232 Fuel tank leak check

[postflight]

Recently bought a 2002 232.

It has the original aluminum fuel tanks. I've read numerous comments about expected life of the tanks as 15-20 years. It is, and has been, a saltwater boat. Anyone have any info on pressure checking the tanks for leaks? Good idea or bad idea. Suggestions on how to do it? Looks like one vent hose has been replaced. Any suggestions on replacing all the hoses?

Any tips on how to wash down the fuel tanks? Do I need to remove the floor hatches to do it correctly or just remove the access covers? I've read this is recommended annually, thoughts?

Are plastic fuel tanks available and are they a good idea?

Thanks for sharing your wisdom and knowledge.

Cheers

 

[Sardinia306Bimini]

First have a look here: https://www.greatgrady.com/threads/fuel-tanks.37292/

If you have fuel smell or worst fuel in the bilge then i would pull the tank as pressure testing will only confirm what you already know; a leak.
To inspect a fuel tank completely you would have to pull it completely to be able to inspect the bottom and lower sides
Should you have no problems with fuel smell inside bilge or under the access hatches or water or debris in fuel filter then i would just be happy and go ahead.
If you wanna clean the fuel tank the first time then pull the fuel tank cover to be able to see the tank entirely, check for problems and clean it well where you can reach,
after closing again replace all round hatches as they are prone to leak salt water above the fuel pickup elbows and sender and then every now and then hose the fuel tank with freshwater thru the round access hatches and if on a trailer leave them open for a few days to dry the water. If you check every now end then if the covers are not leaking then hosing the tank could be enough if done once a year.

Yes, plastic tanks are a good idea, they are cheaper and long living but you may loose fuel capacity as you cant't find same size to fit and/or you may have to re route all hoses as the plastic tank connectiosn are in a different place as original tank. This can also include to either cut another hole and install a access hatch over the new location of fuel pickup elbowas and fuel sender to be able to have them accessible in case of a problem, or just close it and leave it closed till you have to access. Depend what is more comfortable in your case.

Chris

 

[seasick]

Open the access plate ( there may be one at each end of the tank) and smell. Do this before gassing up. If no gas smell, that's good. Next time you gas up, repeat the smell test after you gas up. Try not to fill the tank all the way. If after gassing up, you smell gas, but you didn't before you may have porous fuel lines or vent line. You could also have a leak in the tank but that would probably result in gas odors after a decent outing with some banging around. If you have gas odors after filling the tank but didn't when you did the test but not fill all the way, you may have a leaky sender flange. Your nose is your friend

Regarding rinsing the tank. Since the tank is 20 years old, rinsing isn't going to help and may cause harm, especially if you tank coffin is sealed in the bilge. If your tank coffin stays dry under normal use, don't flush it.

DIY pressure testing in my opinion is not recommended and can be dangerous. Tests should be conducted at about 3 psi and even that puts a lot of force on the tank sides.A tank that is approximately 2 foot by 5 foot will be put under 2+ tons of force at 3 psi. As also mentioned, you won't be able to see small pinhole leaks especially on the bottom with the tank in the boat. If you are going to go through the effort to pull the tank to test it, you really should install a new tank.
Replacing an aluminum tank with a poly tank. For smaller tanks, the job is simpler but for larger tanks, you may need to add or reinforce bracing on the bottom and sides. Poly tanks flex more than aluminum.

 

[postflight]

Thank you Sardinia and Seasick for your responses.

 

[Hookup1]

I did my fuel tanks in the Summer of 2023. Search "Islander fuel tank hookup1". I did automotive smoke test on thank previously with no leaks. I pulled my aft tank (easy job) and decided to replace it. Wasn't leaking but didn't look good. For $1,000 it was worth it.

I then decided to pull the forward tank. This wasn't so easy but I did it anyway.

Both tanks and all new fuel hoses. Won't be my problem down the road.

So many variables. Biggest problem is you can't really see what is going on. Depends on the year and model of your boat and how GW insulated your tank to prevent crevice corrosion. Washing the tank down is good to do but the bottom is problematic not so much the top.

Would you put these back in your boat?

 

[seasick]

Outstanding installation!. Can you describe how the underside was mounted (supported, bedded etc) and what materials were used for the mounting brackets, mounting pads (thin sheets of something) and adhesives used. I am curious if there are different recommendations for mounting uncoated tanks as opposed to coated ( epoxy I guess)

One small comment on the install ( I know, I had to say something). The wire harness that is zip tied to the vent hose looks like the wire harness may be tight to the hose clamp screw. If so, vibration might cause chafing and possible damage to the insulation. Just adding a little loop space to clear the clamp will fix that, similar to the loop on the fuel hose harness.

 

[Jimsalv]

Recently bought a 2002 232.

It has the original aluminum fuel tanks. I've read numerous comments about expected life of the tanks as 15-20 years. It is, and has been, a saltwater boat. Anyone have any info on pressure checking the tanks for leaks? Good idea or bad idea. Suggestions on how to do it? Looks like one vent hose has been replaced. Any suggestions on replacing all the hoses?

Any tips on how to wash down the fuel tanks? Do I need to remove the floor hatches to do it correctly or just remove the access covers? I've read this is recommended annually, thoughts?

Are plastic fuel tanks available and are they a good idea?

Thanks for sharing your wisdom and knowledge.

