
9610 Commonwealth Ave., Jacksonville, FL 32220
3) CD 27 - Biaxial Cloth Laminate Schedule to Aft Locker
January 5, 2024
A week into the New Year, I returned to work on the aft locker - time to build up the laminate with the application of new fiberglass. The replacement chainplate / knee system for the backstay on this Cape Dory 27 would be a combination of a new laminate schedule of 1708 biaxial cloth and G-10 (an epoxy resin and fiberglass plate that is laid up under considerable pressure, producing an extremely high-strength material). My approach for replacing this backstay rigging support assembly is to reinforce the existing laminate with three layers of 1708 biaxial cloth, and in the process bond the deck to the hull. Additionally, a G-10 backing plate will be used to secure the pad-eye to the deck - the pad-eye will accept the backstay's turnbuckle. Finally, I will glass in G-10 knees, one on each side of the backing plate, and securely glassed to the interior of the stern.
To get started, I thoroughly wiped the surfaces down with acetone, removing all contaminates and generally cleaning up and removing the detritus leftover from the prep sanding. With the surface clean and ready to accept new material, I used a sheet of plastic to template the three individual sheets of 1708 cloth. Using a Sharpie marker, I traced three separate rectangular shapes with each roughly 2" smaller in width and height than the previous. I progressively cut these to their exact shapes and applied them to the cloth so that I could then replicate them in actual 1708 biaxial material.
With the three piece of fiberglass cut and ready, I mixed a good amount of epoxy resin (using West System in all my work) and thickened it with a combination of 406 colloidal silica and 404 high-density filler. With the thickened resin ready, I then wet out the surface with "neat" epoxy (not thickened), and then applied the thickened epoxy mixture. I used a squeegee to press the thickened epoxy into the remaining shallows and dips - the goal was to achieve a decent fillet at the deck-to-hull connection as well as create a fairly planer surface for the new fiberglass cloth.
With the aft locker work area filled to a "fairly-fair" surface, I wet out the smaller of the three piece of 1708 biaxial cloth with epoxy resin, using a scrap piece of cardboard covered with plastic, rolled it up and carried it over to the work surface and unrolled it. I took care in aligning it in the center of the work surface, wrapping it from the underside of the deck and down onto the hull. I repeated this process with the other two progressively larger pieces of cloth, and finished things off with the application of peel ply. The peel ply will reduce the need for sanding for future laminate work as it moves the amine blush (an epoxy resin contaminate) to the surface of the peel ply and discarded with the removal of the peel ply after the epoxy cures. Having done all I could in the aft locker, I went below and focused on removal of the port and starboard ceiling strips. The screw heads were small, old, crusty....and took some time, but I finally was able to remove all screws. With the screws removed, the ceiling strips were free to be collected, labeled and organized, and neatly stored in the v-berth to again beautify the salon once the lowers and upper chainplate/knee assemblies have been replaced, both port and starboard.
Total Time: 4.5 Hrs


