 

 duced. 



There are two prin- 

 cipal causes for re- 

 pairs, rim cuts and 

 punctures. The first is 

 brought about by a 

 deflated tire, which 

 may have been occa- 

 sioned by a puncture 

 or by carelessness in 

 tightening the nipple 

 after inflation, or by 

 some defect in the in- 

 ner tube or shoe de- 

 veloping while eii 

 route. A burst tire 

 often dates back to a 

 bruise on a sharp stone 

 and develops by slow 

 degrees. The bruise 

 has strained the fabric, 

 perhaps split it on the 

 inner ply of the shoe 

 or casing. 



In repairing a rim 

 cut a section one or 

 if the duck plies are 



ii'iiAi, .Vl'Tomobile Repair Shoi 



two inches wide is removed, and 

 not seriously worn the fabric is 

 coated with cement, a piece of unvulcanized gum adjusted to 

 replace the part removed and the tire thus repaired is placed in 

 the vulcanizer. Where the fabric is injured care is taken to re- 

 move every particle of dirt or sand. Some repairers cut out 

 the worn duck and insert a new piece, others apply cement and 

 make a surface repair. But frequently the injury is deep seated, 

 the shoe being not only burst on the outside, but the duck, to the 

 innermost ply, split longitudinally. Here the repairer gets in his 

 expert work. For the length of the split, plus a couple of inches 

 for working margin, the rubber surface of the shoe is removed. A 

 section of the torn duck is then removed from the first outer ply. 

 Then from the second ply a section is removed, say three-quarters 

 of an inch smaller on all sides than the piece first removed, 

 and so on through all the plies of duck of which the casing 

 is made, giving in appearance a succession of steps, the inner- 

 most one corresponding in area to the size of the in- 

 jured section, the area of each section removed increasing 

 in the manner described. This method gives the patches a 



margin that ensures sciure attachment t^i the fabric of the tire. 

 The injured portions having been removed, the surfaces ex- 

 posed are washed thoroughly with naphtha and coated with 

 cement, then two plies of frictioned fabric are placed on the 

 inner surface of the casing, and so adjusted as to cover the 

 section to be repaired and have a margin for adhesion. The 

 rebuilding of the plies now being fitted nicely to the space cut 

 out for it, and "stitched" down along the edges with a hand 

 roller, care being taken that no air remains between the plies. 

 The last and largest of the duck patches having been applied 

 the whole is covered with new gum. 



The ingenuity of the repairer is further shown at this stage 

 of operation in his preparation of the ply of pure gum that is to 

 supply a new wearing surface for the shoe. After removing the 

 old tread, dove-tailed notches are made in the edges, and in the 

 piece of new gum that is to complete the repair, notches that 

 correspond in size and location. These are adjusted, the one 

 to the other and form a stronger union than could be secured 

 by the abutting of straight edges. 



The section wound witli strips of muslin is then placed in the 



vulcanizer, and in 30 

 minutes, more or less, 

 the job is finished. 



The repair of an in- 

 ner tube is a compara- 

 tively simple matter, 

 but it is a mistake to 

 suppose that a surface 

 patch is sufticient. It 

 should be double ; one 

 on the inner surface of 

 the tube, and one on 

 the outside at the point 

 of injury, the inside 

 patch being consider- 

 ably the larger of the 

 two. The surfaces of 

 the tube (inside and 

 outside), are rough- 

 ened by use of a buflf- 

 ing wheel or emery 

 cloth, and, by use of 

 naphtha, all "bloom" 

 or dust removed. This 

 creates a surface neces- 

 sary to the proper ad- 

 hesion of cement. 

 Workmanship comes in 

 here also, to make a patcli that will be symmetrical as well as 

 strong, and not a "kncb" or lump, that by constant rul)bing 

 against the inner surface < i the sliue will create in time another 

 weak spot. 



To attach a rivet studded leather tread the outer surface 

 of the tire and the inner surface of the non-skidding strip are 

 roughened, cleaned with naphtha and coated with cement, 

 which is allowed to dry for a short interval. The strip is 

 then slipped upon the shoe and the hand roller completes 

 the work. Care should be taken to remove every trace of 

 moisture. Wet weather is said to interfere in no small de- 

 gree with the production nf a satisfactory job. 



Where the duty on a consignment of oil-resisting hose was 

 recently assessed as "manufactures in chief value of metal." at 45 

 per cent, ad valorem, the importers protested, claiming a rate of 

 30 per cent, under the paragraph for flexible metal tubing or hose. 

 The general appraiser sustained the higher rate on the ground 

 that cotton-canvas hose, bound with wire, could not be included 

 under the latter classification. 



