Method of making a water resistant orthopedic cast

A method of forming a water-resistant orthopedic cast comprising applying to the cast bandage, while the cast bandage is wet with water, a fluorochemical selected from the group consisting of:

• (a) esters of the structure:
• ##STR5## where n is an integer of from 3 to 14 (b) Polymers containing 3% to 25% by weight of a polymerizable monomer of the structure:
• CH.sub.2 .dbd.C(CH.sub.3)CO.sub.2 CH.sub.2 CH.sub.2 C.sub.n F.sub.2n+1
• with a polymerizable vinyl compound selected from the group consisting of:
• ##STR6## wherein R.sup.1 is H or methyl, R.sup.2 is a saturated alkyl group containing from one to 18 carbons, R.sup.3 is a phenyl or alkyl substituted phenyl, R.sup.4 is hydrogen or saturated alkyl groups of one to six carbon and Y is fluorine, chlorine or bromine:
• (c) Polymers formed by the polymerization of monomers of the structure:
• ##STR7## wherein R is H or CH.sub.3, and n is zero or 1:
• (d) Fluorocarbon compounds of the formula:
• ##STR8## wherein R is selected from the group consisting of hydrogen, water-emulsifiable salt-forming cations and fluoroalkyl radicals of the formula --(CH.sub.2).sub.b --(C.sub.y F.sub.2y)--CF.sub.2 E, and wherein A is hydrogen or lower alkyl (C.sub.1 to C.sub.5), B is oxygen or NH, D and E are hydrogen or fluorine, m and n are integers from 0 to 4 inclusive, and totalling not more than 4, x and y are integers from 1 to 18 inclusive, and a and b are integers from 1 to 3 inclusive:
• said fluorochemical being applied to said cast bandage as an aqueous dispersion containing from 2% to 30% by weight of said fluorochemical said aqueous dispersion containing a cationic or nonionic surfactant to maintain said fluorochemical in said dispersion, and allowing the cast to dry at room temperature.