Gas Tank Leak

G

gamecoc430

Member
Joined
Aug 25, 2009
RO Number
31687
Messages
40
1999 Carver 350 Mariner. Have just developed a leak in the starboard gas tank. Looks like I need to remove the genset and starboard engine to remove gas tank to repair/replace. Any other suggestions or options? Is there some type of gas tank repair liquid to pour into an empty gas tank to seal up pinholes/small leaks without totally removing the tank? Anyone use one of these that worked? Would it be better to cut out the starboard seating in the cabin and try to remove the tank by going through the cabin rather than removing the genet and engine? Thanks for any suggestions.

Bob
 
Would you really want to risk your life (and your family's) on a band-aid approach to a leaky gas tank? I had to replace the tanks on my very much older '86 Mariner. The port engine had to be removed to replace the tank. The starboard tank was able to be replaced by removing the starboard bank exhaust manifold and rear deck-dunno how much you newer Mariner set-up differs from mine. You might want to contact Carver-Ron Brown is a name that always seems to be mentioned at Carver for any technical questions about older boats. Good luck and be prepared to break out your equity line of credit card.
 
Thanks, cmariner32, definitely do not want to risk anything. I was really hopping to find a better way to remove the tank than removing the genet and engine. B O A T - except in this case it's probably going to be B O A T T the additional T might stand for two or three!

Bob
 
Gas tanks have baffles inside that would prevent the use of a bladder inserted into them. Having a certified weld shop build a replacement aluminum tank should only run $1,000 or so for a 100 gal plus or minus tank. If its a newer boat, check with the manufacturer to see if there was a recall-Carver did have a recall on some vintage tanks-check with Boat US to see if yours may be at least partially covered.
 
Thanks, guys, this is kind of what I was looking for, something that might seal a pinhole without removing my genset and engine to get the tank out A bladder might work if I can find the right type/size. I'll also call Carver tomorrow for their advice or hopefully recall info. Thanks again, this is my favorite forum!
 
I had my sender off the tank a few season's back and was able to look into the tank. I didn't recall seeing any baffles. Mine is a 2001 model and the tank is 90 gallons, hanging style.
 
I'm replacing two of them on a Silverton right now. Only one is leaking, but with my luck the other one can't be far behind. Replacing with plastic. In our case, rear salon walls were cut out as opposed to removing engines. It is a long drawn out mess, and requires breaking out 4 to 5 B.O.A.T.S!! Good luck, but if you have a twin consider replacing both.
 
Thanks again, folks. PeteMrrs, this is what I was considering rather than removing engine and genset. Will take careful cutting to make sure it doesn't show when everything is put back in. And careful measuring to make sure the old tank and new one can fit through the sliding door. pdecat, thanks for the tank maker (I hope). Will check it out next visit to the boat.

Bob
 
Pete. Idont understand. Is the hull being cut?
 
No we cut the inside walls in the rear salon, then sliding the tanks back and at an angle for removal, The "fiberglass guy", will then use a combination of fiberglass and inspection plates to rebuild the areas affected. After the repairs are completed, the rear seat cushions will be rehung, and all plates will then be covered.

The drawback to doing it this way is that the holes that are big enough to remove the old tanks, (with the help of a sawz-all), are not big enough to accommodate new OEM tanks. We were faced with cutting larger holes, meaning more dollars spent on refinishing, or going with smaller replacement tanks, meaning less fuel capacity. In the end we choose smaller tanks, and lost about a total of 30 gallon capacity. I second guess myself on this decision on a daily basis.

Leave room for unexpected expenses. The new tanks have a different size fill plate than the old ones, so the plumbing needs to be reconfigured. Also while looking at possible removal plans we discovered that the bottom shell of the water heater was pretty well rusted, so we need a new water heater.

What's most frustrating, is aluminum tanks have an expected lifespan of 12 - 15 years, far shorter than the lifespan of the boat, or boat loan :( and the original builders don't give a moment's thought to replacing tanks. To make matters worse our boat is a Silverton, and they are no longer around to offer any technical support what-so-ever.

Bottom line: If we get the entire job done for under $4500, I'm very happy, but I am really expecting $5000+.
 
Bob,
You should call Carver to see what they suggest, have a friend that owns a Carver (late model) and he raves about how helpful their support is. Also, I would try to figure out what caused the leak. I remember reading a while back on a Silverton Club site about a problem where the tanks rusted out because Silverton had the tanks laying directly on the shelf where the tanks were mounted. The rust started from the outside and worked its way through that way. It was suggested by Silverton at that time that when re-installing the new tanks that they sit on a cross brace evenly spaced to allow air to pass under the tank.

Lastly,
I agree with Pete about replacing both of them, as Pete noted, the other tank will not be far behind. I would think that it would be less costly to do both at one time as opposed to doing them individually.

Something else you should look into is cutting out the side of the hull of the boat and removing the tanks that way. I have seen this done on larger boats. I know it sounds barbaric, but it is not.

Again,
Call Carver, I am sure your not the first person to replace tanks on this model :)

Best of Luck
Walter
 
I'm trying to picture it to explain it and am having trouble but here goes anyhow.... Could you use multiple small tanks instead of one larger (albeit smaller gallonage) tank joined to a manifold system?
 
Walter is right about the flaw design in the Silverton's. This as well an the angle at which the Silverton Express Cruisers sit in the water all added to the problem.

David, I assume that what you are describing is certainly possible. The issue was more the shape of Silverton's tanks. The were not rectangular but more v shaped on the bottom in order to fit the contour of the hull. We installed bracing across the inner wall of the hull in order for a flat bottom tank to sit properly, as well as keep the new tanks up and out of any water that may accumulate in the bilges. In my case we are past that option at this point.

Gamecock, I just realized that you are in SC. I can give you the name of a good guy who will go over all options with you, if you want.
 
Thanks, everyone! My mechanic has decided the best option is to remove the tank through the cabin. The original tank actually sits below engine stringer level which means we may have to cut away a portion of the stringer to remove the tank, after removing the genet and engine. He MAY be able to tip the tank slightly to get it over the stringer but clearance above the talk is barely inches, not enough to lift the tank straight up and over the stringer. I don't want to cut into a stringer! As stated above, he will sawsall behind the seat cushions to open up enough area to remove the tank through it, then reattach and glass over the cuts after installation of the new tank. Even if the glass job is not perfect it will be covered by the seat cushions. We're in Columbia located on Lake Murray. I feel confident in my marine mechanic but would be glad to talk to anyone in this area to pick their brains!

Again, thanks everyone for all your help and suggestions. I would be lost without all the support and information shared on BoaterEd.

Bob
 
Some of it is, however, it would still require cutting fiberglass to replace the gas tanks. The settee framework, back, and base is fiberglassed into place on top of the salon floor and the settee is what is in the way of getting the tank(s) into the cabin area...... thanks, Carver! As suggested above, it would be possible to cut through the starboard side of the boat and possibly replace the tank using that method. I have seen pictures of that method used to replace large diesel engines on yachts. But the quality of fiberglass work would increase dramatically going through the hull side.

Good idea, though! Thanks.
 
KiDa, we might well have to use either a smaller tank, or manifold with a couple of smaller tanks. I'm not worried about losing several gallons of capacity. I'm located on an inland lake approximately 60 miles by 14 miles in size and we usually run at hull speed. Total gas capacity today is 250 gallons. If full, that would last me for years! In fact, this is the first time in years I have filled the tanks to just half full. We usually keep them around a quarter full (total of 60-75 gals). Don't need the problems with stale gas!

Thanks,
Bob
 
You must log in or register to reply here.
Back
Top