Deisel and ethanol

[David Arnold]

I last filled up my fuel tank in the late fall (about 1/8 shy of topping off to allow for expantion and limit condensation) for winter storage.   Now that the fuel is mixed with a small percentage of ethanol can I fill the tank when it is down to about 1/2 or am I better of running the tank almost dry before I refill?

[Ted Pounds]

Your diesel shouldn't have any ethanol in it.  That stuff is just for gasoline.  And even in marine gas engines ethanol can be a bad thing  .  Also, in general, the fuller you keep your tank the less condensation you'll pick up in it.

[steve stoneback]

David,
By chance did you mean Bio-diesel?
sps

[David Arnold]

I thought ethanol was an additive for both gas and deisel fuels.  Looks like I was mistaken. 

[Ron Hill]

David : I surely hope that the government doesn't add anything to the diesel that has a lower flash point (like alcohol has) - or we'll all be changing the timing on our diesel engines!!!  I've even made a number of posts recommending that people NOT purchase any diesel water absorber (like the Starbrite brand) as it contains alcohol.  (MDR brand is alcohol free)

They are adding alcohol to gasoline and it can harm some plastics/fiberglass by dissolving it.  Alcohol is no problem to the gasoline engine, but many years ago you might remember that that mixture attached the older auto fuel lines and seals.

BTW, of late I've noticed that the diesel pumps are placarded with the "Low Sulfur" road fuel or Hi Sulfur off road fuel.   

[Footloose]

The subject of bio-diesel came up at the boat club this afternoon.  One of the opinions was that bio-diesel will break up the sludge in your tank and start sending it through your filters and injectors and that if you decide to use it you had better be prepared to change your filters at a moments notice.  He stated that the deposits will rapidly plug filters.  It will also clean your diesel tank, but at a high and potentially dangerous cost, ie shutting down your engine without notice.  Has anyone else heard this or do I throw it on the rumor pile.

To add fuel to the fire, I have talked with a diesel mechanic (trucks not boats) who told me that when the company he worked for began using bio-diesel they had to use larger filter as the finer filters were getting clogged up.

[Terry Forshier]

Last year I started running biodiesel in my 2QM15 Yanmar diesel in my old O'Day 30. I used about 20% to 25%% blend. It ran very well, did not smoke or soot up the transom when a load was on the motor and I did not alter changing the filters schedule. I did have a newer fuel tank so that did not cause a sludge breakup. The smell was like popcorn not the oiley smell from diesel. I also burned a bit more fuel with the mixture. Before I was using a gallon for each 2.5 hrs and with the addition of the biodiesel it was using more like a gallon per 2hours. I have not tried the blend with the Cataling  and the Universal only because I had to drive an hour away and purchase the biodiesel in 5 gallon cans I had to supply. Terry

[Ron Hill]

David : I've never heard any of the characteristics that you mentioned of Bio Diesel.  Have no idea why it would clean your tank and dissolve all of the sludge? - as it's still an oil base??

The only problem I encountered with Bio Diesel was its cost and location.  When diesel was 75cents per gal bio diesel was $5 a gallon!!  Just couldn't get myself to even buy 5 gals + the cost of the container.  Also, it's hard to find.   Guess if I had a friend that worked at McDonald's, I 'd get it a whirl.  

[Terry Forshier]

Taken from a marine biodiesel website. (cut and pasted) if anyone is interested.Terry


Information for Boaters:
Biodiesel for Marine Engines

What is Biodiesel?  Biodiesel is an alternative fuel for diesel engines processed from soybean oil and other vegetable oils or recycled cooking oil.  Biodiesel is sold in California as a diesel fuel additive for recreational boats.  There are currently three Biodiesel producers marketing in California:  NOPEC Corp. (Florida) selling "BioBooster" in 5-gallon containers at 12 stores and docks, AG Environmental Products (Iowa) selling "SoyGold" fuel docks in Southern California and PMC/ Griffin Industries who are offering pre-mixed blends of biodiesel for marine and transportation applications.

How do I use Biodiesel?  Biodiesel is sold in 5-gallon containers at stores and fuel docks so it can be poured directly into to your fuel tank (it mixes readily with regular  petroleum diesel # 2) to create blends of up to 20%.  Add 5 gallons of Biodiesel for every 20 gallons of regular diesel fuel.  Tanks should be kept full, particularly in winter, to reduce moisture condensation.  Biocides are recommended to inhibit the growth of bacteria.  Commercial biocides are available at local marine supply stores.  Follow directions for their use carefully.

What can I expect from using Biodiesel or its blends?  At a 5% blend, Biodiesel can restore the lubricity properties of diesel fuel sold in California before late 1993 when California Air Resources Board (CARB) mandated fuel changes.   At 20%, there will be an noticeable reduction in smoke, soot and burned diesel odor from the engine's exhaust.

What were the CARB fuel changes?  In 1993, the US EPA and the California Air Resources Board (CARB) mandated formulation changes for petroleum diesel fuel to achieve reduced emissions of sulfur oxides, carbon monoxide and unburned particulate material (soot).  These changes have led to allegations, due to the reduced lubricity of the fuels, of injector pump failure and fuel leakage from failing O-ring and injector pump seals. Blends of Biodiesel with reformulated petroleum diesel have been shown to improve the efficiency of combustion of the petroleum (in addition to diluting the noxious compounds) and thereby reduce emissions of sulfur oxides, carbon monoxide and particulates.   There are important mechanical advantages as well since the biodiesel provides high lubricity to protect against wear in the fuel and injector pumps.  Elastomeric properties of the original (pre-1993) diesel are restored by the solvent action of the oxygenated fuel allowing the engine seals, pump O-rings and gaskets to swell for tighter fits designed for use with the original formulation.

