Join Date: Jun 2006
Location: San Diego
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Re: ps 31 water tank leak
The water tanks are made up of the hull and the inner liner with a lid.
Originally Pacific Seacraft tops were plywood. By 1989 they had switched to PVC. If the new Pacific Seacraft is making them out of fiberglass that is good to hear as the PVC ones have issues with sealing to fiberglass liner.
To attach the PVC tank lid Pacific Seacraft provided the following instructions:
1 Prefit PVC tank lid on hull liner tank flange making any adjustments necessary.
2. Prefasten lid with #8 x 1 inch counter-sink flat head sheet metal screws with finish washers making sure that there is a clearance hole for the screw shank in the lid. Screws are to be positioned at all corners and psaced on approx. 6 inch centers
3. Unscrew and release lid
4. Remove any residual mold release was from the hull liner by using interlux 202 fiberglass solvent wash or a soap and ammonia solution in way of the tank lid flanges.
5. Sand the liner tank flanges with 100 grit sandpaper.
6. Repeat procedure 4 cleaning up thoroughly so as not to contaminate the potable water tank.
7. sand the inside edges of the PVC tank lid to a width of appox 1 inch with 100 grit sandpaper
8 Apply sparingly a thin coating of Dow Corning ROS Prime Coat (or Eauivalent) to the sanded surface of the PVC lid and leave to dry for 15 minutes.
9. While Primer is drying run a continous beed of Dow Corning 999A Clear Silicone.
There may be more but that would be on the second page of fax which I don't have.
On my boat they did not apply the prime coat, so the tanks all leaked over time. I followed their instructions and the tanks still leak if over-filled.
Tanks lids made of fiberglass which would then bond with the fiberglass liner would be seem to be the ticket.
Crazy Fish, Crealock 37, Hull 207, 1989