August 11, 2006
Ethanol + Fiberglass Fuel Tanks =
About a month ago, I posted a piece on Ethanol and its damaging effects on fuel systems. In it, I addressed at length the problems associated with aluminum tanks and also touched on ethanol’s relationship with fiberglass tanks. Since that post I’ve received a lot of feedback, mostly about the small bit I wrote on fiberglass tanks. Here’s what I had to say on that subject:
Plastic and fiberglass tanks aren’t really any better off either. For molded plastic tanks, ethanol increases permeation of the tank walls. For fiberglass tanks, ethanol can cause leaks, but more importantly, there are reports that ethanol causes heavy black deposits on intake valves of marine engines which causes bent push rods, pistons, and valves. Testing is currently underway to fully determine the effects of ethanol on fiberglass tanks.
Since that posting I have learned that the alcohol in ethanol gasoline reacts with and dissolves the resin in the walls of the fiberglass fuel tanks. This eventually compromises the structural integrity of the fiberglass tank, causing them to leak. Additionally, the styrene and related chemical byproducts dissolve and work their way into the engine where they can wreak havoc. Unfortunately, it’s believed that all standard fiberglass resins are attached by ethanol.
I have been told that resin manufacturers do have resin formulations that can be used safely with ethanol, however most of the marine industry has little to no experience with these resins. What’s more these resins aren’t widely available. Though these new formulations could prevent problems in the future, it doesn’t address the thousands of boats today with fiberglass tanks.
The good news is that diesel fuel systems are unaffected so far. So, there’s my update for now, I promise that my next posting on Ethanol will involve some positive news!
Posted by ribcraftusa at August 11, 2006 11:15 AM
Comments
How are we supposed to store our boats this winter. Traditionally with MBTE we would fill the tank amd treat with a fuel stabilizer. I recently heard that we should store empty this year as the athanol fuel loses its octane in a shorter period of time even with a stabilizer. Your thoughts on this???
Posted by: brendan at August 16, 2006 10:12 AM
Brenden, I also heard that we should empty our tanks before winter storage. I'd like to hear more advice on how to treat the tanks and prevent corrosion. DO we need to pressure test them every year?
What about old aluminum tanks vs new tanks? Differences?? I have a 1984 tank on an old boat that's bound to be problematic.
Posted by: tibs at August 17, 2006 09:25 AM
These are great questions Brendan and Tibs. The best course of action with the higher Ethanol content these days is to store the boat for the winter with an empty tank. I will do a more detailed posting tomorrow, but once the tank is empty it is recommended that the tank be flushed of all fuel. This will prevent corrosion (aluminum tanks) that could occur from the increased moisture/water content from the Ethanol and will eliminate any chance of damage or deterioration to the fiberglass tanks over the winter. I'll have more on this soon!
Posted by: Fred at August 17, 2006 10:37 AM
