The attractive characteristics of polyester-glass composites have led to their use in many industries, but using them as structural elements requires knowing their mechanical properties. This paper presents processing methods of polyester and glass scrap and their use in the production of new composites. This scrap, called the recyclate, was pre-crushed, ground, and then passed through sieves to obtain the desired fractions. Composite materials with added recyclate were made by hand lamination. Composites were made and then used to conduct appropriate tests to determine the degree of cure of the resin, and to determine the effect of the polyester- glass recyclate content on the hardness of composites. For this purpose, rectangular panels with a thickness of g = 8 mm were produced by manual lamination. Each plate contained 0% glass mat, 10% resin, and 20% recyclate with granulation ≤ 1.2 mm and ≤ 3 mm. Then, test samples were formed from each plate. Hardness measurements were performed using the ball-pressing method. In addition, structural studies were carried out to determine the correlation between the structural and mechanical properties of the discussed materials. The obtained test results showed that the recyclate content and its granulation clearly affected the mechanical properties of the tested composite materials.