Hello, just a little info from your neighborhood NYC Sonneborn Rep.
Sonneborn's Sonolastic NP-1, (a urethane sealant) can be used for single pane
window glazing. I strongly suggest using a primer for glass and metal
surfaces. The primer is # 733. Allow the primer to dry for about 45 minutes
until it looses the tackiness. Once the primer dries, apply either
Sonneborn's NP-1 or for a harder sealant try Sonneborn's Ultra. Tool the
sealant and allow it to dry for 7 days before painting it. The technical data
sheets for application procedures on these products can be found at
If you would like the local rep to visit the site, please e-mail me and I
can arrange that for you. Hope this information is helpful.