Restoration of a 1999 C-Dory 22 Cruiser

[pcg]

[pcg]

[thataway]

As long as the aluminum fuel tanks are not held against saturated salt water foam, they will last many years. (assuming appropriate alloys) There are a number of salt water resistant aluminum alloy; 5052 has many excellent properties for boat building. 6061 and 6963 are also used frequently in boat construction. Many commercial boats are left "raw"--uncoated and do very well.

The Aluminum tank ideally should be washed, etched, and then epoxy (coal tar) coated. It should be laid on fiberglass or plastic strips which will allow any water to run freely clear from under the tank. 5200 is often used to "adhere" the tank to the plastic strips--and the strips to the fiberglass hull. Never use a "rubber" which has carbon in it to either "protect" the tank from chafe, or hold it in place. There are silicon "rubbers" which will do far better. The boats originally had :"cleats" screwed into the deck to hold the tank in place. By 2006 the factory had finally woken up to the better method of glassing strips in place.

I would remove the Bondo--then lay in layers of glass mat to fill the "keel" void--and make this water tight. Polyester or vinyl ester resin should be fine in this area. You don't really need the structural strength of roving or cloth. You only need the thickness. You could use polyester filler, but this often suffers the fate of "Bondo"...eventually. There may be some flexing in this area, and that is why I would suggest the mat. When you re-mount the strip--you can use 5200, instead of the ubiquitous sealants C Dory used during this time.

[starcrafttom]