B31 Fuel Tank Removal

[fiedlerwj]

Deck is up and I'm ready to start cutting tabs to remove the FG fuel tank from my '76 B31.

-Are there glass tabs on the forward side of the tank, closest to the forward deck bulkhead?
-Any other foam or bedding compounds that the tank is sitting on?
-Once all the tabs are cut, can the tank be pulled?
-Any other suggestions or historic postings for reference on this removal project?
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GIRLFRIEND PICTURES

[CaptPatrick]

Bill,

In most cases only the cast urethane foam & side tabs are all that hold the tank in place. Occasionally, Bertram also tabbed the two ends of the tank to the hull.

Find yourself a strip of steel about 2" wide & maybe 2' long, & about 1/8" thick. Local scrap yard should plenty laying around... Use that strip to plunge down around the tank & cut the foam loose. Use the tank wall as a guide and shoot all the way to the hull.

Most of the tanks have a lifting ring at each end. If you have access to either a fork lift or crane, loop onto the aft ring and apply a straight up lifting pull. Do this slowly & watch for movement of the whole boat. If the boat starts to move, STOP. Determine whats holding the tank and hull together, other than foam.

You should hear the foam under the tank cracking loose & see some movement of the tank. Once that is accomplished, do the same from the forward end.

At this point the tank should be free and both lifting rings can be bridled together and the tank lifted out.

In the absence of a fork lift or crane, you can build a strong back by fabricating 2 pieces of 2x4 & 1 piece of 2x6. Screw & glue the 3 pieces into an I-beam configuration. Add at each end a 4' piece of 2x6, perpendicular to the beam, to act as resting points on the gunnels. This will also spread the load. Use a come-along as your source of force.

The tank weighs about 200 lbs so you'll still need the forklift or crane to lift it from the boat.

If you're blocked on land, be sure that you have safety chains between your jack stands.

If you run into problems getting the tank loose there's another way to break it loose. I'll explain that later, if necessary...

Br,

Patrick

[fiedlerwj]

Patrick,

Thanks for the suggestions.

I can see a tab on the back side of the tank. Will be able to cut this tab by using great care not to cut into the hull or tank. Concern for me is the forward end of the tank. I have not gained good access (yet) to see if they tabbed the front side of the tank.

- Question - If the aft end of the tank was tabbed, was the front side tabbed also?

If so, I assume the only access would be to cut out the forward deck bulkhead behind the down step???

Regards,

Bill Fiedler
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Subaru leone

[CaptPatrick]

Bill,

If its tabbed aft, you can be sure it's tabbed forward also...

In this case you'll need to remove at least the lower portion of the fwd bulkhead in order the access the tabbing. Once having that access, you'll also have the advantage of using wedges under the tank to break it free.

I make a couple of wedges from 2x4 about 3' long with the taper on the 4" face. Make the taper about 12" long. Use a 3 lb machinist hammer to drive them in. Stay well outboard of the center drain race below the tank.

Here's a few images of the tank removal on Patrick Hancock's B31...

Br,

Patrick

[JP Dalik]

Capt Pat
Nice oval pipes

[CaptPatrick]

Thanks, JP... Just decided to be a bit different this time around.

Since glassing in exhaust tubes from the inside is real pain in the ass, I built composite flanges, dry fitted the tubes, slipped on the flanges to conform to the hull, & tacked them in place on the tubes.

Then removed the tubes and glassed the flanges on. When I was ready to install the tubes, I buttered up the hull side of the flanges wuth thickened epoxy and squashed 'em into place...



Br,

Patrick

[fiedlerwj]

Hello Patrick<

- Got my B31 tank out over the weekend
- On my '76 - No foam along the edges of the tank
- The tank was not tabbed on the forward end of the tank by the engine bulkhead
- Aft engine bulkhead had to be installed and glassed in before tank installation
- Used a cut off wheel on my Dremel tool, cut all tabs on three sides
- Used your suggestion to use cut 2 x 4 wedges on the aft end of the tank
- Had to work up to 4 x 4 wedges until the tank broke free
- Aft end was up almost 4" before breaking free forward
- Tank was held in place with a very hard compound
- Two thick beads were applied along the top of the raceway
- Very hard material
- Took some time to pound the tank free

- Now it's out and I need to review postings about intalling a new AL tank
- Looks like the original tank sat in water - bottom of the tank had water lines
- Was thinking about raising the raceway - eliminating the original tank's bottom shape
- Get it up and away from the bildge water .

Bill Fiedler
Forked River, NJ
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Yamaha Srx