b. Preparation of ingredients. Before mixing blends, the following steps should be taken:
(1) Gasoline, diesel oils, and fuel oils. These fuel materials should be allowed to stand quietly for at least 30 minutes to permit any small quantity of water present to settle to the bottom. When transferring the fuel to another container, remove the fuel carefully so that no water is remixed with it.
(2) Crankcase drainings. If possible, crankcase drainings should be allowed to stand quietly in a container for at least 1 day. When pouring, take care to prevent the transfer of any of the sludge which may have settled in the bottom of the container.
c. Equipment. An open-head 55-gallon or 42-gallon drum and an improvised wooden mixing paddle are used. The paddle should be approximately 5 feet long, 2 inches wide, and 1 inch thick. A metal paddle should not be provided because of the danger of striking a spark from the drum. Five-gallon cans may also be furnished for measuring and transferring ingredients. Clean, unrusted, steel storage drums should be at hand. They should be at least 16-gage to have sufficient strength to withstand the internal vapor pressure of the fuel.
d. Stirring. All the ingredients should be stirred in the drum with the paddle until they appear to form a uniform mixture. This should require approximately 2 minutes.
e. Crankcase-draining blends. If crankcase drainings are used as an ingredient ([Par 36b]), it is preferable to allow the prepared mixture to settle for 24 hours after stirring, because the gasoline in the mixture may cause additional sludge to be deposited. Even after this settling period, it is recommended that the mixture be poured through cheesecloth or some similar fabric before the flame thrower is filled. Crankcase-draining blends should be allowed to stay in the flame thrower only long enough for completion of a mission, because additional sludge which may form from standing will clog the weapon.
f. Transferring. The mixture should be transferred either directly into the flame-thrower fuel tanks (Pars [37] through [40]) or into storage drums. ([Par 35h])
g. Emergency mixing in fuel tanks. In an emergency, mixing can be done in the flame-thrower fuel tanks by adding the ingredients in correct proportions and then shaking or stirring.
h. Testing fuel. Before fuel is used on a mission, it should be tested, if possible, by being fired from a flame thrower.