Sealants Sealant/adhesive for sealing risers to polyethylene tanks. Impregnated, compressible and lightly adhesive foam tape expands up to Read More Sealant/adhesive for sealing risers to polyethylene tanks. Impregnated, compressible and lightly adhesive foam tape expands up to 0.75” to close gaps between mating surfaces. Length – 13ft.