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F32 rear fuel tank replacements

Posted: Tue Nov 22, 2011 9:50 am
by zbigk
Hi All,

The rear fuel tanks in "Time Out" are disintgrating. I started picking up a fine white sand like substance in the water/fuel separators. So I am in process of shopping for replacement 60 gallon tanks. I am looking for drawings to provide so i can get estimates. I do have drawings for 99 gallon tank replacements but I decided not to go that route.

I sent requests for prices to the following:

http://www.sptanks.com/webdev/home.htm
http://www.amarket.com/alum.htm
http://www.custommarinefueltanks.com/
http://www.rdsaluminum.com/marine-custom.html
http://www.patriotmarinefab.net/
http://www.speedytanks.com/tank/index.html

Any advise would be appreciated.

Thanks,

Posted: Tue Nov 22, 2011 10:08 am
by g36
on my 78 f32 i had the same white sand and other internal tank corrosion once i started looking.
i replaced mine this past spring with new tanks from sptanks. i had the tanks built to the same deminisions i already had. upsized the aluminum to larger so it would bunk properly in the same tank mounts. with out any other support. had all the fittings put in the same spots. tanks went in very easily. i painted the bilge while they were out when i got done and new tanks installed i hated to cover it back over with the deck. gotta love that cockpit floor just lifting out for the exchange. i am very happy with the money i spent with sp tanks

you dont need any fancy drawings. spend a few minutes with a ruler and draw them out measure the distances for the fittings and submit it. i know if sp has any questions they will contact you. they wont start till everything they need is given. you may even ask if they still have mine from this spring

Posted: Tue Nov 22, 2011 11:05 am
by Stripermann2
This is what I have on my boat and I believe they are original as supplied to Trojan, at some point in time.

http://www.floridamarinetanks.com/

Posted: Tue Nov 22, 2011 12:32 pm
by Struts and Rudders
tank builders that serve the custom and production boat markets in and around the Carolina region seem to price or quote by the gallon.
I have found quotes ranging from$ 8.00 to $9.50 per gallon for your comparitive information.

SRD
F36

Posted: Tue Nov 22, 2011 2:21 pm
by Commissionpoint
+1 on SD Tanks. They make a great product. Will custom build anything you want as well. Pricing is also quite competitive.

Posted: Thu Dec 01, 2011 8:55 am
by mtwolf
Just make sure they are Coast Guard approved. If something went wrong, (heaven forbid a fire,) the insurance company would have a field day.

John
1973 F-31

Posted: Thu Dec 01, 2011 9:46 am
by rossjo
Ethanol is very corrosive.

Here is a position paper by the National Marine Manufacturers Association (NMMA) on Ethanol ...

"The Negative Affects of Ethanol on Recreational Boat Fuel Systems

The National Marine Manufacturers Association (NMMA) opposes the use of marine fuels that contain greater than 10% ethanol content by volume. This position is based on safety and durability concerns and supported by many well documented studies.

According to state boating registrations, there are over 12 million recreational boats in the United States. Boat builders utilize five types of materials to fabricate fuel tanks. These are aluminum, steel, cross-link polyethylene, high density polyethylene and fiberglass. For a rough estimate of today’s numbers, there are approximately four million boats that have aluminum fuel tanks; approximately seven million have steel or polyethylene tanks, and less than one million have fiberglass tanks. The data clearly indicates that the increased use of ethanol in gasoline has raised safety and durability issues for aluminum and fiberglass fuel tanks.

Aluminum Fuel Tanks

In the case of aluminum tanks, aluminum is a highly conductive metal that relies on an oxide layer for its corrosion protection properties. Low levels of ethanol, such as E10 (10%), are usually not a problem in aluminum tanks because the oxide layer provides a good measure of protection. The problem occurs when the ethanol content is increased.

There are two mechanisms that occur with ethanol. Both mechanisms are a result of the hydroscopic property of ethanol, meaning it absorbs water. The more ethanol in the fuel, the more water there will be in the fuel tank. Water not only causes the tank to corrode, it also causes the corrosion particles to clog fuel filters, fuel systems, and damage engine components. The corrosion rate can be accelerated under a number of conditions if other contaminating metals are present such as copper which may be picked up from brass fittings or as a low level contaminant in the aluminum alloy. Chloride, which is a chemical found in salt water, will also accelerate corrosion. In the long term, corrosion can perforate the aluminum to produce leaks that would cause fuel to spill into the bilge and end up in the environment. In the worse case it could cause a fire and/or explosion hazard. Boat fuel tanks are often located under the deck next to the engine where the operator might not be aware of a leak until it was too late. .

