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Bertram31.com General Bulletin Board
Coast Guard Response to Ethanol Questions
Posted By: Chiles
Date: Tuesday, 4 April 2006, at 11:35 a.m.
The CG responded to my questions. I have both sections of their response, including the Q@A that I did. Here is part 1.
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The linked articles that Mr. Cridlin has provided are interesting. After speaking with you on the phone it sounds like you have heard more about this issue than I. But, here is my input to a response that surely you are better prepared to provide. As you may note I am copying Mr. Cridlin on this e-mail. Please ensure that we address all of his questions. My input is not complete and I defer to you to supplement/amend for the CG response to his questions. As you know, I am involved principally in commercial vessel standards. As discussed, the applicable regulations for subject parties' vessel are 33 CFR Part 183 ( for Mr. Cridlin's reference the CFRs can be viewed on line at http://www.access.gpo.gov/nara/cfr/cfr-table-search.html#page1 . As far as I can tell the only real limitation for existing recreation boat fuel tank construction is in 46 CFR 183.512:TITLE 33--NAVIGATION AND NAVIGABLE WATERS
CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
PART 183_BOATS AND ASSOCIATED EQUIPMENT--Table of Contents
Subpart J_Fuel Systems
Sec. 183.512 Fuel tanks: Prohibited materials.
(a) A fuel tank must not be constructed from terneplate.
(b) Unless it has an inorganic sacrificial galvanic coating on the
inside and outside of the tank, a fuel tank must not be constructed from
black iron or carbon steel.(c) A fuel tank encased in cellular plastic or in fiber reinforced
plastic must not be constructed from a ferrous alloy.[CGD 74-209, 42 FR 5950, Jan. 31, 1977; 42 FR 24739, May 16, 1977]
Basically, it looks like if they want to replace their tank with stainless steel than they can do that.
If the vessels were certificated and inspected vessels under subchapter T (carrying greater than 6 passengers for hire- 46 CFR 175-185), they would not be allowed to build gasoline fuel tanks with stainless steel. Problems with crevice corrosion have restricted their use in "T" boats. In subchapter "T" fiberglass may be used as fuel tanks for diesel if specified conditions are met. But, fiberglass can't be used for gasoline tanks. Table 182.440(a)(1) in subchapter "T" allows for, under specified conditions, the use of Nickel-copper, Copper-Nickel, Copper, Copper-silicon, steel or iron (generally galvanized for gasoline), and aluminum in fuel tank construction.
ABYC Standard H-24 Gasoline Fuel Systems H-24.18.2.2 also restricts stainless steel tanks to cylindrical, with domed heads, and a capacity of less than 20 gallons (75 liters).
But, as you stated in our phone conversation, a recreational boat owner need not comply with this standard when replacing their fuel tank.
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Part Two Q@AMr. Cridlin:
I will attempt to answer your questions.
"Does the USCG have any information for aluminum etching by ethanol enriched fuel?"
We have had one or two questions on the subject, but have no evidence or data.
"What can be done to prevent crevice corrosion on stainless tanks?"
Fabricate the tanks without crevices (a difficult task) or construct them of a prohibitively expensive grade of stainless steel.
"Does the USCG recognize this as being a safety concern?"
Yes, insofar as we think the ABYC standard (H-24, see LCDR McClellan's remarks below) is a good idea, however we do not have accident statistics to support rulemaking prohibiting stainless steel tanks.
"If this were your boat, what would you do?"
Probably have an aluminum tank fabricated and installed, however please do not construe that as a Coast Guard endorsement or recommendation.
Regarding ethanol in gasoline, we feel at this time the industry is aware of the problem and is addressing it. Our statutory authority for safety defect recall is limited to ten years, so the old fiberglass tanks are not something we can deal with, other than a possible safety alert pending more concrete details.
I recommend NMMA's website as a good resource on the issue.
http://www.nmma.org/government/environmental/?catid=573
******************************************I'm not sure this clarifies much more then we have already discussed, but it's nice to know that the CG is becoming more and more aware.
Chiles
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