Here’s a list of the most frequently asked questions, listed by product. As a reminder, you can always contact our Customer Service Center 8AM – 5PM M-F Eastern Time (closed on holidays) at 1-888-605-0636.


Q. Can you heat up a body filler to accelerate the sanding / cure time?

A. Yes, fillers can be heated to accelerate the cure or to adjust the cure during colder weather. The general recommendation is to not exceed 120°F (50°C) for any longer than 15 minutes.

Q. What's the difference between a fiber reinforced filler, a regular filler, and a putty / finishing glaze?

A. Fiber reinforced fillers provide strength and durability to the repair area when needed. These reinforced fillers contain fiberglass and are normally used over a welded area, to repair surface cracks in fiberglass, or to fill small holes, etc. A regular filler is typically used to repair dents, to smooth out rough fiberglass, and should be used over fiber reinforced fillers as fiber reinforced fillers will not provide a smooth enough finish for priming and painting. A putty/finishing glaze is basically a thin body filler designed for finish work over body filler and to repair small minor damage, such as door dings, hail damage, and scratches.

Q. Can Evercoat fillers be applied over bare metal? Can they be applied over paint?

A. Evercoat fillers are designed to work over bare, properly prepared substrates such as: steel, aluminum, galvanized metal, fiberglass, and SMC. Fillers and putties will normally work OK over properly sanded (80-180 grit) cured OEM paint. However, with so many different types of aftermarket paint available (lacquer, enamel, urethane, water-based), and without knowing the extent of the cure for the paint, or age of the paint is unknown we generally recommend that all paint be removed where filler is to be applied.

Q. How long should I wait to apply body filler over an epoxy primer?

A. Some coating manufacturers may have a defined time and procedure for the application of polyester filler, so contact the coating manufacturer for their recommendations. If there is no defined time or procedure a general guideline is to allow 24 hours and sand that area lightly with P80 up to P180.

Q. Can polyester fillers be applied over a self-etch primer?

A. No. The phosphoric acid in most self-etch primers that are used for automotive refinishing inhibits the cure of the filler and creates an adhesion problem. If a corrosion protection coating is preferred we recommend to use an epoxy primer and follow the coating manufacturer’s recommendations.

Q. What sandpaper grit should I use to sand Evercoat fillers?

A. Evercoat fillers and fiber-reinforced fillers should be sanded with P80 grit and finished with P180 before applying a finishing putty. The general recommendation is to sand the filler or putty with the same grit that was used to prepare the surface. This provides a higher quality finish at the feather edge of the repair.

Q. How much cream hardener should be used to activate body filler?

A. Polyester fillers require a 50:1 mix ratio of product to cream hardener. An easy way to do this is to dispense a ribbon/bead of cream hardener from edge to edge across the center of a 4″ (10cm) diameter puddle of filler (2% by weight). Puddles larger than 4″ in diameter will require additional hardener and puddles smaller than 4″ in diameter will require less hardener. A Perfect-Mix™ guide can also be used – find these under the domes of appropriate products and available for sale at your retailer.

Q. Why is the body filler sticky or soft to touch?

A. The filler may not have been catalyzed properly. Make certain the mixing directions for the cream hardener were followed. Filler should be applied between 60-90 degrees Fahrenheit (15-32°C), so be certain that the product and substrate are at similar temperatures. If the material is only partially cured, it should be removed and then reapplied.

Q. Why did the body filler not adhere properly to the surface?

A. The surface was not properly prepared or was made of a material the filler could not bond to. The surface should be sanded with P80 grit sandpaper, then wiped clean with acetone. Some filler’s may not bond well on some surfaces such as galvanized steel, aluminum, SMC and other plastics.

Q. Why do I have pinholes in the body filler?

A. Pinholes are a result of trapped air in the body filler. Applying the filler too thick can also cause pinholes. To eliminate pinholes, you must properly mix and apply the filler. For more information on the proper technique visit our YouTube Channel.


Q. Can you use a polyester resin as a coating without using a fiberglass fabric?

A. No, resin alone has no strength and will crack if not used with fiberglass cloth, mat, or tape. The strength of Fiberglass Resin comes from fibers or cloth saturated within the resin. Second, polyester resins do not have a UV inhibitor built in, so they need to be finished with a UV protective coating to avoid damage from the sun and exterior weather.