Started the project 4 weeks ago, completed this week. Frustrating to miss all that time on the water, but was interesting learning the design strategies behind the tank, bulkhead, deck construction, etc. I worked with a local fiberglass shop here in the SF Bay Area to complete the project together. I should have taken better photos along the way, but feel free to message me if you have any questions. Hope this is helpful for others who are planning/undertaking a similar project.
Measured the cut-out to stay inside of the stringers. Mine was right at 30" across. You have some flexibility on the length, depending on how tight you want to get to the door and battery compartment.
Lifting the tank out, can begin to see the amount of fuel and seawater that has accumulated in the bulkhead. My tank corrosion was on the front port side corner, right under fuel fill hose.
Pumped out a good 10-12 gallons of fuel + seawater mixture.
All the foam removed. Did not put foam back in. Also, drilled 2 drain holes from the rear of the bulkhead (on either side of the pipe) into the bilge, so any water can drain out in the event of intrusion. My bilge is generally pretty dry, so I'm willing to take on the small risk of water potentially occasionally backwashing from the bilge into the fuel tank bulkhead.
New tank, identical general specs to the original 150 gallon FM tank, with a few additions. Welded on some "feet" to prevent tank from sitting directly on the bottom of the compartment, and to raise tank back to roughly previous height (since I removed about 1" of foam all around). Also lined the feet with viton to prevent the aluminum from rubbing directly on the fiberglass.
Probably overkill, but heavily reinforced the deck with 4 cross beams into the stringers. I'm 240 lbs and jumped on the beams repeatedly - was very stout. Make sure to 1) line up the beams so that they don't block any hatch/deck plate access, and 2) get your green ground wire all screwed in, and hoses clamped before closing up the deck.
Laid the original cut-out back on, and ground the edges to prep for glassing. Sorry I don't have any photos of the glassing, as I left that work for the shop.
Color-matched and rolled on fresh nonskid (which was long overdue).
Hatches and deck plates back on.
One other thought:
-Not sure about other folks, but my original tank was pitched forward/downward. The front of the tank was about 1" lower from the deck than the back of the tank. After I removed all the foam, it exacerbated the pitch. My new tank is now about 2" lower at the front vs the back. I decided to just leave it that way, but in retrospect I probably should have evened out the height a bit because I have now effectively reduced by fuel tank capacity (since I will "overfill" the front when there is still space in the rear of the tank). During my first fill-up at the gas station on the trailer, my 150 gallon tank only took 132 gallons before it started spitting.
As I said, feel free to message me if I can help answer any questions. Good luck!
Measured the cut-out to stay inside of the stringers. Mine was right at 30" across. You have some flexibility on the length, depending on how tight you want to get to the door and battery compartment.
Lifting the tank out, can begin to see the amount of fuel and seawater that has accumulated in the bulkhead. My tank corrosion was on the front port side corner, right under fuel fill hose.
Pumped out a good 10-12 gallons of fuel + seawater mixture.
All the foam removed. Did not put foam back in. Also, drilled 2 drain holes from the rear of the bulkhead (on either side of the pipe) into the bilge, so any water can drain out in the event of intrusion. My bilge is generally pretty dry, so I'm willing to take on the small risk of water potentially occasionally backwashing from the bilge into the fuel tank bulkhead.
New tank, identical general specs to the original 150 gallon FM tank, with a few additions. Welded on some "feet" to prevent tank from sitting directly on the bottom of the compartment, and to raise tank back to roughly previous height (since I removed about 1" of foam all around). Also lined the feet with viton to prevent the aluminum from rubbing directly on the fiberglass.
Probably overkill, but heavily reinforced the deck with 4 cross beams into the stringers. I'm 240 lbs and jumped on the beams repeatedly - was very stout. Make sure to 1) line up the beams so that they don't block any hatch/deck plate access, and 2) get your green ground wire all screwed in, and hoses clamped before closing up the deck.
Laid the original cut-out back on, and ground the edges to prep for glassing. Sorry I don't have any photos of the glassing, as I left that work for the shop.
Color-matched and rolled on fresh nonskid (which was long overdue).
Hatches and deck plates back on.
One other thought:
-Not sure about other folks, but my original tank was pitched forward/downward. The front of the tank was about 1" lower from the deck than the back of the tank. After I removed all the foam, it exacerbated the pitch. My new tank is now about 2" lower at the front vs the back. I decided to just leave it that way, but in retrospect I probably should have evened out the height a bit because I have now effectively reduced by fuel tank capacity (since I will "overfill" the front when there is still space in the rear of the tank). During my first fill-up at the gas station on the trailer, my 150 gallon tank only took 132 gallons before it started spitting.
As I said, feel free to message me if I can help answer any questions. Good luck!
