TOP FLITE SUPREME MICRO-BALLOON FILLER is ideal for thinning epoxy and poly- ester resins to make fillets or repairing surface imperfections. New $4.99 (28% off). The ratio of microballoons to epoxy is a three-to-one mixture. Features: * Ultra-light extender makes epoxy or polyester resins lighter and more sandable. * Great for joints and fillets, or surfacing over imperfections in wood grain or in fiberglass cloth. * Convenient spout offers easy, no-waste pouring for clean,no mess use. * Compatible with aliphatic resins and acetone based glues.