Fuel Tank replacement

[msigur]

I own a 1993 Proline 20' Classic. Just recently my fuel tank has begun to leak so I am going to replace the fuel tank by cutting the fiberglass deck. Once I remove the tank I was going to place 5754 grade 1/4" thick aluminum plate over the deck and attach the plate to the fiberglass stringers.

I am looking for some advise regarding using 5754 marine grade vs going back to fiberglass.

[Cheechako]

Your fiberglass tank leaked? Aluminum has it's issues for sure. You could repair a fiberglass tank.

[msigur]

The tank is metal.

[Cheechako]

Oh, you're asking about using aluminum plate to replace the cut out deck....
Hmmm, I guess why not? How big an area? You may be able to use thinner than 1/4" if the span isn't too wide.

Or you can just mod the fiberglass you cut out (Cut carefully) with an Aluminum or fiberglass flat bar lip all around and bolt it back in.

Untreated aluminum plate will start turning things like your knee etc you put on it grey from the surface oxide residue. If you are in the salt water it will get fairly ugly compared with the fiberglass.

[msigur]

The cutout will be about 3' x 7'. I was going to put a 4'x8' aluminum plate down and was going to bevel the plate edges and corners. Then will acid wash the plate so it could be primed and use marine tuff coat to match the color of the original deck. I was also going to make cutout in the plate and make access panels as well.

I believe 5754 marine aluminum is the best marine aluminum they make.

To re-fiberglass the boat deck and replace the fuel tank came with a price tag of $3500. I feel I could do this for about $1500.