Aluminum fuel tanks

[Bass Cat Boats]

Good question… They will move to plastic tanks as tooling is completed for those tanks. Any ethanol issues in aluminum tanks is not necessarily going to happen and generally will be downtstream several decades with fuel tanks. Those issues are able to be managed today, even non existent with care. This is through daily maintenance and additive costs and are not component ending tragedy if done. Galvanic corrosion requires water in fuel to have corrosion challenges. Thus maintenance at this level is important that it continues when fuel is static in tanks and not being used. You do have to keep water out of aluminum tanks when grounding is present. ts not something we normally do your right as we usually go highest long term possible level of component use. On ethanol, its just like having A1 fuel lines in the 1980s when no one else did. Then thats something which most builders still dont use A1 today. In this case they had no options with present marine demands as the tooling for fuel tank molds has been under for months. The present marine demands has the molders fab shops over worked and extended completion times.

[Bass Cat Boats]

NMMA Statement: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.

[Bass Cat Boats]

BCB, Thanks for the quick comeback. I think I understand, its a timing issue. I ordered a Caracal hopefully its still Plastic.

[Bass Cat Boats]

It is still plastic (Caracal) and we completed the previous topic reply so others understand fuel additives when stored are how you eliminate the issue. No standing water, less corrosion in the tanks. Many aluminum fuel tanks actually get degradation outside and caustic pitting from water and electrolysis also. Weve never seen an old late 1970s to mid 1980s BCB aluminum tank fail, though we have seen them ugly in areas.

[bassinman2002]

Thanks BCB, Both for answering and giving me peace of mind with the Caracal.

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