We use polyester un-waxed (laminating resin) except for the final coat of resin which contains wax. If you use un-waxed resin laminating can be spread over several days. This gives me time to rest and prevents too much heat building up which will cause shrinkage and distort the beam. We use a thin CSM (chopped strand mat) layer as the initial layer and that gives a smooth finish that is ready to paint. The first beams I built were made with epoxy which was very stressful. It was a large boat and the each beam needed to be completed in one day. After that stressful time I developed an epoxy allergy and thought my boat building days were over. Since using polyester I’m back on track and enjoying every day building. Although building beams is not my favourite boat building activity, it’s not so bad. By using polyester laminating resin the job can be spun out over many days and I use the activity as a fill in job. Some people insist on using epoxy resin but in Australia it is now about 6 times the cost of polyester and there are horror stories of people who have developed allergies. I always use a mask and cover up when using polyester but so far no problems. Scarab 650 beams.A tooling gel female mould was made from a plywood mould painted with Jotun pengard and Imperite. It is not necessary to go to this much work but we wanted to use the mould for more than 4 beams in the future. |