... for forging steel as well.17 CASTING METAL PARTS investment will adhere to the finished casting. With a stiff bristled brush and a good laundry soap, scrub the casting thoroughly to remove all ... one-half pennyweight of extra metal to compensate for the difference. A little extra metal can always be used in the next casting: also it gives the extra push, in casting, to fill the mold.The ... method is slightly more difficult; a neat bend can be achieved with a little care.4 CASTING METAL PARTS PLASTER CASTING If you decide to make a few pistol frames, you will find it much easier to...