Pene-Krete is a non-hazardous, spray-applied, penetrating sealer for use on portland cement substrates. It creates a crystal-like shield and purges unwanted impurities from the concrete. The crystals tie the concrete matrix together, yielding more dense concrete. Coating performance in enhanced, as water vapor is not able to move efficiently through the slab. Super-Krete International, Inc. 800-995-1716. .