Once you have decided on what type of sealer you want to use, the next step is determining if you want to use a water-based or solvent-based sealer. All sealers require a method of delivering the polymers to the material, whether it is going to be a surface coating (topical sealer) or going to penetrate into the pores of the material (penetrating and impregnating sealers).
The polymers are dissolved or dispersed in the carrier, either water or solvent, and then delivered to the material by the carrier. When the carrier evaporates, the polymers are left behind to react with the material to provide a protective barrier.
With the advances in polymer technology, today’s water-based penetrating sealers are able to provide comparable protection to solvent-based penetrating sealers in most materials. In porous and extremely porous materials, water-based sealers often are able to seal more effectively and with less coats than solvent-based sealers. Unless applying several coats, solvent-based sealers can penetrate too deeply to provide an adequate seal in very porous materials.
Sealing Very Hard or Dense Materials
In certain cases, however, where the material is particularly hard or dense, like polished granite or porcelain tile, water-based penetrating sealers may not be able to be absorbed as easily or deeply into the pores of the material.
This is a result of the water-based sealers having a higher surface tension compared to solvent-based sealers. Sealers with lower surface tensions are able to penetrate more effectively into the pores of hard and dense materials. The sealer will still be absorbed into these types of materials but may be less durable and not last as long.
Low VOC and Easy to Use
Generally, water-based sealers are regarded as easier and safer to use than solvent-based sealers. Most water-based sealers are considered low VOC (Volatile Organic Compounds). Sealers that are high VOC can produce harmful vapors that are dangerous for people and the environment.
Fewer VOC Restrictions
Low VOC sealers produce fewer fumes, making them less hazardous and more easily used indoors when compared to high VOC sealers, which are often solvent-based. Low VOC sealers also do not face the regulatory laws regarding the sale and transport of larger sizes, such as of a gallon or more. This becomes a factor in states that are considered VOC restricted.