Repairing Cut Treads.

Sun (Christchurch), Volume VI, Issue 1790, 8 November 1919, Page 5 (Supplement)

Repairing Cut Treads.

Every stone chip, piece of glass, bit of iron or tin, switch point and the like inflict cuts on the toughest tread when fairly hit by the tyre. If even one of these is neglected it may cost thousands of tyre miles. A tread cut is very much like a wound on the sole of a runner's foot. If he runs with it, the pressure of his weight will extend the cut and make it gradually larger. In a tread cut the results of inattention are very similar. The elastic tread rubber is constantly spread by the weight of the car and the shocks of the road, so that even a small cut in a new tyre enlarges rapidly.* At the same time dirt, sand and small stones are forced into the

wound until they go entirely through the tread and into the carcase. Water, of course, also enters, furthers tread separation, and rots and weakens the carcase. Eventually a stone, or even a hump in the pavement, hit at a fair speed, will hring a had blow-out. It may be so bad that neither tube nor carcase will be able to deliver more than a fair number of miles for. the money invested in repair. Inspect tyres daily. Have all tread cuts taken care of promptly. If repair labour is scarce in your locality, do the work yourself if the cuts arc still fresh and not too large. Never try to repair an old cut without getting expert advice on it. If any tread separation or fabric rotting has set in, repairing the cut

without paying attention to these condiions is the very worst thing you can do. If you wish to repair new cuts yourself, follow faithfully the following directions:—-Take an old toothbrush or a clean rag on a stick and dip it into gasoline. Thoroughly scrub out the cut with it, making sure that all dirt and grit are removed. After scrubbing thoroughly, scrape the edges of the cut with the blade of a knife to make absolutely sure that nothing is imbedded in the rubber and brush vigorously a second time. Open a tube of patching cement, squeeze some of it on a flat splinter of wood and apply it thoroughly throughout the cut. Apply at least two coatings and make sure that

every portion of the cut is covered. Let the first coat dry thoroughly before applying the second. When the second has dried a few minutes, be ready to put in the tyre putty. Cleaning the cut, applying the cement as here directed is absolutely essential to a good repair. Without it not even the best of tyre putty can long -withstand the constant stretching of the tread and the hammering of the road when the tyre is put back into service. Open a can of tyre putty, take out a pinch about twice as huge as the cut would seem to require, and work it between the lingers and thumb. Then force it into the cut, ramming it down with your knife blade or a screw-driver, so that it is crammed into every crevice and pore of the

cut. Use more than enough to fill. Be sure that the putty sticks up above the face of the tread, for good tyre putty will shrink when it is left to "dry"—or, as rubber specialists say, while it is curing. Those desiring a particularly good job should wrap a cloth bandage tightly around the filled cut while it is "curing." Let the tyre stand four or five hours, or, if possible, over night, in order to let the putty "cure." Then trim off the rough edge of tlic filling with your knife (first wetting the knife) until the hardened putty is everywhere flush with the face of the tyre. The lyre is now ready for use. The putty will stand wear fully as long as the rest of the tread.