Loam-patterns
Numerous patterns may be readily made from loam and much pattern lumber saved thereby; many, also, may be made quicker by this means, saving both time and lumber.
Straight pieces of shafting, pipes, etc., may be struck on a barrel to the diameter required, after which a little water blacking will separate the thickness, which may be struck thereon after drying the core. Or should such a pattern be required more than once, the outside diameter can be struck at once, dried, coated with tar, and dried again. Such a substitute for the wood pattern acts very well in an emergency.
If the pipe is a common socket, the bead and socket ends can be formed at once; but in the event of flanges they must be placed after the model is dry, as would be the case also if it were desired to affix a branch thereon. Bends of any description may be made from loam with either iron or wood templets and a former, each half being first struck on a core-iron to the core size, then dried, flanges fixed, and the thickness struck; first interposing a thin coat of water-blacking to separate the thickness from the core after the mould impression has been taken.
The bottom half of such a pattern needs a few brads driven into the body, the heads of which, protruding somewhat into the thickness, would prevent the thickness from falling off whilst it was doing duty for a pattern. A barrel core is thicknessed by wrapping a hay-rope on the core, and finishing off with clay and loam in the ordinary manner. Those unaccustomed to this method of producing a pattern will see by the above examples what the possibilities are when the emergency presents itself. See FORMER; TEMPLET; CORE-BARREL; THICKNESS; LOAM.