How to Fiberglass: Fixing a Cracked Kiteboard

Step 7 Lay down the Fiber Glass

Take the first piece of fiberglass that is going to be laid down and place it on the surface. Use a brush loaded with the laminating resin and begin to paint a thin layer of resin over the fiberglass. As you paint more resin onto the mat, it will turn translucent and lay down nicely on the surface below. Work resin from the center of the mat out to the sides. This process is called "wetting out" the fiberglass.

Once the fiberglass has been thoroughly saturated with resin switch from the brush to the scraper, and just as you would apply spackle to a wall, use the scraper to apply a thin even coat of the resin all over the fiberglass. Work from the center of the piece to the perimeter of your work. Be mindful of any bubbles or folds in the fiber glass as you are trying to lay down the layer of fiberglass as smoothly and evenly as possible.

Don't worry about the glass extending beyond the edges of your project surface. The extra bits can be sanded off easily once the resin dries.

Ribbed roller tools make this process even easier since they are great at getting air bubbles out of the fiberglass and work really well at getting the fiberglass to lay down.

Once the first layer was down we began to layer more fiberglass on top. Each successive layer won't require as much resin as the previous layer did since there is usually excess resin made available from the scraping process.

You can lay down as many layers as time permits before your resin becomes too hard to work with (between 15 and 30 minuted depending on your system). If you're planning on laying down many many layers, think about mixing multiple smaller batches of resin rather then one giant batch and rushing through the work.

When all the layers are down and the resin is spread evenly and completely throughout the fiber glass it's time to let things dry thoroughly. This can be hour, or it can be overnight depending on temperature and what resin system you are using.

You can control how quickly polyester resins cure (within a reasonable range) by changing the amount of MEKP that is added to the resin. Epoxy resins cure at different speeds depending on temperature, but generally speaking, the only way to manipulate drying times reliably is to buy resin systems that are specifically formulated to go off in either long or short amounts of time.