Items and materials not described in the manual are explained below.
The M1 Thickener (Mil-t-589a), chemically a mixture of 25 percent wt. aluminum naphthenate, 25 percent aluminum oleate, and 50 percent aluminum laurate, (or, according to other sources, aluminum stearate soap) is a highly hygroscopic coarse tan-colored powder. As the water content impairs the quality of napalm, thickener from partially used open containers should not be used later. It is not maintained in the US Army inventory any more as it was replaced with M4.
The M2 Thickener (Mil-t-0903025b) is a whitish powder similar to M1, with added devolatilized silica and anti-caking agent.
The M4 flame fuel thickening compound (Mil-t-50009a), hydroxyl aluminum bis(2-ethylhexanoate) with anti-caking agent, is a fine white powder. It is less hygroscopic than M1 and opened containers can be resealed and used within one day. About half the amount of M4 is needed for the same effect as of M1.
AIPD - CM3209 - Flame Field Expedients
