fuel tank leak in overnighter

brodie129

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I have a 86 204 C Overnighter I recently purchased. I now have a fuel leak with noticeable gas at the plug. It is a very slow drip. Any idea where to start looking is replacing a tank expensive? I am a little perplexed at this time.
 

family affair

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Leaks typically start with small pin holes from corrosion. We had the same issue on an older Overnighter. If you get creative you might be able to salvage the tank if the corrosion is isolated. We ended up replacing the tank. I want to say the cost was around $600. Shop around and you might find a better deal.
 

cgmiller

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I am currently dealing with that in my dads Mako..had to cut the deck open to get at the tank. which is glassed and foamed in with very little clearance between the stringers and the tank...a real beotch....I yanked the main tank in my Gulfstream last season and it has some mild corrosion where the rubber strips were touching the tank....I epoxy coated the tank and reinstalled it. I will pull the auxilliary tank this spring...getting the tank out of the grady was easy as grady does not foam them in, instead they wedge them with wood wedges and screw everything in..easy to get out...good luck!
 

brodie129

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thanks guys, I really have not been back to the boat to do a closer inspection. And from what I have read it is time anyhow for a new tank, but I am remaining optimistic to possibly salvage the tank for another year if replacing it could be put off. When I got the boat a month ago I wondered why do these life jackets in the cabin smell gassy? I never had experience with an older boat knowing that the tanks do go bad. Also, the main hatch above the tank, is that supposed to be water tight right? I was cleaning the deck noticed a lot of water coming from bilge so I sealed it with caulk easy to cut and access now. Would I be better to get a rubber gasket then caulk? Same thing back by the transom. Any idea where I could get some metal trim? The trim around the transom is degrading.
She was really dirty when I got her, dry storage every season and well cared for from the first owner. Apparently the guy I bought it from never cared for her as the original owner. Any input would be greatly appreciated.
 

sfc2113

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Same yr boat, fortunatly mine not leaking... yet, if it has the 65gal tank........ I think they all did.....read on. Problem is you will never get it out without cutting off the one or 2 inches from the aft side of the floor and lip. It just dont come straight out and not enough room to tilt it and take it out. Remove those 2 inches and it comes straight out. Seems they corrected this problem a few yrs later, 88 and up. You will have to rebuild the 2 inches of floor and support lip you removed. glass and gelcoat. Been getting quotes in as high as $1,700 and as low as $1,100.00 to do the job. Tank is actually the cheap part. Can almost bet that tank cover is wet and rotting, so rip out that old wood and replace with new wood and glass.
 

cgmiller

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Brodie,

I just pulled the tank out of my father's Mako yesterday. There was no way I was getting it out whole as it was about 3 inches under the aft deck section and the front was partially under the tilter over console. I put a metal cutting blade on a $30 porter & gable 4.5" grinder and cut the tank apart. I cut off the top of the tank and then cut it in half from the inside....aluminum does not spark, so I was not in any danger of blowing myself up..plus the tank had been flushed with water and emptied...If you are not trying to save the tank, which most can not be if already leaking, then make life easy on yourself and cut it apart. You can either have a replacement tank made a little smaller to fit inside the actual opening or buy a premade tank to fit in the hole. The tank in my dad's boat was 75-80 gallons and we ordered a 53 gallon plastic one from great lakes skipper for $243.00 plus $160 shipping. Aluminum tanks were $500 plus and to have a custom one made would be around $700.00. It will take my dad (retired) 2 weeks of normal use to burn 50 gallons of gas, so putting in a little smaller tank was not an issue for him.
 

brodie129

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Thanks for the information. Not exactly sure what I plan on doing. I will look it over. Yes I looked and the clearances and said to myself how am I going to get this out? And I thought the tilt option might be a possibility. I like the idea of cutting it better than spending the money glassing and gelcoat. So I am thinking that having a tank made a few inches shorter would be the ticket. So the side would fit tight and you could shim aft, if needed. The wood looked really solid on this boat on top of the tank, it sucks that I have to do all this. Looking a little closer at the job today and see. Thanks guys. Will let you know what I decide. Any other input would be awesome!!! Thanks again!
 

FlemIslGator

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I replaced mine on my 87 overnighter a few years back. The tank came out whole after removing the access panel above it, without having to cut any fiberglass. It was tight, but I was able to wiggle it out. Once out, it had the OEM tag on it, which was an aluminum mfg company in Perry, FL. I forget the name, but you should be able to find it. If you search this site, you should be able to find more info. I contacted them, and they sent me a drawing to insure it was the same tank. I believe it was around $600 - $700 to purchase and ship. The new tank dropped right in snuggly like the original. I primed the lower half of the tank (I think I ran out doing it) and replaced all hoses while in there. Took some time, but not too bad of a job.
 

