An investigation into post-curing methods of composite mouldings, applied to small boat building companies.

The aim of this report is to improve the focus on the use of Post-curing Methods of Composite Mouldings applied to small boat building companies and identify some key points which could be used in management decisions about yacht manufacturing. \n \nCurrent methods of post-curing are reviewed, together with the somewhat sparse literature available on stabilisation of mouldings, curing schedules and oven features. \n \nThe methodology includes industrial visits & interviews, the application of thermodynamics, studies of other industries using composites and advice and guidance from experts in the fields of construction and energy consultancy. The results of the initial investigations are used to inform the design of a temporary oven & build enclosure which is then tested by the use of specially written spreadsheets for cost and energy modelling. \n \nTest results cover various sizes of boats from twenty to fifty feet (6 to 15 metres) at curing temperatures of 50 and 80 C based on data from a leading resin supplier in the industry and the stated alternative times for ramp-up and curing periods. \n \nThe main conclusions (related to the manufacture of boats in the above range) are that in the short term it is cheaper to use additional energy for post-curing than to construct a more efficient build enclosure / oven where costs are being passed on to the customer and that it is difficult to combine an access structure for working on the mould with the enclosing structure of the temporary oven. \n \nBased on the spreadsheets developed by the author, graphs are provided as a ‘rule of thumb’ guide to power consumption and total costs for post-curing boats of various lengths. \n \nA detailed analysis of the spreadsheet results concludes that the key pointer is to find a practical way of fixing the insulation on the inside of a temporary structure in order to minimise the total mass to be heated. \n \nThe report touches on the short-term nature of individual project-based yacht manufacturing and observes that it is difficult to justify long-term investment in more efficient production spaces for post-curing until tax-efficient incentives, such as capital allowances for plant & machinery can be applied to the use of temporary ovens. \n \nIn the longer term, the report identifies the potential for further work on the development of a standard kit of parts for energy-efficient oven construction which could be erected and dismantled as required at minimum labour cost within a lightweight build enclosure. The incentive for this investment could be a radical shift in the real cost of energy – and a sea change in attitudes towards energy use and generation – over the next decade. \n \nMeanwhile, the boatbuilding industry appears to be on a plateau of efficiency for one-off post-cured products, based on the individual efforts of yacht manufacturers to deliver a quality product to their customers at a reasonable cost. \n