algae on diesel tanks...to filter or to polish?

My mechanic says not to polish, will be better off by installing two (twin engines) of the redundant big racors, I'm sure that's the best way to go, but at $1,200 each I'm looking at spending aprox. $4,000 when you include instalation. I was thinking to buy a couple of the large single Racors, one per engine and leave the old small units for redundancy, if I can make this work I can probably get it done for under a thousand bucks and still have a redundant system for each engine..... And of course there is the question of professional polishing... thoughts out there??

Assuming your boat has been working OK with current filters, you could go in series with a racor 900 30 micron in front of your current filter. 30 u will pick up most of the crud and the filters are only $10 to replace (Keep 4 per engine minumum on the boat) it will also pick up the water.

This will not allow you to change filters underway but unless you are making really long trips or can't get to them underway then you can probably do without.

BTW... this is NOT redundancy unless you put them in parallel... I prefer serial. BTW... spend the extra couple bucks and buy the guage for the top. It will help prevent you from filling them up with gook and not knowing.

map wrote:

Redundant Racors, valved such that you can isolate either one is a great setup. Nothing worse than having an engine die of fuel starvation while underway and having to replace a filter in 6 - 8 footers. The filters need to be of the proper size for the fuel flow however. Too small will restrict flow, too big will not filter properly.

I have a boat that spent over a year tied up at a slip in Florida without being run enough to refuel. Knowing it was going to sit for a while, I added the recommended amount of fuel conditioner that included algaecide at the last refueling. When I finally prepared the boat for a return trip from Florida to MA, I had the fuel (500 gallons total) professionally polished as a precaution. Turns out it really wasn't bad ... I could have easily made the trip with out fuel problems.

Eisboch

If you decide you need to polish, and may need to do so in the future, you can build your own polishing system for what it costs to have it done once. I built one like this and use it as a preventative measure, since I carry 700 gallons, which can be a year or two worth of fuel for me. See: http://www.gulfcoastfilters.com/fuel_polishing.htm

The heart of the system is the GCF filter... you can use a continuous duty Walbro pump to pump the fuel through there.