Cheers

Just to maybe make you feel better, many tanks last much longer. I have a 92 Explorer, which I am just now replacing, even though I have no problems with it. Does your tank look fairly clean under the inspection hatches? I would worry more if there is a load of gunk all over the tank. My opinion is if you have no smell of fuel after you fill it, leave it alone until you take care of everything else you want to. You don't need to replace the inspection plates, you should replace the gaskets though. Beckson out of Bridgeport, CT makes them and you can contact them direct for gaskets.

Should you decide to replace, there is no reason for the extra expense of a poly tank, an aluminum tank will last 20 to 30 years. You may also likely have problems with the main hatch, which may likely be need to be rebuilt (worse case scenario).

I assume you had the boat surveyed, if not, also assume that you went through it and inspected all thru hulls, scuppers AND hoses, otherwise all very important on an older boat. Good luck and have fun with your new toy!

 

[Sardinia306Bimini]

Should you decide to replace, there is no reason for the extra expense of a poly tank, an aluminum tank will last 20 to 30 years. You may also likely have problems with the main hatch, which may likely be need to be rebuilt (worse case scenario).

A a correct installed and inside and particularly outside dry aluminum tank will last a very long time,
if the tank is installed wrong, chafing or sitting in water he will last not even 10 years.
I replaced more than 30 fuel tanks when i was working in a shipyard/maintenance facility and most of them wher SS and they rusted from inside out on the stern side where the bend/weld to the stern wall is as water drops collect there and corrode the SS from inside, same on my tractore diesel fuel tank.
My BW 23 Outrage fuel tank leaked after 10 years as he was hiddenly sitting in the bilge water as the 98 hull was too stern heavy with twin 150 hp 4-strokes and bilge water was touching the bare aluminium and developed pinholes.

The key of giving aluminum tanks a long live is correct installation, ventilation and most dry location possible.
Aluminum tank killers are:
Galvanic corrosion due bad/lack of grounding, sitting in or dripping on top seawater, high humidity and temp corroind welds (particularly the fuel pickup elbows and leaking acess hatches dripping saltwater on them.
On freshwater kepth boats its easier to keep them in shape than saltwater kept boats.

Chris

 

[postflight]

Thanks for all your replies and the encouragement. I may try the low pressure (tank placard rates 4 PSI max) check and hope the tanks will go a few more years.

 

[Jimsalv]

A a correct installed and inside and particularly outside dry aluminum tank will last a very long time,
if the tank is installed wrong, chafing or sitting in water he will last not even 10 years.
I replaced more than 30 fuel tanks when i was working in a shipyard/maintenance facility and most of them wher SS and they rusted from inside out on the stern side where the bend/weld to the stern wall is as water drops collect there and corrode the SS from inside, same on my tractore diesel fuel tank.
My BW 23 Outrage fuel tank leaked after 10 years as he was hiddenly sitting in the bilge water as the 98 hull was too stern heavy with twin 150 hp 4-strokes and bilge water was touching the bare aluminium and developed pinholes.

The key of giving aluminum tanks a long live is correct installation, ventilation and most dry location possible.
Aluminum tank killers are:
Galvanic corrosion due bad/lack of grounding, sitting in or dripping on top seawater, high humidity and temp corroind welds (particularly the fuel pickup elbows and leaking acess hatches dripping saltwater on them.
On freshwater kepth boats its easier to keep them in shape than saltwater kept boats.

Chris

Stainless steel tanks? I never heard of that. They must cost a fortune!

 

[Hookup1]

Outstanding installation!. Can you describe how the underside was mounted (supported, bedded etc) and what materials were used for the mounting brackets, mounting pads (thin sheets of something) and adhesives used. I am curious if there are different recommendations for mounting uncoated tanks as opposed to coated ( epoxy I guess)

One small comment on the install ( I know, I had to say something). The wire harness that is zip tied to the vent hose looks like the wire harness may be tight to the hose clamp screw. If so, vibration might cause chafing and possible damage to the insulation. Just adding a little loop space to clear the clamp will fix that, similar to the loop on the fuel hose harness.

New tanks were padded out with 1/4" x 2" white neoprene strips attached to the tank with 3M 4000. The area where the blocks screw down to secure the tanks were padded out with 1/8" x4" x 6" white neoprene strips attached to the tank with 3M 4000. No special prep under tanks. Tanks are secured with original factory white HDPE blocks secured with new Torx head stainless wood screws.




Original factory tanks were padded with a neoprene strip with self-adhesive backing. Over 25 years the adhesive broke down and the strips and adhesive backing broke down and separated. They even moved around a little. This trapped moisture against the tank and promoted crevice corrosion.

 

[seasick]

Thanks for the details. Again, very nice work.

 

[Sardinia306Bimini]

Stainless steel tanks? I never heard of that. They must cost a fortune!

No, they are about same as a aluminum tank in US, or slightly less.
Thats what 90% of Italian boats pre 2010 have, nowadays most have poly tanks if they fit the available space.
The big adavantage of Aluminum or SS tanks is that they can be built to shape to maximize fuel capacity.
Below is the 120 gallon one we pulled August 2023 out of my RIB
Chris

 

[postflight]

Thanks for all the comments, suggestions and encouragement. Replaced the main tank with an upgraded aluminum one. Thanks to all your tips, it went really smoothly. The job sounded a lot harder than it was to get done.