gxsess

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Had the same issue in my 86 overnighter. Tanked the tank and replaced it with an expoy coated aluminum one. Not sure were you are but I used patriot marine fuel tanks on the Jersey shore. 650 bucks. I called grady got the mechanical drawing of the tank sent it to these guys and they fanned it in about 2 weeks
 

Riley103

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brodie129 said:
thanks guys, I really have not been back to the boat to do a closer inspection. And from what I have read it is time anyhow for a new tank, but I am remaining optimistic to possibly salvage the tank for another year if replacing it could be put off. When I got the boat a month ago I wondered why do these life jackets in the cabin smell gassy? I never had experience with an older boat knowing that the tanks do go bad. Also, the main hatch above the tank, is that supposed to be water tight right? I was cleaning the deck noticed a lot of water coming from bilge so I sealed it with caulk easy to cut and access now. Would I be better to get a rubber gasket then caulk? Same thing back by the transom. Any idea where I could get some metal trim? The trim around the transom is degrading.
She was really dirty when I got her, dry storage every season and well cared for from the first owner. Apparently the guy I bought it from never cared for her as the original owner. Any input would be greatly appreciated.

Thanks you for the post.
 

cobrapowersys

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Don't even mess around with a patch job. It's time to replace that tank. Anything short of a new tank will not be a wise move.
 

awnuld

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I agree.. once you get the old one out- may as well put a new one in. I had a new one fabricated and put it in my self. The new tank was around $500 and with supplies probably around $650.

There's plenty of posts here on the topic.. and folks that have done it.
 

brodie129

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What size of tank did you replace it with? Where did you get your tank from? Was it the same dimension, I cut the tank in two and got it out since I new the thing leaked like a sive. Debating on dimensions of the new tank. I want it to fit the opening but could make it the same width and a little shorter. Have a fiberglass body man says he can foam it in for me to secure it. The tank had holes in the bottom the size of quarters, it was a job using a drill to connect the dots but I persevered. Any ideas from anyone on what they did to put on top of the tank for support for the lid. It had 2 by 4s on top of it and some boards screwed to it to support lid. I want it secured but found anywhere wood touched the tank there was corrosion and weakening of the metal. Also I found large strips of rubber I believe that was at one time on the bottom of the tank? What I am getting at is how to keep this area sealed from water. Caulk? Rubber stripping? Also I found a drain hole in this compartment, does this drain to the bilge? I tried cleaning this area out but no water would drain and it appeared plugged. Just looking for some input on what to do. You guys have all been very helpful. Its been a project and want this job done right. Any input from owners who have experienced problems in this area would be awesome.
 

cgmiller

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Brodie..I dont know if you are directing your question towards me or not, but I will answer anyway...I replaced the existing tank (80 gallons - 65"x25"x11") with a 53 gallon poly tank (62"x23"x10") that we ordered from Great Lakes Skipper out in Michigan. It was $243. My dad does not travel far in his typical use of the boat, so 50 gallons will last him a few weeks of typical use. so going with a little smaller tank was a smart move and he will not be lugging around a couple hundred extra pounds. We got the tank in a week and we installed it on Saturday. By the end of the day we had the deck reinstalled and sealed back down along with the ttop and console. We sealed the tank in with 4# closed cell foam purchased from US Composites. I used the same stuff in my 21 Mako when I replaced the tank. You mix the 2 parts together and pour it around the tank. It flows into the nooks and crannies and expands to fill everwhere else. Grady did not foam in their tanks like Mako does. Instead they used wedges of wood screwed into the stringers. Strips of rubber were put under the wood and yes, everywhere something touches the aluminum, it causes corrosion. I epoxy coated my new tank with coal tar epoxy and also coated the main tank I yanked out of my Gulfstream. The 2x4's across the top of the coffin support the floor section.

The drain tube at the bottom of the coffin usually has a plug in it to keep any leaked gas from entering bilge.

Keep the coffin lid sealed well with silicone caulk to keep water out of it.
 

sfc2113

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Here is a a link to patriot, he has the tansk in stock, 65 Gal is the right dimensions. I will be getting mine done First week of June, $680.00 installed


http://www.patriotmarinefab.net/Stock_Tanks.html



They will cut the old tanks out and He is going to cutt a few inches off the tank of it can fit without cutting any floor. He is also going to install the vent line foward on the tank, ( a modification Grady made at a later date to the same tank). The current location of the vent line is problematic when fueling on the water.
 

brodie129

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Chris,
Thanks for that important information. You know you never know anything about your boat and the quality that goes into it when you start ripping it apart and looking inside. I will look at GLS and see. My dimensions for proper fitting without modifications to floor were like 22 by 60. And yes I know a guy that does fiberglass work who said he would foam it in for me. Thanks for your input on this situation. It is a huge safety issue not to be dealt with lightly if you want to live long. I appreciate this, thanks again! Keep you posted. One thing I did know was that I could go deeper because of the 2 by 4 on top of tank and then a wedge to support the floor was above this. Crazy, but 25 years later metal gives.