Curing/Sealing

Latex Vs. Alkyd Paint

It can take considerable time for a latex or alkyd paint to fully cure after application. Most latex paints are dry to touch after one hour and dry to recoat after four hours, but it can take up to three weeks for all of the solvent film-forming additives to come out of the product. Maximum water resistance is not achieved until the solvent has evaporated. Alkyd paints continue to cure after they have dried (16 hours). Maximum hardness and abrasion resistance for an alkyd paint usually takes 3-4 weeks.

Alkyd Paint

Alkyd paint has very poor alkali resistance. The alkalinity of a damp concrete surface can be quite high. Alkali attacks the resin system in an alkyd and makes it soft and sticky (saponification), resulting in poor adhesion. This situation is most likely to occur on concrete floors where there is an occasional moisture problem in the concrete. If an alkyd is saponified, it must be removed before the surface can be recoated.

Alkyd Sanding Sealers

Alkyd sanding sealers are clear coatings that are easy to sand. When solvent comes in contact with wood, it causes the grain of the wood to raise, making sanding necessary. Sanding sealers are recommended for use as a first coat on new wood or over wood stains. The materials in sanding sealers that make sanding easy can interact with polyurethane over time, forming a slick hard finish, causing peeling of the polyurethane from the sealer. Sanding sealers should only be used under alkyd varnishes.