Installing a Fiberglass Windshield Cap10/2005
There are three approaches to fiberglassing the front window sections on a 31 Bertram: 1 - Leave the aluminum frames in place and install a fiberglass cap over the frames ("Kahuna") The fiberglass cap, available through Richard Kidd at Allied Richard Bertram Marine Group is a one piece unit about 1/4" in thickness and generally fits the dimensions of the B31. It is bonded over the aluminum frame and glassed in at the bottom joint. The top joint is filleted with epoxy, but it is not necessary to add fiberglass. Several considerations that must be made in deciding to take this approach include: 1 - The aluminum frame and windows will remain exposed from the interior of the cabin. How is that look going to be addressed? As I move through the installation, you will see my solutions and recommendations. Because of the different dimensions of every B31, most after market fiberglass items must be trimmed, added to, and otherwise modified to make a good fit on a given B31. The windshield cap will not be an exact fit so be prepared to make the necessary modifications. Since I work alone in most cases, I also elected to bisect the cap into two halves. This will make it easier to wrestle with and not add an appreciable amount of work by having an additional joint to glass in. I replaced the safety glass with 1/4" clear acrylic sheet. On both of them & on the side windows, I painted the outside surfaces with Rustoleum Egg Shell White paint for plastic. (Real close match to the Bertram gelcoat color inside Ron's boat.) That way the interior view becomes another clean surface of the correct color. (Ron isn't, at least at this point, going to do any cutrain or fabric cover inside.) I don't like the idea of having large void spaces between the cap and the windows so I've built up the spaces with 1/4" plywood to bring them closer to flush with the frames. The bonding technique will be with 3M 5200 and countersunk screws. Because of the curve on the corner windows, I built the plywood panels with 3/4" strips using a pair of old acrylic windows as a form. Most individuals will not have the luxury of old windows laying around so there are two approches to building these panels: 1 - Apply the strips directly on the windows, one strip at a time. This will be more time consuming and the work will be uncomfortable without the aid of scafolding. On the cap I have the lower corners were radiused, for hat stupid reason I have no idea, and both sides were short and not at the same angle as Ron's frames. I added fiberglass plate to both ends and a strip in the center to decrease the gap between the two halves. This work was done with polyester resin. 
The bonding of the acrylic & plywood into the center windows was done with acrylic caulk which has a faster cure time and easier clean up than other available caulks or adhesives. Since the windows are getting capped, high adhesion isn't necessary as would be the case if the windows were exposed. 
For added security of the window insets, I drilled multiple holes into the frame at a steep angle and drove in glazing pins, (note on the image above the 5200 dabs around the window on the left). The plywood was then sealed to exclude any potential for moisture intrusion before the cap is installed. Below, the center windows are back in place, locked down with a pair of screws in the lower main frame and caulked over with 5200, again keeping water out prior to the cap installation. 
Below you can see that the addition of the plywood brings the window area closely into a flush plane with the main frame. 
This will yield more bonding surface to the cap and not have a "springy" hollow area, as would be the case without the plywood. 
The rattle can spray paint will need at least 2 or 3 coats to have a consistant appearance from the inside. 
Below, I'm making up the plywood strip fillers for the corner windows. The first on I did was done over the exterior surface of the window and it works OK, but was a little stiff. The second one was done from the inside of the window making it far easier and quicker to stack in the strips, apply the fiberglass tape, and gave me a more flexible panel. Since these were done from another boat's windows, they'll have to scribed and fitted to Ron's windows. 
I'll continue with the installation next week, so stay tuned for more images and techniques... Br, Patrick For additional information, please contact: Capt Patrick McCrary 1 Bill Holmsey Fiberglass Windshield Kit Holmesy Company 960 South Old Dixie Highway, Jupiter, FL 33458 (561) 746-3476 |
