Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to sand fiberglass [title] Allow the fiberglass to cure in the sun. [step] If you are working with a new fiberglass component, it will have a thin layer of gelcoat on its surface. Gelcoat is an epoxy or resin-based compound that is used to line the molds when making fiberglass components.

Ending1: This prevents the color from fading as the new materials are made. If there is not an epoxy layer, you will have to sand this surface using a sanding sponge. Ending2: When you are treating fiberglass parts of a model, wait for the sealant to cure completely. [substeps] If you are working with fiberglass parts of a model at home, you may expose the fiberglass to bright sunlight for an hour during the process of repair. Ending3: Before sanding, let the fiberglass sit out in the sun for 2 to 7 days to cure the gelcoat. This process releases any air pockets from the gelcoat that would cause problems when sanding and painting. Ending4: [substeps] Fiberglass gelcoat can be purchased at any automotive store. Make sure to read the address that comes with the product or the instructions on the packaging.

Answer format: ending1/ending2/ending3/ending4