High-build two part epoxy primer and barrier coat for use above and below the waterline Excellent for gelcoat blister prevention and repair work on fiberglass boats Provides superior protection on all underwater metals Easy to mix and apply by roller or spray. No sanding required. Fast drying primer creates a flexible, durable epoxy barrier coat. Available in White or Gray in Quart or Gallon sizes. Coverage: 225 sq. ft. per gallon (at 7 mils wet). Thinner: TotalBoat Epoxy Primer Thinner 200.