expected life of gas tank?

[JACK ANDERSON]

Hey Guys,
I got a 1972 16 classic last year and I've been reading the registry for a couple months now and I'm seeing more talk then I would like about bad gas tanks. Do you just wait to smile gas or can something better be done? looks like a petty big job taking the boat apart

[Rich]

Jack,
If you have the old "terne plate" fuel tank, then now is the time to get that thing out. Terne is lead/tin coated steel. They are not even legal anymore. My '66 2+3 had one and I couldn't get insurance until I changed it. Yes, it's a big job but reducing the potential danger is worth the effort. If your tank is aluminum and your in salt water, the potential for a leak is also pretty good. Good Luck

[bigman]

Jack, I got a 18' 68. Found out I had to replace the tank when I found 2" of gas in my bilge. It is a pretty big job,have to split the boat (climb inside and cut some straps) lift it apart to get at it. Its kind of labor intense, but you can do it. On my boat taking it apart was the hard part. The top of my boat was a little heavier than I thought. Another set of hands sure helps.Goodluck,bigman

[rayjay]

Is there a list of gas tank types by year and model or hull numbers? For example, I am starting with an '87 22' Classic hull. Do I possibly have a tank that I should be thinking of changing out now even if it is not showing any signs of leaking?

rayjay

[mattyboy]

i think in 72-73 they went to alum from steel cause foamed in tanks rotted when trapped in moisture( water and gas)
then they went poly from alum cause foam ate alum.

your nose i s your best tool I could smell my tank and has you see on the boards many older classics are now being re-tanked the steel tanks won't last forever but 30-40 years is a good run!
and you have seen some mid 80's boats that have galavanic corrosion
the best tip is check the bilge out every time before starting, tanks aren't the only thing that leak, i had a crack in the fuel filter canister and had a bilge full of fuel Thank God I check everytime.


Matty

[Donzigo]

I think I can speak to this issue. I've replaced two tanks with my own hands, as many others on this board have also done. It makes the work very personal. The two boats were Dennis Bosch's (used to be ine) 1987 Z-25 and my current boat, the 1989 Z-33, replaced just a few monthes ago. In the late 80's, Donzi used a manufacturer of tanks from Perry, Florida (can't remember the name). I have heard on more than one occasion that the aluminum was slightly less thick than necessary. Those tanks are painted grey and have a tag close to the fill elbow or sender. The way that the plant installed was to place the tanks on strips of neoprene rubber and fill the sides and bottom with foam. Below the tank there is a plastic pvc pipe going from front to back to shuttle water through the compartment, which is supposed to be completed sealed and impurvious to water intrusion with the foam. But, what happened to both of my tanks is that over the years, water did find it's way to the bottom of the compartment and it just sat there corroding the tank. The corrosion looks like tiny B-B pellet dings on the bottom of the tank. You can't see it until you remove the tank. They don't ooze gas until they fail. Then, if the pipe is broken or back of the compartment is cracked, the gas goes to the engine room. If not, there is a faint smell of fuel present coming from the fuel compartment. When replacing, one can disasemble the boat or cut the fuel tank out with a saw's-all. I have done it both ways. My latest was the saw's all. I pumped/drained all the fuel out with a small hand pump from ACE hardware ($12.00), then took the sender off, sweezed in an entire bottle of JOY, sprayed the inside through the sender with water, lot's of it, then pumped that out , then taped a shop vac to the fill elbow and let it pump air into the tank for aobout 30 minutes, which escaped throuhg the sender hole. I then made my first entrance by drilling into the tank, then again several times, side by side, connecting the drill holes, so that my saw's all could get inside to cut. I was very frightened of this first dilling for fear of explosion. My tank builder showed me that aluminum doesn't cause sparks when drilled. Anyway, I sawed out large pieces of the tank little by little. When I looked inside, I thought, it looked great, and maybe I was doing something stupid. Not until I got the tank out did I see the bottom corrosion, and man, was it ever corroded. The late 80's Z-boats had a hatch built in the bottom of the floor; but, it wasn't big enough for the tanks to be taken out or put back in. So, in both cases, the my tanks were made smaller than the factory ones. I made the Z-33 tank 140 gallons, instead of the 200 it came with. DRS, here in St. Pete has built hundreds of them. He made the exit nipples much larger than original. Also, Derek painted it white (very important to paint the tank to revent future corrosion). He put large 10" x 10" flanges on each corner. Each flange has two bolt holes. I installed the tank on top of 1/2 inch neprene rubber, twice as thick as original, from Goodyear Rubber, here in St. Pete. Then, I through bolted eight bolts, two at eah corner, through the main stringers, with 5200 to seal the holes, putting nuts & washers on each side of the bolt at the tank and each side of the stringer, thus holding the tank with pressure from any direction. I also made the decision to delete the foam and the pipe underneath.

