When is it time to replace gas tank?

[Bryan3536]

At the risk of asking a dumb question, what should I be looking for, short of evidence of an actual fuel leak, in deciding whether to replace my fuel tank in a 1990 Overnighter? Is the age alone enough for me to just get it over with? Is any corrosion reason to replace, or should I be looking at something specific? Anyone know likely cost?

We popped our saggy center floor hatch over the weekend (we are having a replacement fabricated). It was moist down there, with an oozy black mildew/mold all over the bottom of the hatch, but there was no real gas or oil smell. The tank was as dirty, but it was impossible to really tell how much wear/corrosion there was - we are shrinkwrapped and stored far from the nearest hose, so we couldn't hose it off and see what we were really dealing with (might bring some buckets down next weekend).

 

[Fishtales]

Hi,
I'd get a good mildew cleaner and hose it out to do the assessment before putting down the hatch. Chances are, once you do this you won't be in there again until you have a problem. It might be good to get a tank inspection while your at it. I assume the tank is aluminum? If it is fiberglass, you probably want to change it due to E10 fuel. When it goes (assuming you don't replace it), you will notice the smell and likely see a fuel trail in the water. Then you will need to take immediate action. Just my 2 pennies.

 

[Curmudgeon]

Usually, corrosion problems occur under the neoprene strips at contact points. That's where I'd start the inspection. Sounds as if you may be a prime candidate ... :wink:

 

[Grog]

You have to pull the tank to check. If it's in good shape, coat with coal tar epoxy and put back in. If the fuel lines are original, replace them while your at it.

 

[sfc2113]

I have the original tank in mine as well,, getting it replaced this spring. but as a precaution I use this, 12v very sensitive to the fumes I poured an ounce of gas onto a rag and putinto into my bilge and it went nuts in a few seconds:

http://www.discount-marine.co.nz/shop/i ... 72d4eed740

 

['84Offshore]

I replaced mine last year........figured it was time.

I removed it for inspection, found some pitting under the rubber straps and decided to replace it.

 

[jeffump18]

Pulled my original tank last week off 1985 Seafarer 227. pitted where the rubber straps are pretty good. Inside looked very clean. Thinking of epoxying it, but will spend a grand to have one made . 93 Gallons. It was my main concern & now will have a worry-free season ahead (yeah, right)!

 

[Bryan3536]

Made several calls to get an estimate for a replacement tank. Anyone got a recommendation for a vendor in the northeast, ideally Long Island?

 

[cgmiller]

I pulled the main tank out of my 1990 23 Gulfstream this summer in order to clean it out. I cleaned it up and found some isolated pitting and corrosion where something was touching it....Grady used coated tanks unlike the noncoated ones I have yanked out of Mako's. I cleaned up the pitting and filled the spots with marinetex and then coal tar epoxycoated the whole thing. The worst place was where the fuel gauge sending unit was installed with stainless steel screws. I had to that area with JB weld and redo the mounting holes.

 

[jeffump18]

I pulled the tank on my 1985 Seafarer 227 last month. It was in good condition, but pitted all over, especially where the rubber strips were. It was a slight pain to remove it, had to cut the 2x4 supports & cut the front lip, will replace it with L bracket mounted to the wall of the front bulkhead. Priced tanks from $700 to $1400. Plus about $150-200 shipping. It was the original 93 gallon tank. Have all winter & spring to pick a builder. It wasn't leaking...yet. It was my one worry. Now I have another-plastic thru hull fittings. That'll be a big project from what I read!

 

[wilson]

I pulled my tanks and just had one big made to fit in the hull, believe it or not I went from a combined 202 gallon (as per grady) to 195 from the fab shop. It was etched and coated, I re did (simular) the tank pads, I made a new support that looks like a railroad track and glassed it in. Next I put down stringers of 5200 and let it cure for a several days, then lowered the tank on top and secured it the way grady did. Best move on that boat so far, next to new hpdi's, those old 200 johnny's sucked fuel so fast it made my wallet ache!

 

[leafybug]

I am in the middle of the same process on my 88 Sailfish. I started with re-building the spongey tank covers, then realized that the fuel tank area was covered in black sludge so I decided to do some cleaning. I ended up removing the tanks finding that they both had a lot of galvanic corrosion. The tanks didn't look too bad until I really got after them with a stiff brush and cleaned the crud off. Now I have found that the inside of the fuel fill hose and fuel feed lines are in really poor condition. My little fiberglass project has turned into a pretty major fuel system upgrade but its better to do it once the right way instead of having to take it apart again in a year or two. I'm having a new tank built for the main, deleting the auxilary tank, all new hoses, and new filters. Best of luck with your project.

 

[cedarholm]

My GW Escape 209 ( 1993 ), has spent it's whole life in fresh water. ( Great Lakes ).

I do see the black slimy stuff, which I clean thru my access plates.

What do you guys think of a 19 year old gas tank used in fresh water?

I get no water in my Racor filter w/clear bowl.

Fuel fill and lines to Racor have never been changed.

Thank you.

 

[ROBERTH]

I pulled the main tank out of my 1990 23 Gulfstream this summer in order to clean it out. I cleaned it up and found some isolated pitting and corrosion where something was touching it....Grady used coated tanks unlike the noncoated ones I have yanked out of Mako's. I cleaned up the pitting and filled the spots with marinetex and then coal tar epoxycoated the whole thing. The worst place was where the fuel gauge sending unit was installed with stainless steel screws. I had to that area with JB weld and redo the mounting holes.

Just like cgmiller said, I pulled both my tanks. Cleaned up with degreaser and sanded down to alumunum to get rid of the original epoxy coating. In pitted areas, coated with Marine Tex. Wiped down with acetone, sanded Marinetex to smooth it somewhat, then wiped with acetone again. Then coated with Coal Tar Epoxy. Came out excellent!
Had to mask off screw holes from underside of fuel tank sending unit hole and stuffed large hole with high density foam rubber. Sanded smooth the mating surface so new sending unit seal would have a good chance at a seal.
Images of Before and After:

 

[ROBERTH]

Also, I used 5200 adhesive caulk with 1/4" PVC strips for the bottom instead of the rubber strips that were not secured and causing some of the corrosion and wear on the bottom of the tanks. These worked out perfectly when put back in and everything fit like needed.

 

[leafybug]

I do see the black slimy stuff, which I clean thru my access plates.

What do you guys think of a 19 year old gas tank used in fresh water?

Its not the age, its the black slimy stuff that can cause galvanic corrosion becasue it holds moisture on the tank. I had a pair of 165 gallon tanks on my last boat that looked brand new and that boat was an 86. Knowing what I recently learned, and am still learning, I would pull the tank, clean it, inspect it, and decide from there what to do. At least then you know exactly whats going on in your boat. I sure was surprised with mine, and I had it surveyed before I bought it and he didnt mention anything about it!

 

[jeffump18]

Did a lot of searching on line for tanks, got quotes from about $1200 down to $550 from amarket.com. They are a clearing house for aftermarket marine parts. They got me a tank for $550 thru RDS tanks, plus minimal shipping ($120) to Mass. from FLA. Took a lot of legwork, but saved 1/2 the amount I was planning on. Just ordered it, should be here in a few weeks. It meets all my requirements. It is a 95 gallon belly tank made to GW specs. RDS & Florida Marine Tank made most of GW tanks for decades. Perserverance pays! :welcome