Epoxy resin is an indispensable part of the boat building. Properly mixed and provided with the right accessories, designed this plastic unexpected capabilities. On the subject of plastics in yacht comes to mind first, of course, the symbol FRP.
One thinks of glass fiber reinforced polyester hulls, which once revolutionized boat building: could suddenly, inexpensive boats are made by reproduction in a once-made form and with a previously unknown technology, the lamination. Just went along with it to effect repair and Monti elaboration. Today the applications are many and not from the Marine indispensable. Yards, such as home builders are now working with plastic matter of course. They seal, strengthen, filling, laminating and profile.
For repairs and construction of individual structures, the Epoxy Resin The polyester, however, outranked. Include epoxy resins (such as polyester) to the heat-curing resins. After combining with a hardener, they heat up, are thick and form after the reaction, a solid material. Epoxies develop a high bending strength, they shrink a little and take little water. For this purpose they are excellent adhesive. In its individual components arise, for example, hulls from wood and resin (composite construction) with high strength and low weight.
By additives, the properties of epoxy adjusted specifically to the respective roles, so through his thick liquid powder to an adhesive with wood fibers or other filler to putty.
Important for the success of working with epoxy is the right mix of resin and hardener. It must be followed meticulously. It is resin and hardener in canisters of various sizes with metering pumps. A hub a hub resin plus hardener - and the mix is right. Otherwise, think you look at the three golden rules for processing: measure accurately, slowly stir thoroughly. Epoxy resins and their hardeners more can cause allergies. Rules for health protection are to be considered urgently. So go without eye protection and gloves to work. Contacts of resin and hardener with skin or eyes evoke irritation. When adding fillers and grinding must be a dust mask be worn. Elaborate extraction systems are not required, however. While evaporated and epoxy, but there are no solvents released such as the harmful styrene in the polyester.
Main problem in the use of wood in boat building is the dry rot. It is caused by high humidity, low light and low air exchange. Epoxy protects as a high build, or (diluted with some solvent, for example Eposeal 300 or SP 301) than in the wood penetrating sealer. To close an area completely, you take Epoxy masse best undiluted layer by layer and ensure that the necessary time interval. It should be "wet on tacky" to work, and must always follow the next layer only when you touch only on the previous remains a fingerprint. Only after the hardening the last layer is sanded and painted.
To amplify a supporting part, a wooden plank or similar, put fiberglass in the previously applied epoxy coating and soak it. It followed with additional layers of epoxy. The result is a plastic cover high abrasion resistance, can also absorb forces. This allows wooden decks or canopies to protect and enhance. The resin mixture is applied with a mohair roller, which must be well watered so they do not, the fabric apart. Between the application of the laminate and the last are epoxy should take five to six hours. The resin system is then set, but is not yet fully cured. Now you can still edit edges and overhangs with the blade. The last layer must be applied thick, may still be exposed to embed good fibers in the resin composition.
Epoxies adhere to most surfaces exceptionally well. Wood, metal and fiberglass are preparing this material, no problems. Apart from the mandatory background preparation and careful mixing of resin and hardener is eighth in bonding to the absorbency of the surface. It must always be enough resin left on the surface. On soft and porous wood is often a pre-priming necessary so that the resin does not penetrate too deep and the surface is dry once again. Also, addition of fillers is enough resin to secure the bond. These additives impart the resin also gap filling properties and the parts involved are compensated. There are many ways to bond with epoxy resin. Even fittings on deck of wood and fiberglass boats can be mounted so durable. Due to the good load distribution over the large area resin mixture attacking They often better than bolted connections.
Working with fillets
A special adhesive technique is preparing a fillet. With suitable fillers, such as microfibers, made of resin is a paste. It can be good for the manufacture of so-called fillet connections to use, that is, for example, bulkheads attached to the outer skin. The radius of the throat is important: It should be between three times to five times the thickness of the parts.
With the different additives you can make all kinds of epoxy resin filler. At about the repair of holes and cracks or even larger areas for profiling. To repair a surface or smooth, put the filler in addition to low-density adhesive powder filler powder until a useful purpose is achieved for the thick consistency. A classic application is the profiling of a keel or rudder, if such be improved by changing the profile shape, the properties are to sail. To do this, build templates that you drag over a large area of the coated filler mixture. After curing, final details are still corrected by sanding.
Laminating is the joining of reinforcing layers to form a laminate. In boat building known laminates of fibers and laminates of wood veneers. Both are easy to manufacture with epoxy. For example, you can count on this kind of a rudder blade. As the core of lightweight foam or wood will be consolidated. Register with enough resin to reinforcing fabric. It is important to prime the sanded surface with adhesive resin mixture and powder additive. For the actual lamination set yet added filler powder. The reinforcing fabric is at the core with staples or simply secured with tape to prevent slipping. Excess resin is removed prior to curing. After curing, sand the surface smooth and seal it with resin mixture. The final coating is done with undercoat and gloss paint.
Repair of GfK
Epoxy is particularly suitable for repair of fiberglass boats (GRP). Extensive damage can be laminated, or with only small ausgespachtelt reinforced resin mixture plus an appropriate filler. Damaged material cut out of the boat builders, as in round or oval shape and beveled at the edges. If the damaged tissue, is back-feeding. The choices include a resin-impregnated fabric or trimmed patch of a plastic plate. All other work done along the lines of fill step, or laminate. The repair of polyester with epoxy requires (besides the usual) no special treatment on the ground. Epoxy resin is cured polyester surfaces is not only "compatible", its adhesion to this material is rather better than that of polyester on polyester.
Epoxy in the hull construction
With so many advantages, one wonders why there are so few production boats made of epoxy resin. Given an "insider":
All the world the GRP construction has begun with a polyester for use of epoxy, the yards should now change their technology with this material to build otherwise it is not the higher cost of the resin, which prevents the mass production the contrary....: Epoxy hulls are even cheaper, because less resin is needed. The hulls are not only solid, but also easier.
It's still managed to any producer to develop a UV-stable epoxy gelcoat. Individual buildings will like the car a final coat of polyurethane varnish. This is for the series too expensive. And a gel coat of polyester is a trade off that is at best at can use ships which are sailing again after each removed from the water.
It is still a lot to do to epoxy "serial development" to make. For many small applications and the individual buildings but the resin is already perfect.