Great care is needed in the preparation of the resin mix prior to moulding. The resin and any additives must be carefully stirred to disperse all the components evenly before the catalyst is added. This stirring must be thorough and careful as any air introduced into the resin mix affects the quality of the final moulding. This is especially so when laminating with layers of reinforcing materials as air bubbles can be formed within the resultant laminate which can weaken the structure. It is also important to add the accelerator and catalyst in carefully measured amounts to control the polymerisation reaction to give the best material properties. Too much catalyst will cause too rapid a gelation time, whereas too little catalyst will result in under-cure.

Fillers are often added in quantities up to 50% of the resin weight although such addition levels will affect the flexural and tensile strength of the laminate. The use of fillers can be beneficial in the laminating or casting of thick components where otherwise considerable exothermic heating can occur. Addition of certain fillers can also contribute to increasing the fire-resistance of the laminate. In this case, I used calcium carbonate.

I let the resin mix rest for about 24 hours before use it. Catalysts are added to the resin system shortly before use to initiate the polymerisation reaction. The catalyst does not take part in the chemical reaction but simply activates the process. An accelerator is added to the catalysed resin to enable the reaction to proceed at workshop temperature and/or at a greater rate. Since accelerators have little influence on the resin in the absence of a catalyst they are sometimes added to the resin by the polyester manufacturer to create a 'pre-accelerated' resin.

First I put the accelerator, mixed them as shown in the first video and later added the catalyst. I put the final preparation into the mold and rotated it during several minutes, as you will see in second video. Takes approximately 4 hours to be ready to pull out of the mold.

Once the resin is cured, I pulled out the pouch from the mold as you will see in the third and fourth video. Cause I only have 1 mold of each model takes me 1 day to get a complete set. Hope I did not bored you with this technical explanation. Thanks to YouTube.com I introduced videos to my tutorials. Cool Is It not? May the Force be with you!