“If you have too many irons in the fire, some of them will burn.”
In putting on new tires, proceed as follows: First, straighten the iron edgewise, then lay it on the floor and roll the wheel over it for measure, and cut the tire from one to two inches longer than the wheel will measure, for the tire will shorten in bending, because, first, the iron is upset on the inner side, and, second, it takes three thicknesses of the iron to make up for the stock taken away by the fact that the whole thickness of the material is outside of the measure taken; and, in order to have enough, cut the tire off long enough. Next measure the wheel with the tire wheel, or what is generally termed the “gauge wheel,” and then measure the tire after it is bent in the Buffalo tire bender. Now if the tire is for a wagon and is one-half inch thick, cut the tire the same length as the wheel, if the wheel is much dished. If the wheel is straight, cut the tire one-fourth of an inch shorter than the wheel, for if the wheel is straight, you may have the tire from one-half to three-fourths of an inch shorter when it is welded than the wheel; but if the wheel is dished and easily bent, the tire should not be over one-fourth of an inch shorter when welded and ready to put on.
In carriage and light wheels, the tire should not have more than one-eighth of an inch draw; and if the wheel is much dished, the tire should have no draw at all, but be even with and the same size as the wheel.
When the tire has been cut the right length, scarf the ends. In scarfing, let the flattened edges spring out as wide as possible; then place one end on top of the other, and fit them snug together, and the flared-out corners of the top end should be bent down over the bottom end. This will hold the tire when welding in the fire. To rivet or split the tire for welding is a method used by amateurs or third-class men, but is never resorted to by experienced smiths. For welding fluid, use coarse sand, and when the tire has the right heat, place on the anvil, but, in so doing, place the tire over the inner edge of the anvil, about two inches from the scarf, and hold the tire in such a manner that the scarf will not touch the anvil before you are ready to strike; and when you strike, hit with the edge of the sledge or hammer directly over the end of the bottom tire, for this end is thin, and, if the blow is not over it, the moment it touches the anvil, it will cool off, and then this end will not stick, and you have only half a weld. This is important, and is also observed by all expert tire welders.
Expansion of Tire
There are many ways in which to heat a tire in order to get it to expand so as to slip over the wheel. For a light tire, very little heat is needed. A few heats in the fire of the forge is enough, for such a tire should, as before mentioned, have only one-eighth of an inch draw; and when we know that a tire will expand, when hot, three-sixteenths of an inch per lineal foot, it is clear that about two feet of heat is sufficient. A tire five feet in diameter will expand three and one-half inches.
Tire in Sections
In the olden times, tire was made in sections, and nailed on. We can understand that then the wheel had to be made stonger than at present. The endless tire is a great improvement over the primitive tire in sections.
In resetting old tires, first mark the tire and felloe with a center punch or chisel. Then take out the old bolts, if there are any. This done, strike with the hammer on the felloe, and the tire will come off, but remember to strike on the inner side of the wheel, for in case you should mark the felloe, the marks will then be where they are not much noticed. Still it is better to use a block placed on the felloe to prevent marking the wheel. For wide tires, a lever press should be used to press the tires off with. Next, wedge the spokes if they are loose, and if the wheel is felloe bound, saw off the felloes, so as to give the tire a chance to draw down on the spokes. Upset the tire in a Buffalo Shrinker, and give the draw according to the size and strength of the wheel, but not over an eighth of an inch for buggy tire, nor more than three-fourths of an inch for heavy wagons.
Thousands of carriage wheels as well as wagon wheels are ruined every year by ignorant smiths. It is better that the tire should have too little draw than too much; for a dished wheel is a ruined wheel, and there is no remedy but to make the wheel over, and put in new spokes.
Back-dished wheels. It is no use to try to cure a back-dished wheel by setting the tire and giving it a good strong dish, for this will be only a temporary help. In the first quick turn, if the wheel is loaded, the wheel will spring back. To remedy a back-dished wheel you must pull out the spokes, and put in others with the right slant or taper in the spokes, to give it the right dish. The “faith-cure” smith will tell you to screw it right with a screw, and let it stay for some time; but this is only, as I said, a “faith cure,” and of no avail. There are many different ideas about the tire setting, and to refute all these whims and fads would take a volume, and, without wishing to be counted arbitrary, I will say that the method described is the only one, in order to get the best results. We often read in our trade journals of smiths who boast that they never measure either the wheels or the tire, but “set them on a guess,” and they are “always correct” when put on. I don’t believe in guesswork. A mechanic must learn to use the rule and the square. What would you say of a tailor you went to for a pair of pants, and he told you that he would not need to take any measure, as he always made his clothes on a guess. Now, a pair of pants are about thirty-two inches long, and a difference of about one-half inch would not make much difference; but you know that the tailor might make the pants two inches out of the way, and therefore you would not want this man to make you clothes. A tire is about fifteen feet long, and one-fourth inch too much draw would ruin the wheel, and there is no man living that can tell the difference of three inches in a tire by simply looking at it. So we see how absurd such talk is, and it is the talk of the botch; still it will be presented through our trade journals, because the editor was not qualified to know the difference. I will not pay any attention to ideas like the above, and if any of the readers of this book should want to know why such and such a method is not mentioned, let me answer: The object of this book is to let you profit by my experience, and you should pay no attention to this or that. When you get older in the trade, you will see it without looking through my spectacles, and save yourself much time and poor work.
There are different tools made for the putting on of the tire, and for the holding or measuring of the tire. Any of these will answer, so I shall take no space for the description, as these are well known to every smith. There are also different methods to cool the tire, as well as heating, and you can use the method you can best afford.
I have very little to say in favor of cold-tire setting in repair work. In factories where new work is made, they set the tire cold to advantage, because it is time saving. The tire then is welded, and the measure larger than the wheel. The wheel is then put in the machine, the tire placed around it, and the pumps that work the rollers started. Of course, it is done quickly, but there is no uniformity in the work; one tire may have a quarter of an inch draw, while the other may have one inch draw. The man at the lever will simply let it shrink until he hears the spokes crack while they are pressed up in the hub. One wheel may give a loud crack as soon as the tire touches the rim, while the other may give no sound of warning at all. The man at the lever must use his own judgement, and guess when to stop. Still, in heavy work, the machine is not a bad one, but it is quite different for light work, and especially in a repair shop. When a set of carriage wheels is brought to the shop to be set, in 95% of the cases the spokes are loose, and must be wedged, which cannot be done without taking the tire off, and the cold-setting man puts them into his machine, tightens the tire, and then we have a botch job which is liable to ruin the wheels. A great percent of the wheels are felloe bound, and then the tire must come off; for to set a tire on such a wheel is a sure ruin of the wheel. The fact is that there are very few cases when a tire can be set to advantage without taking it off from the wheel, and many a machine will ruin any wheel, no matter in what condition, by forcing the spokes loose in the hub and bending them out of shape. My advice is, be careful in using the cold-tire setter in repair work.