Seamaster Syntasilk Wall Sealer (Solvent Based) 1800 works best as a sealer for both new and old building especially on new plastering surface. The acrylic modified solvent-based sealer is able to withstand alkaline attack, resist water and efflorescence and has excellent adhesion property. Syntasilk allows your wall to exhale humidity, anchor to substrates and reduces water pocket on top coats.