Its vital to keep the resin: glass ratio of 2-2.5: 1 correct and air out. After wetting and placing the first layer of matting down, roll resin through and then only apply more when needed. Repeat with another layer if necessary; this will save resin and improve the properties of the laminate.
3″ and 6″ Paddle Rollers and Single Wheel Rollers are available, as well as a set of the 3 rollers.
See the How Do I work with Fibreglass? article in the Technical Articles section