SealBoss FlexGel is a low-viscosity, NSF-approved, single component hydrophilic polyurethane grout offering excellent penetration properties, superior strength and durability. At a mixing ratio of 1 part FlexGel to 10 parts water by volume, the mixed product has a super low viscosity of 50 cps. The product is capable of incorporating large amounts of water into itself, thereby forming a waterproofing gel. The ability of FlexGel to swell and increase in volume due to water absorption is one of the important features that differentiate hydrophilic grouts from their hydrophobic counterparts.SealBoss FlexGel is certified for water contact in accordance with NSF standard 61, for contact with potable water. SealBoss ® FlexGel can either react to a foam or a gel on contact with water based on the mixing ratio. The product forms a flexible gel at product to water ratios from 1:4 to 1:15. Less water results in a stronger gel. The gel time is about 1 to 3 minutes varying with temperature and water saturation. At low product to water ratios of 1:1 to 1:2 SealBoss® FlexGel reacts to a flexible and closed cell foam under pressure. To achieve most satisfying and permanent results, a combination of SealBoss ® FlexGel with other systems of our product line may be advised. Ask your SealBoss technician for details. The product is for professional use.