Epoxy, lead & carbon
As an industrial engineer who has worked with advanced materials for many years, I am continuously amazed at how people cling to old technology in the face of overwhelming evidence supporting newer materials. At the outset, I should point out that I own an older Tartan 3500 that does not incorporate the newer technologies (the newer Tartans do) that I mention below. Looking forward to buying a new boat, I've spent a good deal of time investigating these materials choices.
Epoxy resins unquestionably produce a much stronger, lighter and stiffer laminate. The ONLY reason that most sailboat manufacturers continue to use polyester resins is that they cost a fraction of epoxy resins. Epoxy is far more environmentally friendly since it produces no styrenes. Although far more costly to use in the manufacturing process, epoxy resins result in a far superior structural product. Tartan pioneered the use of these resins in their products 6-7 years ago. Others are now starting to follow; Hanse provides an option for epoxy in its larger boats at a considerably higher price. The only reason that manufacturers continue to use polyester resins is COST.
Lead is unquestionably the best choice in materials for keels due to its much higher density, which dramatically influences the designed righting moment. The builders that use iron keels do so soley to save money. The compromise is found in a lesser rig design to accommodate the inferior righting moment. Lead keels also have a much longer life than iron by reason of the corrosion characteristics of iron. Again, the only reason that some builders use iron keels is COST.
Carbon spars are FAR superior to aluminum. They are less than half the weight of aluminum, and are stronger as well. Racing sailors are well familiar with the performance advantages of carbon spars. But as a cruising sailor, the advantages are very apparent as well; less weight aloft produces a much better sailing motion and an easier rig to manage. The suggestion that carbon masts are more susceptible to lightning damage is simply not supported by any facts. Additionally, boats with carbon rigs are fully insurable by all major marine insurers. Again, the only reason that most manufacturers use alloy spars is for reasons of COST.
Most quality sailboat manufacturers have plans to incorporate epoxy resins in their laminates, and provide carbon spars as standard materials. Only considerations of cost keep them from getting there. Tartan go there years ago by investing in advanced materials technologies, and now lead the pack.