Fuel Anti-Fungal Agent

[seabum]

Hello, I've been a sailor all my life but only recently have my husband and I been able to afford a boat. I'm really enjoying learning more about systems. I've been reading through all our manuals and taking notes on suggested maintenance. We have a 50 hp Yanmar 4JH2E.

Question: the boat manual suggests adding an anti-fungal agent to the fuel "periodically". What might periodically mean? We sail year 'round on Puget Sound which has a relatively cool, moist climate. Does the anti-fungal agent last the whole time it's in the fuel or does it lose its strength over time? Being sailors, a tank of fuel lasts a long time.

Thanks for any help, suggestions, tips.

[Vasco]

I don't know about the PNW but now I always add Startron to my fuel in FL and the Bahamas. I used to just add a stabilizer when the boat was laid up for the summer but after having a major problem I now use Startron. It's not cheap but those that use it swear by it.
Star Tron Enzyme Fuel Treatment - HOME

[GordMay]

Originally Posted by Vasco

... I always add Startron to my fuel in FL and the Bahamas...
Star Tron Enzyme Fuel Treatment - HOME

In diesel application, add 1 fl. oz. of Star tron Diesel Additive for every 32 gallons of diesel fuel.

I used to use “Biobor JF”.
➥ Hammonds Companies | Biobor JF

“Treatment procedures
If system is badly contaminated, drain water bottoms. Water bottoms in storage tanks should be kept to a minimum. Good housekeeping is important in treating slime problems, but it is not a cure. Biobor® JF is used at 270 ppm in fuel to effect sterilization, and subsequently at 135 ppm to maintain fungi-free fuel (0.017 3 Fl Oz/US Gal, or 1 Oz to 58 Gal). Ideally, Biobor® JF should be metered. However, in the absence of metering equipment, Biobor® JF may be manually batchblended. If batch-blended, as in tank trucks or small aircraft wing tanks, Biobor® JF should be introduced while the tank is being filled and after the tank is approximately ½ full. This will ensure faster and more complete dispersion.”

[seabum]

Thanks, guys. This is very helpful.
Cheers

[Ziggy]

FPPF Killem is the only biocide approved by Yanmar. See here and here

[seabum]

Thanks, Ziggy. I guess I didn't do a very good job of searching the forum for the info I needed.

[noelex 77]

Grotamar has worked well for me.

[SPARK]

Has anyone tried iodine?
I have heard that this is used by some bio-diesel manufactures.

[Opie91]

Seabum,

As Gordy does, I use Biobor also.

It is used extensively in aviation where fungus and microbial life can be a serious problem. Besides clogging up your filters it can cause serious corrosion in aluminum fuel tanks. A sterilization treatment of Biobor will kill everything in the tank and a 6 month maintenance treatment will keep everything in good order.

If you would like to know if the fuel tank is contaminated you can use this:




Hammonds Companies | Biobor Hum-Bug

They are fairly inexpensive (around $20 USD) and work great.

Good luck

[mrohr]

Hi All: It seems that most, if not all,biogroth occurs at the interface between the heavier water at the bottom of the tank and the diesel above it. Once you succeed in getting every last drop of water out (another thread?)you must be careful as to not let any more in. Some change the o-ring EVERY time the filler cap is removed;but I just change it once a year and smear vaseline on threads and over cap every time cap is removed........solved 2 years of problems for me.

[cfarrar]

I seem to remember from an earlier thread, and from Practical Sailor, that it's best to use two different biocides (in order to target different types of bacteria / fungi). Does that sound right?

We alternate between two: Biobur JF and another one (maybe Bio-guard but I can't remember, and I'm not on my boat to look at the label).

[Opie91]

Cfarrar brings up a good point.

You have to be careful not to over treat your fuel. Biobor as with any biocide should not be over used. Microbial growths can become immune to almost any treatment if it not done properly. Most products will recommend a sterilization dose the first time to prevent this problem from occurring.