Figure 6
The AMBU mould compound has been developed to eliminate the necessity for heating or smoking the mould—it remedies all the pouring troubles and in addition, has chemical ingredients that aid in preventing the mould from rusting. AMBU mould compound is placed in a little sack, contained in each can, and the surface of the mould dusted with the sack, as shown in Figure [6].
The compound completely fills the pores of the iron, produces perfect castings with a cold mould and prevents the finished part from sticking. It does not wear off as quickly as the “smoke,” and dusting from time to time, while castings are being made will produce a high polish on the mould surface which will result in even better castings.
The mould in Figure [6] is the new AMBU Washburn combination link mould, which casts 15 parts, being reversible much like the ordinary “waffle iron.” The side being “dusted” casts four top connectors of different lengths.
POURING THE LEAD
Placing the mould as in Figure [7], the lead is poured in the four openings until the metal projects slightly above the top.
To pour properly first skim the dross as previously explained, then with the ladle, push the film of oxide away and dip into the clean pure lead. Pour steadily until the mould is filled and the metal projects slightly above the top. As it cools there will be quite a little contraction which takes up most of the excess lead.
Figure 7