Can I use more than a 20% blend?  In Europe and on the east coast, Biodiesel is marketed as an alternative fuel to replace petroleum diesel in marine engines.  There are considerable environmental and aesthetic benefits to using the biodiesel in higher concentrations or as a "neat" (100%) biofuel.  However, by state law in California, and warranties provided by the suppliers, biodiesel is marketed and sold as an additive for marine diesel engines to be used in blends up to 20% (5 gallons to every 20 gallons of regular petroleum diesel # 2).

What other changes can I expect from the use of Biodiesel?  Besides the reduction of exhaust odor, higher concentrations of Biodiesel should also reduce the amount of soot being deposited on the boats hull.  Your diesel engine should run smoother, particularly at low rpms, and it may start easier.   Being an oxygenated fuel with no crude oil contaminants, the Biodiesel itself burns cleanly and it further improves the combustion of the petroleum fuel.

Do I have to modify my engine to use Biodiesel in my boat?  No, Biodiesel mixes with your regular diesel fuel as a blend and should require no changes to your engine in blends up to 20%.  Biodiesel (in high concentrations) can affect old rubber fuel lines and also clean the inside of old fuel tanks, causing the released sediment to clog fuel filters.  Of 100 boaters surveyed this year, only 6% reported any problems at all (mostly due to old fuel lines and dirty tanks affected by high concentrations of Biodiesel).  87% of the boaters had no problems at all using Biodiesel, even at high concentrations (50% of the boaters surveyed used Biodiesel from 50% to 100%).  The following precautions are recommended for boats with older tanks and engines:

1.  Start off with clean fuel tanks and clean fuel before adding biodiesel.  Old fuel tanks that have not been kept "topped off" through the winter or have much turnover of fuel (standing long periods of time) are highly susceptible to growth of diesel-degrading microorganisms.  Sediments and slime from the deteriorated fuel may be released from the tank by Biodiesel.

2.  If you are not sure, inspect your fuel filters regularly for signs of sediment accumulation.  Moisture condensation in diesel tanks will promote the growth of bacteria and mold (not "algae") that will eventually foul fuel filters.  In extreme cases, your engine might stop, so be very careful to monitor the filters and change them on a regular basis to be safe.

3.  Monitor rubber fuel hoses, filter gaskets and seals, and replace them as needed.  The solvent action of the oxygenated Biodiesel can slowly deteriorate old rubber hoses, gaskets and seals. Again, these effects appear to be limited to higher concentrations of Biodiesel (e.g., 50-100%) and are rare among older boat engines operating on 20% or less Biodiesel.  If a fuel line gets soft, replace it with USCG-approved grade A-l  fuel hose sold in stores.

Recommendations for Handling and Using Biodiesel

Avoid spilling Biodiesel into bilges, onto engine or on painted surfaces; clean spills up immediately with absorbent pads.  Rinse surfaces with mild detergent and water.
Biodiesel has been shown to degrade polysulphide rubber compounds used on decks.  To date, we have had input from users that spilling Biodiesel on teak decks utilizing polysulphide caulking has resulted in the deterioration of deck seams.  Spills which are immediately cleaned up with soapy water have not had the same impact on deck caulking compounds.

We have not seen or heard of any problems from boaters with their soft rubber engine mounts.  It can be extrapolated from other rubber compound incompatibilities, that exposure to rubber engine mounts could lead to degradation of the rubber compound and  failure of the engine mount.  As in other instances, cleaning of rubber mounts and painted surfaces exposed to Biodiesel is easily accomplished with warm soapy water.  Treat the Biodiesel as fuel, wipe up spills, wash off exposed surfaces and prevent any discharges of the product to the Bay.

How do I get more information?  Contact the marine sales department of the Biodiesel supplier by calling the toll free number on the product label.  For NOPEC BioBooster, call 888-BY-NOPEC (296-6732).  For AEP SoyGold, call 888-4 SOYGOLD (476-9465).   You may contact the National Biodiesel Board at 800-841-5849 (web site at www.biodiesel.org).

CytoCulture in Point Richmond, CA has recently published a "Technical Handbook on Marine Biodiesel" and "Survey of 100 Recreational Boaters using Biodiesel on San Francisco Bay".  These two reports, along with other technical documents pertaining to Biodiesel test specifications and current Federal/State laws may be reviewed on the CytoCulture web site at www.cytoculture.com/biodiesel.  For further information, contact CytoCulture at 510-233-6660.

[Footloose]

Guys,

Read paragraph seven from Terry's post.  It states that it can cause problems with old fuel line and claen fuel tanks causeing filters to clog with the sludge.

I guess caution is needed before using this product.

[Ron Hill]

Terry : Thanks for the rundown on bio diesel.  I suspect that the 6% that ran into problems would have had the same problems with clogged filters if they'd encountered rough WX where the fuel in the tank is REALLY stirred up.

From all of the posts on this site and articles in the Mainsheet tech notes, it's hard to believe that people don't heed the warning from other owners and change hoses/clean tanks?????? 
I've changed my fuel hoses twice since 1988!!  On boats that are 10 years and older, the outside of fuel hoses are starting to dry rot.  Take a section of fuel hose and bend it 90 degrees and if you see the cracking of the outside jacket - it's time to change the hose!