A composition of matter comprises 100-800 parts by weight polyethylenes and copolymers thereof having a melt index of 1-4 g/10 min., a density of 0.93-0.95 g/cc and a weight average molecular weight of 5-1.0.times.10.sup.5 ; 100-400 parts by weight polyethylenes having a melt index of 2-4 g/10 min., a density of 0.93-0.95 g/cc and a molecular weight of 6-20.times.10.sup.4 ; 0-100 parts by weight polypropylene having a melt index of 5-9 g/10 min. and a density of 0.8-1.2 g/cc; 0-150 parts by weight copolymer such as ethylene-propylene or ethylene-vinyl acetate; 0-100 parts by weight graphite or carbon black; 0.04-0.2 parts by weight antioxidant; and 0.1-2.0 parts by weight light stabilizer. A sealant is obtained by compression, extrusion or injection molding the composition described above. A polyethylene surface repair or reinforcing kit comprises the sealant or thermoplastic repair material of the invention, a thin, heat-resistant, adhesion-resistant barrier, and a polyethylene surface enzyme cleaner. A method of repairing or reinforcing a polyethylene surface comprises applying over an area of the surface in need of repair or reinforcement the sealant or thermoplastic repair material of the invention, heating the area of contact between the sealant and the surface to produce thermal fusion therebetween, and cooling the fused surface. A method of preparing a thermoplastic polyethylene surface sealant or thermoplastic repair product comprises blending the composition of the invention, and compression, injection or extrusion molding the blend to form a product of a desired shape.
William A. Mallow