How to remove foamed in place gas tank

[doug hess]

The 70 gallon aluminum gas tank on my 1988 Ragazza 25 has to be removed for maintenance and inspection. The 1" to 2" space on all four sides is filled with "foam in place" material. Does anyone know the best way to get this material out and free up the tank.

The 24" wide tank must be rotated 90 degrees on a fore-aft axis to clear the 23" wide hatch opening!

Doug

[Donzi Customer Service]

The best way to remove the foamed in fuel tank is to cut the foam around the tank with a carpenters saw. Then take something solid, loop a rope around it and stick it through the fuel sender hole. Hook a come-a-long to the rope and put some tension on the tank, then every hour or so and give the come-a-long another crank. The tank will eventually break free.

[Robert Geoghegan]

Doug,
The way I removed the foam when restoring my 28' Magnum was to use a single claw hammer and chip away "tennis ball" size chuncks. It took alot of chipping due to the boat having two 80 gallon tanks and one 100 gallon tank.
Someone suggested that I use acetone to dissolve the foam but after spending money on several gallons, I found this did not work.
Good Luck!
BOB

[BigGrizzly]

Jr. the Ragazza is a Donzi made im the late 1980's. However DCS guys will help if they can or point you in the right direction if they can.

Randy

[Rob]

I have only removed one tank, but so far I agree with what has been said. I used a saw to release the tank from the foam on the sides, and then cut along the stringers so I could remove the foam entirely. However at this point it is still stuck to the foam on the bottom, and that represents as much if not more surface area than do the sides (on my tank anyway). The bottom line is that it is even after you cut away the sides, it is still pretty will glued down. I used a pry bar (very carefully, and with a small piece of wood to protect the tank) to move the tank back and forth in the space I created until it broke free. I expect I spent more than 2 hours doing this, so patience is important. The come-along idea the Donzi folks described is pretty clever, I would just make sure you apply the pressure slowly and cut out all of the foam on the side opposite of the fill so you don't put pressure on the bulkhead between the stringers as the tank comes up on one side and not the other.

[doug hess]

Success, Doug's tank is out thanks for the many good comments and suggestions in the replies to my inquiry. They helped keep me on the right track. Sorry for the delay in responding, but working outside in a New York area boatyard in January is not ideal. In case it might be of help to other here is how it was done.

My Ragazza there is no direct vertical access to the 1" foam in the gap between the tank and compartment wall because the deck/hatch opening extends over that space. How to remove the 17" to 22" deep foam was a real challenge.

The key was to rout out the foam using an electric hand drill with a 5/8" wood brace type bit that has wide open flutes. With the bit mounted on a 15" drill bit extension I was able to rout out the foam down to the inside surface of the hull. The pointed screw tip of the bit was ground off so that it would not dig into the inside hull surface.

By drilling multiple adjacent holes in the foam, then applying side pressure on the drill was able to route out an areas between adjacent holes while also keeping the bit from the contacting the tank side. Foam debris was removed with a shop vac using kluged anteater nozzles.

After removing the foam, rather than applying a vertical force to lift the tank, I pried sideways against the top side edges of of the tank using pieces of 3" angle iron as pads to distribute the force and it broke loose.

The aluminum tank is mildly pitted but is still usable. To clean the tank surface I am using a Taiwan sand blasting nozzle/hose kit ($19 at Odd Lot) with beach sand that is working great. Next the tank will be coated with a two part industrial epoxy mastic coating.

Many of the Donzi tanks, including mine, were made by RDS Manufacturing in Perry, Florida, phone 850-584-6898. They still have the original drawings and good prices.

Thanks again to everyone for their great help.

Doug Hess

[Forrest]

That's good to know. Perry is 45 miles southeast of Tallahassee. I wonder if they ever built any gas tanks for the Classic models? I'll have to give them a call and find out.

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Forrest

[This message has been edited by Forrest (edited 02-14-2001).]