Once the Kilz primer had time to dry, I installed the walls. The walls are made up of 2 layers of
3/4" plywood. The layers were installed one at a time, using 1.5" screws spaced 1" apart, down the
length of each post. A standard sheet of plywood is not large enough to cover the entire area of the
tank. So several pieces were used for each layer. When installing the second layer, I installed
them in a "mirror image" fashion. This ensured that all seams on the first layer, were cover by a
solid piece of wood on the second. In addition to the screws, liquid nails was used between all
pieces of plywood, and in all seams. My goal was to make these walls as much of solid piece as
possible.
Next came the most time consuming process of the project. Fiber glassing. I had made some small repairs
to watercraft in the past, but this would be my first full scale fiberglass project. I called US
Composites for some advice on what to use and how to use it. They set me up with a full roll of 36" wide
7 oz fiberglass cloth, a roll of 6" 10 oz fiberglass corner cloth, several gallons of resin and hardener,
and all they necessary aluminum rollers and tools. I explained what I was doing to them, and they gave me
lots of useful tips and information. They sent me a product called cabosil, which is used to thicken the
fiberglass resin turning it into a paste of putty. This would be used as a filler for all of the corners,
gaps, and screw holes. I also had them send me 25 graduated mixing containers in various sizes, as I knew
my wife would flip if I ruined every piece of tupper ware she owned!!!
A few days later, all of my materials arrived and I went at it. The first step was to fill all of the
gaps, holes and seams. I mixed up approximately 16 ounces of resin, and added cabosil until it was the
consistency of peanut butter. I didn't want to mix too much at one time, as the resin sets and begins to
harden (approx. 15 min) fairly quickly. I used putty knives to fill in all imperfections, and then let it
cure. 24 hours later, I would sand everything down, and do it again until it was perfect. If remember
correctly, I had to do this 4 times. When I finished this process, I began laying the first layer of
corner tape. I would brush/roll down a thing layer of resin first, and allow it to become tacky. Then I
folded the 6" corner tape into a 90 degree angle (3" per side) and apply it to the corners of the tank. I
used one piece all around the bottom of the tank. When I would come to another wall and had to turn, I
would cut the bottom portion of the tape at a 45 degree angle, and fold it over. This allowed me to make
the 90 degree turns without having to use another piece of fiberglass. I glassed all corners (vertical
and horizontal) and allowed it to cure. I used the aluminum rollers to smooth the glass, and then applied
another "light" layer of resin. It should be noted that the strength is not in the resin, it is in the
fiberglass itself. You only want to use enough resin on the first layer to hold the glass in place, and
wet the back side. Then after laying the glass, use only enough resin to wet the cloth thoroughly.
After this first layer in the corners, I learned a valuable lesson. Fiber glassing is not nearly as easy
I had once thought. Fiberglass cloth becomes quite slipper/slimy when wet with resin. Using the rollers
to effectively smooth out all bubble and creases was an art. Too much pressure and the 15 minutes work is
shot, as the glass will slip out of place. Too little, and you'll have bubbles/gaps between the walls and
the fiberglass.