Fig. 1309.
First, then, a thin scraper is liable to chatter, especially if used upon slight work. But the narrower the face on the end of the scraper, the easier it is to resharpen it on the oilstone, because there is less area to oilstone. A fair thickness is about 1⁄20 inch; but if the scraper was no thicker than this throughout its whole length, it would chatter violently, and it is for this reason that it is thinned at its cutting end only. Chattering is prevented in small and slight work by holding the scraper as in [Fig. 1308], applying it to the top of the work; and to reduce the acting length of cutting edge, so as to still further avoid chattering, it is sometimes held at an angle as in the top view in [Fig. 1309], s being the scraper and r the tool rest.
When the scraper is applied to side faces, or in other cases in which a great length of cutting edge is brought into action, a piece of leather laid beneath the scraper deadens the vibration and avoids chattering.
Fig. 1310.
It is obvious that the scraper may be given any required shape to meet the work, [Fig. 1310] representing a scraper of this kind; but it must in this case be fed endways only to its cut, if the work is to be cut to fit the scraper.
