A27- Fuel Tank Removal & Install

[JT48348]

Interesting reading this diesel bug thing. I read that Apparently less than .01% of the debries left in a tank are from the 27 kinds of micro organisms that habitat in the water interstate. The black stuff at the bottom of the tank is largely paraffin and asphalt, basically the decomposition of the diesel fuel over time. The crud that accumulates in filters and elsewhere is just diesel fuel broken down into some other form.

I may try the gasoline soak, but I see no real solution other than access ports and a deep cleaning. Best to start from scratch.

[Beta Don]

My tank was cleaned around 2000 and the 40 or so gallons of diesel they took out of it was 'polished' and put back in the tank, where it's been 'resting' for at least the last 15 years. I didn't want to take a chance with old diesel in my new engine, so I pumped it all out. Looking at it, I'm 95% sure it would have filtered and burned just fine - No sign of any black particles in it at all, which leads me to believe they must have treated it with a biocide when they put it back in the tank. I wiped the bottom of the tank with a white cloth and got . . . . nothing

I have always used Hammonds BioBor in the tank of every diesel boat I've ever owned. Don't use it in the truck, nor in my Kubota diesel garden tractor, but if I have any diesel which isn't going to be used within a year or so, I treat it with biocide. I've never had an 'algae' problem, but I've seen several tanks which were largely taken over with the stuff, so if fuel is going to languish in your tank for a year or more, a good treatment can prevent a real mess

Using biocide on my last sailboat, I went 4 or 5 years without needing to change the filter element in my Racor 500 - I had a vacuum gauge attached to it to monitor the cleanliness of the filter element and it never indicated the need for a new filter element . . . . so I didn't change it. I like the Racor 500 series filters because you can buy most any element you want for them (2, 5, 10, 20 micron) and the elements are cheap - Less than $10 depending on where you get them. It's a bigger filter than a small diesel really needs, but it's a very good water separator and because it has a clear bowl, you can see what's going on. I found the one I put on my A27 on eBay brand new for $75. Maybe the steal of a lifetime

Don

[sail149]

I think I would rather do the best job I can cleaning with gasoline , which evaporated slower than acetone and is cheaper by far, them spend time and money on a second filter with a flip flop ball valve and vacuum gauge, same as the charter boats have rigged up. One bad batch of fuel and your cleaning work is for nothing.

As an aside, we have an outside 1500 gal fuel oil tank for heating oil and the guys just asked me if I had any kind of pump to get water out of the bottom as when they "dip" it in the winter the frozen water in the bottom gives them a false reading! I bet it does! Not sure why it dosen't get into the fuel line ( it feeds 5 oil heaters).
I lent them my oil changing electric pump......

[sail149]

Checking you photos, do you have the 6 cyl izsu engine?, does the fiberglass box make room for the longer engine?
Thanks for the photos of what's in there! I hate the ugly fiberglassed over tube , usually from the center of a roll of fiberglass. Pretty much useless at adding much strength ok for port-a-potty but that's about it! Nobody ever uses enough fiberglass over it to do any good.
W

[JT48348]

Negative I have the Nissan LD28. Not sure why I have the extra space from the fiberglass panel. Lot of room under my cockpit.

[Beta Don]

I *think* the fiberglass box gives extra length to accommodate the transmission on the 6 cylinder models. Whatever the reason is, it moves the fuel tank far enough aft that it doesn't leave room for the set of drawers in the aft cabin like the 4 cylinder models came with

Don

[JT48348]

Waiting on a weather window to begin interior painting, I started on cleaning my fuel tank for the A27. I plan to install three home made inspection ports in the top of the tank. Because there are two baffles separating the tank I chose three compartments.

I used a jig saw with metal cutting blade to cut the ports. The tank is robust and there was virtually no flexing.

The interior of the tank ended up being in reasonable shape. The brown and black gunk in the bottom of the tank was easily scraped out using an old epoxy fairing spatula. It appeared to be about the consistency of crumbled asphalt and coffee grounds. On the walls of the tank it was basically a thin film of oil/grease muck. No sign of organic life. At this point the tank was looking pretty good.