Many of the board members would strongly disagree with my decisions to through-bolt to my main stringers, delete the pipe below, and delete the foam. I must admit, I wrestled with those decisions for many weeks. I talked to many boat buiders, race teams and others whose opinions I respected. And, I will challenge anyone amoung you, who are sure to chastise me (this board ain't for the faint of heart or weak of conviction), to take a look at my work before judging me for it. The mechanical work is without flaw. You could eat breakfat in my fuel compartment, it's so clean. I beleive, (with prejudice), that the installation is strong, corrosion resistant (although, nothing stops mother earth, she will reclaim everything, including us), and will serve the future owners, (my sons), long after my ashes are sprinkled out at Marker 19, off of St. Petersburg.

Here are my conclusions:
1.Tanks need to breath and drain water to the back.
2.Boat builders use foam because it is cheap and fast to install.
3.I have had the tank for monthes and I've checked it often, it's fine.
4.I know water goes through the fuel compartment. Better than knowing that it will seep to the bottom and be there slowly corroding my tank each day
5. Stringers are very thick, are strong and will easily withstand the pressure put on them. Heck, the foam puts pressure on them too.

Here's my personal conclusion: Fuel tanks have a life of 10 years. Can they and do they last longer? - perhaps. If I buy a boat older than 10 years, I'm replacing the fuel tank. Boats burn in less than 5 minutes. My life is worth a new tank, if for nothing other than my own peace of mind.

That's my story, and I'm sticking to it.

[mattyboy]

well said Richard,
so every 10 years you have a deck lifting party!! ;) count me in when you buy a smaller boat :)


Matty

[olredalert]

-------Off the subject a bit, Rayjay, but what boat is that pictured in your avatar? You said you have a classic but that sort of appears to maybe be a Criterion. Is that possible?.................Bill S

[Donzigo]

Yes, Mattyboy, every ten years = new fuel tank, needed or not.

Post-script: My neighbor (with 1973 Whaler 3o ft or so) from down the canal ,came by when I was cutting the tanks out and said: "Gee it sure smells like gas ever time I go out of the canal, are you dumping gas?". I said: "No". Two weeks later, he says: "I found that gas smell, it was me. I'm getting a new tank too".

Mattyboy, but, bring your saws-all. I don't do deck liftings. On the Z-25, I cut the entire flloor out to reveal the tank. On the Z-33, I cut the tank out piece by piece, (about 12 pieces, actually).

Love to have you, anytime! Bring Coronas!

[rayjay]

It’s not real, or at least not real yet. I have the bones of a Classic 22 project, which will be arriving in CT as soon as I can make the transportation arrangements. As an aside, if anyone knows someone reliable in the boat transport business who is interested in getting a boat from Michigan to Connecticut please contact me off-line.

I have been in love with all Criterions, but especially the Crit II or the SS, ever since I first saw one. Not only the looks, but at least to me they seem to ride and handle better than the Classic 22. Finding this group rekindled that love affair. Since the factory doesn’t seem inclined to re-introduce a Criterion, and there are only so many in other people’s hands, I started playing around with the idea to redo a 22’s deck into a modern interpretation of a Criterion based on a Classic or possibly an “X” instead of an F-22. I am getting quite serious about starting this project after seeing Lenny’s X-18 with the seating moved aft. My avatar is just one of the preliminary pictures and drawings I have been modifying to figure out where to relocate the seating, dash, and windshield.

[Steven Cohn]

Jack,
Where are you located? If you're not too far I can help you (heft) lift-off the deck.
Steven

[zzrhino]

I just went threw what your going threw now. I had a small leak could not find it for the world . I contacted donzigo he gave me some great advice which also saved me a great deal of time and money.He about gave me step by step details and who to contact.I have a 86 z25 were as the bottom had rotted out because of the foam holding water.My nightmare became a easy transition. get a hold of him he has great info.. thanks again richard . PS cuda posted some great shots (may AIR be with you) zzrhino

[Mr X]

The tank manufacturer explained to me that the tank was not strong enough to support and contain the fuel without foaming it in. He said it would "blow out the welds when the boat bounced around over waves".

I know that when my tank was just bolted in prior to foaming it, you could easily push the top of the tank in with your hand. After foaming it in I can literally jump up and down on it and it feels like a rock.

Each to his own, but I went with what the tank manufacturer recommended.

I also installed a new 1" PVC pipe under it and drilled a few drain holes on the top of the bulkheads and sealed the top of the foam with 3M marine caulking.

[Donzigo]

Ted, you make a good point. I'm asking Derek at DRS in the morning that very question. Thanks for the input!