PDF Publication Title:
Text from PDF Page: 024
4.1.2 Laminating a rudder half The laminate in this example is the right half of a rudder blade for a small catamaran. The method demonstrated here is a variation of the previous method. This laminate incorpo- rates core material and the mold is enclosed in a vacuum bag envelope rather than relying on the mold as half the envelope. The laminate schedule consists of an epoxy gelcoat, one layer of 15 oz biaxial fiberglass fab- ric, a layer of core materials and a second layer of 15 oz biaxial fiberglass. The adhesive is WEST SYSTEM 105 Resin and 206 Slow Hardener. The core material varies depending on its position in the rudder. Foam core is used in the lower blade area. Thinner material is used in the thinner trailing edge. Thicker material is used in the center and leading edge. Solid spruce and end grain balsa core are used in the more highly stressed upper area and where the pivot pin passes through the blade. When using solid materials like wood veneers or cores, it is important to avoid air entrap- ment under the material. If the edges of the core contact the mold surface before the center, when vacuum pressure is applied, a pocket of air may become trapped under the core. In many applications, the core or veneer is perforated to allow air to escape. In the following application, the core is carefully bedded in a layer of thickened epoxy which holds the core in position and eliminates voids under the core. The thickened epoxy also conforms to the uneven space between the flat cores and the curved mold surface. See Section 4.2.3. A strong mold is required when using a vacuum bag envelope. This method of vacuum bag- ging can deform or collapse a weak mold. A relatively flat mold, such as the used here, is more suited to the vacuum bag envelope. Vacuum Bagging Applications 21 1. Prepare the materials to be laminated. Cut fabrics, ve- neers, and core materials to shape and place them in a convenient area for wet-out or placement in the mold. Cut the release fabric, perforated film (if required), breather material and vacuum bag envelope to size, then roll or fold them and place them in a convenient loca- tion. Apply the appropriate mold release to the mold surface and the shelf to act as a release agent. Follow the manu- facturers directions for applying the mold release. 2. Apply a coat of gelcoat to the mold and allow it to cure. The gelcoat is a mixture of resin/hardener and white pigment, thickened slightly with 406 Colloidal Sil- ica. Wash the surface of the cured gelcoat with water and an abrasive pad to remove any amine blush that may have formed on the cured surface. Dry the surface thoroughly with clean paper towels. See Section 5.4.1, Surface prepa- ration—cured epoxy. Sand bumps or rough areas to as- sure the laminate will lie flat in the mold. 4PDF Image | Vacuum Bagging Techniques 002150
PDF Search Title:
Vacuum Bagging Techniques 002150Original File Name Searched:
VacuumBag-7th-Ed.pdfDIY PDF Search: Google It | Yahoo | Bing
5,000 BF Shipping Container Lumber Dry Kiln For Quality Lumber The 5,000 BF container kiln consists of one 40 foot high-cube aluminum shipping container... More Info
Shipping Container Lumber Dry Kilns by Global Energy Global Energy designed and developed the container kiln back in 1991. The purpose is to give access to portable sawmill owners, furniture makers, and small business the value added profit of dry kiln lumber and quality hardwoods... More Info
Vacuum Kiln Conversion Kit for Lumber and Wood Dry Kilns Convert your existing conventional dry kiln into a fast drying vacuum kiln. Similar to vacuum bagging in the boat building and aircraft industry, we have come up with a proprietary process which allows you to build a very simple vacuum kiln at a fraction of the price, and without the intensive conventional metal chamber structure... More Info
Vacuum Pump Cart System for Bagging Clamping Wood Drying and more Vacuum Cart with 2HP Pump and Dual Pistons with multiple multiplex vacuum ports and liquid reservoir... More Info
Vacuum Bagging Basics Vacuum bagging is a method of clamping, which has traditionally been used in the composites industry, but can also be used for vacuum drying materials, including wood products... More Info
CONTACT TEL: 608-238-6001 Email: greg@globalmicroturbine.com (Standard Web Page)