The second mechanism that can occurs with the increased use of ethanol based fuel in aluminum tanks is galvanic corrosion. Gasoline fuel is not conductive, but the presence of ethanol or ethanol and water will conduct electricity. The galvanic process that occurs to aluminum trim tabs, stern drives, shaft couplings, etc. will occur within the aluminum fuel tank. Boat builders are able to protect exterior aluminum boat equipment with sacrificial anodes known as zincs. Sacrificial anodes are not a feasible option for the interior of a fuel tank.

Fiberglass Fuel Tanks

NMMA is in the early stage of evaluating the effects that ethanol in gasoline has on fiberglass tanks. Boat U.S., the boater advocacy association, recently issue a consumer alert reporting that owners of older yachts have experienced leaking fiberglass fuel tanks. There have also been reports of heavy black deposits on the intake valves of marine engines resulting in bent push rods, pistons and valves. Some of the preliminary analysis conducted by an independent lab found the deposits to be di-iso octyl phalate, a chemical found in the resin, gel coat and filler used to make fiberglass fuel tanks.

An initial theory is that when ethanol is introduced to the fuel tank the very small ethanol molecules diffuse into pores between the resin where they dissolve the unreacted phalates. Since the phalates are in solution they are able to pass through the fuel line filters. These phalates have exceptionally high temperature stability and remain intact when the fuel evaporates in the carburetor or undergo only partial decomposition in the combustion chamber thus creating the heavy black deposits on the engine’s intake valves.

Unlike aluminum, NMMA has yet to identify the effect that ethanol in fuel has on the tanks integrity or even the root cause of dissolved phalates. The theory is that it is being caused by ethanol and we know that ethanol dissolves phalates, but more testing is currently being conducted.

Conclusion

As stated in the opening paragraph, the NMMA has serious safety and durability concerns with the incremental increase in ethanol content in gasoline motor fuel. The majority of marine engines in use today are open loop systems that are designed, engineered and calibrated at the factory to operate with fuel containing either 10% MTBE or ethanol. Changing the fuel that these engines were designed, engineered and calibrated for will negatively effect drivability, exhaust and evaporative emissions, and potentially damage the components.

While these issues are significant, the boaters have a far more serious issue. The available data indicates that aluminum and fiberglass fuel tanks and butyl rubber fuel hoses that are currently being used will fail if the ethanol content is increased to 20%. That is not an emissions issue; it is not a drivability or durability issue. It is an issue that needs to be taken far more seriously. It is a threat to the health and safety of the boaters in your state.
"

ref: http://www.google.com/url?sa=t&rct=j&q= ... VjRUaFK7Bw

Posted: Thu Dec 01, 2011 10:03 am
by larryeddington
just got my new SP Tanks for my F28 increased size from 50 gal to 75 gal and though not installed as yet sure look good.

Posted: Thu Dec 01, 2011 10:45 am
by Stripermann2
Larry, or anyone else...does SP, have spec sheets or previous tank replacement drawings for specific boat models or do they start from existing tank measurements provided to them?
I would think a company like SP, in as long they have been doing this, would readily know the tank dimensions and a quote for say a Trojan F-32 or a Searay 34 sedan for example?

Posted: Thu Dec 01, 2011 10:57 am
by larryeddington
On the SP website they have an application that gives several designs of tanks which will tell you how many gallons the proposed tank will hold.

I measured my space and sketched it up (they have a page to show you what they need) called them and they gave me a proposal on what I wanted.

Otherwise there is not standard it is what you need and what accessories you want on the tank such as tabs, clean out port etc.

My tanks appear to be exactly as I sketched and though they are still in shrink ramp, SP says they are tested per USCG regs and a placard is affixed to that affect.

Larry

Posted: Thu Dec 01, 2011 7:14 pm
by mtwolf
I replaced mine a few years ago. Florida Marine tanks made the replacements but put ther wrong sending units in the tanks. I ended up replacing the guages and tank senders. From what I gather they no longer make the round tanks for thr F-31. The fuel line pick up, on the back tank, was scaled shut.

Tanks

Posted: Sat Dec 10, 2011 1:45 pm
by Fishblues
Ill open up a can of worms... Just put two new Moeller tanks in my F32 and I love them. 58 gallons each.

Image

Posted: Sat Dec 10, 2011 11:50 pm
by gettaway
the plastic tanks look great, I am thinking of the same for mine when the time comes, is the opening in the center of the tank the baffle?

Posted: Sun Dec 11, 2011 12:31 am
by k9th
I replaced both my tanks last year with tanks made by SP. They are well made, high quality, and fit perfectly. I would highly recommend them.

Re: F32 rear fuel tank replacements

Posted: Thu Sep 20, 2018 2:33 pm
by TADTOOMUCH
how hard was it to get the old cylinder tanks out. mine are hard piped in and I am not sure where to or how to disconnect the pipes. Where did you start?