Stratification: “contact” or infusion ?
Let’s start by some theorical bases
The infusion
is a stratification technique from aeronautics and used in boating for a few years. On the one hand, it allows better control of the resin dosage and the regularity of the application. It is therefore possible to make very light pieces of equal strength compared to a piece traditionaly made. Second significant advantage, the operator making the piece is much less in contact with the polyester resin and therefore much less exposed to styrenes. This aspect of the subject is important to preserve the health of our technicians, and to respect the future standards of the boating industry which regulate the exposure rate of the employees of the sector to toxic products. Finally, this technique brings a significant time saving.
The method consists in setting up and assembling dry the different layers of fiber glass, foam, or wood depending on the piece beeing made. The whole layers are then covered with a sealed plastic film or a counter-mold. We then only need to inject the resin through an intake, while aspiring it from an outake through a vacuum pump. Once the resin is distributed in all the strata of the treated parts, it needs to dry, and we will then be ready to unmould and get rid of the consumables … Easier to write than to realize on a 15m hull !
“Contact” Stratification
is the technique used by our shipyards since its beginnings. The operator applies a first layer of liquid polyester resin, usually by spray. He then deposited a first layer of fiberglass, which he will cover with polyester resin. Finally, he will have to make sure that the resin penetrates well the tissue by soaking it manually using a roller. This manipulation is as much to imbibe the fiberglass as to chase the air present between the different layers. The operation is then repeated as many times as necessary to obtain the desired number of layers.
We always use this technique for the construction of the AMEL 64 and AMEL 55 hulls and decks, as well as for the first layers on the AMEL 50 hull.
