Securing aluminum fuel tank in 1973 19-6

[John G]

I know this topic has been covered over and over, but was there ever a final consensus on the best method to secure a new aluminum tank under the deck?  I'm on the rebuild and the deck is almost ready to be installed, the tank coffin is gone and the hull is wide open front to back - so I've got options. I guess what I'm after is what material should touch the tank top and bottom.  I plan on leaving it all wide open for air flow.

[boatnamesue]

........but was there ever a final consensus on the best method to secure a new aluminum tank under the deck?

Final consensus....haha.  I used the modified Pascoe method to secure tank when I replaced it 4 years ago.  Just recently pulled the fuel hatch for a console rebuild and the tank is solid...hasn't budged an inch.  Can't speak about other methods, but this one I can recommend.

[Capt. Bob]

I guess what I'm after is what material should touch the tank top and bottom.

In my personal experience, 3M 5200.

Use it as both an insulator and bonding agent to whatever material you choose to support and secure the tank in the coffin.

[John G]

So the Pascoe method it will be, but I no longer have a tank coffin.  Under my deck is wide open bow to stern.  The old coffin on this '73 wasn't really doing much anyway.  Just a piece of rotted plywood on the bottom and the ends barely covered with a thin plywood.  It wasn't sealed up against the deck at all.  I would say it was more of a "platform".  Any reason to put the coffin bottom back in?  I was hoping to just glass in a few tabs along bottom of the hull and then 5200 the pvc strip on the tank to them.  I guess I could glass in a new platform bottom with a piece of coosa (where the plywood was) so that the pvc strips on the tank have something to sit on.  The new tank isn't as wide as the old, so I've got plenty of space between the stringers. 

[Fish Head]

I did the same thing yanked out all the old rotted plywood and replaced with new. From the looks of the plywood it was not glassed as nice as the old deck was. Maybe they brushed some resin on it? I  pre epoxy resin soaked the plywood this time. Than 2 layers csm and 2 layers 1708. Had extra material figured might as well use it. Solid as concrete. I did notice that there was “factory” stand offs for the base plywood to sit on that put the base at a small angle dipping forward in hull in relation to the stringers. . Not sure if this factory setting is necessary but I kept it figuring why mess with it and screw something up I don’t understand. In my galllery is a pic of my tank. I had oversized brackets added to my tank just for extra peace of mind and did a modified Pascoe method. Cheers

[Capt. Bob]

The plywood platform allows water to pass (to some degree) from bow to stern along the keel while keeping the tank bottom elevated and provide a table top for the tank to rest on.