Engine - Fuel Tanks


October 23, 2012

Good day,

After 30 years the aluminum fuel tank of "Corret" developed pin holes. This tank was manufactured by Santa Ana tank co. All experts recommended getting a new one.

Even though I live 8 miles from Annapolis, Md. the yachting capital of the USA according to them, I could not find a similar tank for less than $1000.00 before installation. Thanks to the web, I found a welder in Bristol. RI for half the price. Welder's quote for new tank.

After giving them a list of the measurements by email, I received the new tank within 10 days of the order. It fits perfectly in the space and after reconnecting all hoses and grounds and adding fuel, the engine (Pathfinder) started immediately.

Enjoy the pictures below. Should you have any questions, let me know.

Philippe Masiee

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old tank
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Fuel Tank Drawing
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strut bolts
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behind tank space
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new tank
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old & new tanks

Response from Clive Openshaw:

I had a fuel tank made of 316L stainless steel by Tarheel Aluminum of Charleston, OR, phone # (541) 888- 6708.

They copied the old mild steel tank, I am very pleased with the result, the cost was $675 and the tank will outlast the boat. If you decide to go with SS, use 316L, the L means an alloy sutible for welding.

Clive Openshaw

July 20, 2003

Well I did get my new Pathfinder in the Freeport. Before I started the engine I wanted to make sure the fuel system was clean so I checked into "polishing" and "cleaning".

The prospects were time consuming and pricey. To get to both sides of the baffle I would need an inspection plate on both sides and a couple of unattractive access plates on the floor of the cockpit above them. I then would still have had a 22 year old tank.

A brand new shinny 32 gallon aluminum tank was a FRACTION of that price along with a handy dandy cartrige-type fuel filter/water seperator set up. There was incentive to get it done once the UPS guy put it on my front porch.

The new tank is a common RDS aluminum tank that sells at West Marine for $220. It came with a built in gauge and an electric sender was a separate accessory if desired. The width was the same as the old tank which made it pretty easy to box in. The length and height were shorter and did not cause any problems.

By comparison, tank cleaning ranged from $250-$350 for the job. Inspection plates and their installation are necessary for access and require additional costs as you can imagine. The center tank baffle runs fore and aft and completely separated both sides. This is a doable option to replacement of the tank.

With the help of Mister Sawzall, the 55 gallon tank came out of the starboard lazarette and the new one took its place. The starboard lazarette on the Freeport was the best access and required cutting away the face. I was able to cut above the lower corner and maintain the structural integrity. This part of the job is not for the weak minded and does require reglassing knowledge. The hassle was in getting the old fuel out and getting rid of it.

I am not sure what history was behind this Freeport, but it sure had some crud in the tank and made Art's tank look like surgical equipment. There was both slimey and gritty spooge on both sides of the baffle from 1/4" to 1/2" deep, which was loose enough to slip over to the pick-up tube on some windy day in a land far far away. There was some pitting on the bottom and I am not sure how much longer it had before leakage began.

Attached are a few pics (no fiber optics needed here). I think I should now:
- keep my tank reasonably full to avoid condensation
- use an additive as recommended
- sail frequently to keep it stirred up

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fuel tank 1 fuel tank 2 fuel tank4
Smokey Stover

Saturday, March 8, 2003

I don't know how many of you have had a close look inside your fuel tank, but I dare say that once you have, you'll wish you hadn't. Attached is a photo of the forward section of the inside of the fuel tank on my '78 Islander 36. Access is provided through a six inch port cut in the starboard forward side of the tank.

The photo was taken after I had spent considerable time cleaning the tank as well as I could considering the limitations involved. The photo shows that there remain considerable black deposits from residual algae buildup, particularly in the corners and in the weld seam irregularities along the edges.

What it doesn't show, and what I can't get to in order to clean, is the rear half of the tank that is inaccessible because of the baffle. If that section is anything like the front was, and I see no reason for it to be otherwise, it probably has deposits near the corners with about an eighth inch of (algae skeletal)? gravely like material.

I would guess that this tank is probably typical of what we would find in many boats of this age. In fact this tank may be cleaner than many since I have had the fuel polished 3 times over the past six or seven years and did hastily clean the dry tank through this access port about two years ago. My principal concern I will get to in a moment, but an additional concern I have is the rate at which the contamination seems to reoccur. I treat the fuel with a biocide per recommendations, yet my Racor filter had such "mud" caked in the bowl after only eight or nine months, that I had to dismount the entire filter in order to clean it since the drain was fouled and wouldn't respond to inserting tools to free the debris.

