Gel Coating has been used for forming composite structures since ancient times. Although the gel coating method is very primitive, it offers the advantage of being able to deal widely with different production volumes and product sizes because the molds used are inexpensive and facility costs are low. On the other hand, gel coating work itself relies on human skills, which means that the finish differs according to the operator carrying out the work, the quality of the product differs among parts depending on the ease of forming. Hence highly specialized control technique and the tradition of skill are required to ensure the consistent stability of product quality. Generally, it needs more than 25 years of training and practice, as well as relentless efforts and an instinctive sense of molding to master the art of gel coating. However, there are in fact very few people who can be called experts of the technique in Japan. For this reason, the tradition of molding techniques needs to be carried on as quickly as possible.
It is considered that the experiment, seemingly a new and only attempt in Japan, quantified techniques that are not visibly apparent and considered to be tacit knowledge. Therefore, in this study, motion analysis experiment of gel coating experts by MAC 3D System at a sampling rate of 60 Hz was conducted to obtain objective data on an expert applier’s skills (the default value) with compared to the non-expert one. Furthermore, dimensional stability measurements were made, and an investigation of the correlation to an expert’s application techniques was conducted in order to pass the suitable training and communicating technical skills to advanced management engineering and inexperienced appliers.
It is found that the movement of an expert applier’s lower body had a different motion compared with a non-expert applier. The expert’s centroid moved smoothly and his motion tended to be constant. On the other hand, the non-expert’s motion was awkward at several points and his motion didn’t have the same tendencies as the expert.