Experimented with cleaning using a steam cleaner, then Simple Green, then acetone. Hot water and simple green seems to work well although steam gets the corners. It will take a little work but the tank will clean up nicely.

[JT48348]

I know there's been lots of debate about Loch Ness, Crop Circles, and the Diesel Bug. I prefer science as a candle in the dark, so while I mucked about with the tank I told my apprentice to fetch her Junior Science Lab Microscope and her goggles and get ready for the First ever Albin 27 Science Fair Experiment.

Topic: what is the muck in the bottom of the tank and are there any "bugs" there or amorphous fungi organisms noshing on diesel sludge?

Well, let me say, first it looks, feels, smells, and tastes like dirt. Or broken asphalt. Or diesel coffee grounds with no coffee.
I told my apprentice to load a slide and examine the substance under the microscope. "What are we looking for?"

My apprentice looked at me like I was stupid, as I tried to explain the various arguments in favor of paranormal diesel fungus. I recounted tales of mysterious substances "growing" in diesel drained into coke bottles in sunlight. Apprentice was not impressed and quoted Penn & Teller. "BS- be skeptical!"

I had the apprentice check the microscope twice. Myth Busted. The muck is petroleum by product and not organic. Science tells us less than 1%mass is organic. There you go.

[JT48348]

I was feeling arrogant and emboldened having proven that my muck was just normal diesel sludge. The tank would clean up nice. The welds all seemed good. The hatches would work fine.

I scraped a little on the outside of the tank and realized I might even etch prime the aluminum and spray the exterior white just to match my operating room motif.

But then I on closer inspection I noticed a small spot of corrosion no bigger than a dime. And I poked my eyeball right up to a pin hole. Total buzzkill.

Now I know why there was diesel in the bilge when I bought the boat. I thought it was just loose fuel line connectors. Curse you PO- you did me dirty again. There's a pinhole in the bottom of the tank! And it didn't get there overnight.

[JT48348]

Tank cleaned. Ended up going with simple green after steaming the corners. Then flushed with acetone which worked excellent;the exterior was cleaned with bar keepers friend and a scouring pad.

Turns out there's 3 pinholes all in one corner. I've located a welding shop that repairs tanks. They will even do a pressure test when done. So I went ahead prepared the hatch covers.

The search for a new after market tank was fruitless the A27 73 gallon tank was a custom design from AFP which is no longer in business. The tank is approx 38"x32"x14" with +2" for the 90degree fill tube height. Even you find a replacement tank it's approx +$200 shipping for a tank this size. I can imagine what it would cost duplicate this one. It's .09 aluminum with the welded baffles I'm going to inquire about a custom tank but I suspect this would be a $1000 item.

The three inspection hatches came out great. I sourced most of the materials from McMaster Carr. Basically the covers are 1/8" thick with a BunaN rubber gasket. The covers bolt right diwn on the tank. I used a self tapping drill bit for 10-32 bolts. A punch was used on the gaskets for the bolt holes.

Lesson learned: check your fuel pick up and return line, one of my 90degree fittings was partially clogged and other the alum pickup tube sheered off from age.

Waiting on fuel sending unit...

[Sprig1]

Looking good. What type of fuel gauge did you get? I need one to

[JT48348]

Sprig: I'm thinking about something like this:

http://www.defender.com/product3.jsp?pa ... id=2685703

Simple package deal. I need a sending unit and gauge. I think you can swap out gauges. Have you found a better combo?

[tego]

Joe, That's the assembly I went with and it works great! Everything swaps out perfectly and you can use the original wiring if it's in good shape (mine was). Ben

[JT48348]

Excellent thanks Ben. It's been ordered
Because of where my inspection ports are located my original manual unit hole is gone. Put a hole in one of the inspection ports? Or new hole off to the side?

[tego]

Definitely put it in the insp.port. You can install it easier, use ss nuts on the inside instead of tapping the tank metal or making a big backing plate. I used two of them since I have the twin 50 gal tanks outboard. It's the first time I've had accurate readings. Ben