I probably could just refill the tank and probably get several more years of use with a conscientious program of fuel treatment, filter replacement, and perhaps fuel polishing (though that process has disappointed me in the past with the amount of debris left behind in the form of deposits on the tank surfaces)

All that being said, there is one other problem of great concern and I'm not sure if you can see it in the photo. The aluminum tank bottom shows a certain amount of corrosion in the form of pitting and scaling. To what degree it can be tolerated is my question. I would imagine that it could probably go several more years. Yet on the other hand, the thought of the tank suddenly corroding through such that twenty-five or more gallons of diesel fuel end up in the bilge only to be pumped over the side by the automatic pump is a nightmare. The magnitude of the fine that would create makes the process of tank replacement seem cheap by comparison.

So the question is: to maintain the old tank with some inconvenience and at some risk or incur the greater expense of replacing the tank. At this point I would be interested in anyone's thoughts or recommendations on the subject. I am particularly interested in hearing of any possible non metallic material that has been used successfully for diesel tanks, if any have or whether it is better to stick with the tried and true metallic materials. Also, I would be interested in any recommended manufacturers and installers.

Can a tank of the same original dimensions be retrofitted since it appears the original tank was installed prior to the deck being added? Would there be any advantage to installing two tanks in the space of the former one, leaving one empty but available for long cruising situations. I use so little fuel in the course of a season that a tank half the size of the original would be plenty and think of the weight that would save, considering that a tank with any fuel in it should be kept near full .

Looking forward to your ideas.
Art Fowler BETZENART@aol.com
"Zenith" (Sail No. 472)

Click to enlarge.


From: noelo@ix.netcom.com
Friday, November 23, 2001 10:00

Subject: fuel tank replacement

Fellow I36's,

I discovered a pin-hole leak in my diesel fuel tank recently! Of course I'll need to pull the tank and have it replaced. I was wondering who has done this and how they did it (before I get started). I'll probably pull the hot water tank over the engine too. It looks like it has seen better days and also would give more room to work on the fuel tank. I have a Westerbeke L-25 engine in my 1979 I36 boat. I am hoping that I can pull the fuel tank out through the starboard cockpit cabinet without pulling the engine out.

I would also be interested in knowing what type of replacement tanks people are using (aluminum or synthetic materials) and which shops or manufactures do this work. Thanks for any help or thoughts.

Noel O'Brien
"Free Time"


Ah yes, the dreaded fuel tank leak. Lived through that on my '73 I36, and got the tank out by cutting away part of the plywood bulkhead in the port quarter berth where there is an access door to the water heater and stuffing box. I did take out the water heater too. I don't think the tank will make the turns to come out through the starboard cockpit locker.

While you have the tank out, check the bolts that hold the prop shaft strut. They are under the tank, and almost impossible to reach with the tank in place.

As for material, I think I've read some emails that various materials have been used. In my case, it is a steel tank, and repaired with new plate.

Good Luck,
Rick Van Mell

From: <noelo@ix.netcom.com>
To: "Sandy & Rick Van Mell" <vanmells@ix.netcom.com>
Sent: Monday, November 26, 2001 11:20 PM
Subject: Re: Re: fuel tank replacement


Thanks for your reply. What you described in removing your tank appears to fit my situation too. Did you replace your water heater; and, if so, where did you get that tank from?




I didn't replace my water tank, and it's held on for all these years (did the fuel tank work in 1981). I think I have seen water heater replacements in the West Marine catalog which look about the same as ours if you are inclined to replace yours.

The water heater doesn't look real pretty, but it keeps on giving great hot water. We typically run about an hour under power when we go out and that gets the water hot, and when we cruise on an overnight, about once a month, we use the 110 volt heater and leave it on for 24 - 48 hours with no trouble.

I have had to replace hoses over the years, and while you have the tank out and it's easier to get into that area, suggest you replace all of the water hoses from the galley sink to the hot water heater and at least back to the access locker under the port quarter berth. The hoses to the engine are significantly heavier on our boat than the hoses to the sink and "Y" connectors at the bottom of the cockpit locker.

Good Luck,

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