Dual Racor System?

[phildogginit]

The crud (asphaltenes?) may have come from some organisms ? I cleaned the tank in 2021… that’s 34 years . I am very careful with what I put in the tank .

 

[phildogginit]

before I cut the tank open I tried washing it with solvents. No luck. It had to be manual removal with acetone and a rag

 

[Dave G.]

Best to clean the tank. I didn't do mine until "the crud" ate through the aluminum and it started to leak. Secondly if the crud in the tank is bad enough it's just a matter of when not if it gets stirred up enough to get sucked into the pick up. It will clog both those Racors when it does. Most of the sediment will be in the lowest part of the tank under the pick up tube. Clean out ports (clean tank) are a whole lot cheaper and much better peace of mind than Racors too

 

[ConchyDug]

Asphaltenes are precip from petroleum products not the microbial crude from water contamination. I've had it happen after mixing Jet-A(Free sump fuel from work) into my tank, bigggg mistake, incompatible fuels can cause the "tar". Also fuel additives can cause this as well.

 

[N.A.]

@phildogginit and @Dave G. --

Thanks! I have abandoned my plans for a dual-racor (since it won't fit in there anyway) and am going with inspection ports and new fuel line. Probably cheaper, and it is a root-cause fix which does seem better. Really appreciate the advice!



PS: Somewhere back in the thread, someone commented that I wouldn't need dual racors unless I had a much bigger engine. I think that means there was confusion about the point: the idea was not to run them both at the same time to reduce fluid resistance, but rather to be able to switch between them if one got clogged. That is a standard use model -- Racor even makes a pre-built-switchable system you can buy. Just doesn't fit in my boat.

 

[toddster]

FWIW, I did add the dual (small) Racor system, at the same time that I installed an aux fuel tank, and so far it has worked out pretty well. A new filter (or tank) can be selected just by rotating a handle. But... we're still sitting in the boat yard.

The electric Facet fuel pump I had in the spares locker turns out to work just fine for priming/purging filters, even though it is slightly more than a 3-foot lift from the bottom of the tanks. One thing this configuration lacks is the ability to change out the old filter while the engine runs - both filters have to be purged/changed at the same time. (Though only one is in use at a time.) I'd have to add a check valve (sketchy) or some other valve arrangement to make that work.

I zip-tied some of those hoses together, but there's no getting over that it's a little... intestinal. I had to leave long enough loops to open the panel. The Facet pump is almost invisible behind the hoses. (But this reminds me that drawer behind there is full of sheets for mattresses that are no longer on the boat, so I need to put those in the "to storage" box.)

Could also add another line to contain purgeate from the filter vents and send it to fuel return - currently have to catch it with a rag. But in planning, I forgot to account for feeding the diesel heater from this manifold. I've been sailing in warm waters so long it skipped my mind. So I've got to cook up some clever way that the purge pump can be used to fill a small header/day tank (there is room for one above the valve bodies) for the heater, without adding much more plumbing. Changing the heater to gravity feed will eliminated the all-night clicking of the heater fuel pump. I've (almost) gotten used to it, but when I'm talking to people on the phone, they'll ask, "what's that loud ticking noise?" Alternatively, I'd just move the heater pump in there and add another switch.

Or keep sailing south...

 

[Pete the Cat]

@phildogginit and @Dave G. --

Thanks! I have abandoned my plans for a dual-racor (since it won't fit in there anyway) and am going with inspection ports and new fuel line. Probably cheaper, and it is a root-cause fix which does seem better. Really appreciate the advice!



PS: Somewhere back in the thread, someone commented that I wouldn't need dual racors unless I had a much bigger engine. I think that means there was confusion about the point: the idea was not to run them both at the same time to reduce fluid resistance, but rather to be able to switch between them if one got clogged. That is a standard use model -- Racor even makes a pre-built-switchable system you can buy. Just doesn't fit in my boat.

I am the one who suggested you don't need duals unless you had a bigger engine. What I should have said is that the dual filter is almost standard on larger power boats that have no other means of propulsion. I used to do delivery work and the dual filter arrangement was common on dual engine power boat installations. I believe they had plumbing so that the filters could be changed while making way--often they were rigged so that you could isolate one engine (or not) and its entire fuel system (separate pickup sometimes from separate tanks) and still keep moving. A sort of important safety thing for larger, multi engine power boats with no other means of propulsion.

 

[bigd14]

The baffle should become apparent from welds or dimples. Tap the surface. I put an inspection camera in through the fittings to have a look.

One hatch is in one section , other in other. The seabuilt hatch is a great product.

I had to also drill holes in aft cabin berth cover to make room for the hatch bolts.

This project is getting closer. I’m debating merits of doing it in situ vs pulling the tank. Wondering if you can reach all areas with the tank in place and the two access ports as shown or can you only reach with the tank on the workbench? Also I assume those are the 6 inch plates with 4 inch cutout, right? I guess it would be easy enough to remove the tank once I get it pumped out, but sounds like major boat yoga may be needed. However, I’m sure it would be easier to install the ports in the relative comfort of the garage. Choices! I plan to custom fabricate my own hatches and will likely go with a 5 inch cutout and 7 inch plate.

 

[Christian Williams]

It's nice to get your arm, vacuum cleaner hose, etc. through the hole, which 6" allows. But maybe there's a size price to pay if buying the cover kits (I made my own covers) .

One of the new inexpensive iPhone scopes would be good to have for initial assessment of baffle location and degree of glop. insert through guage port.

Would be easier with tank on the workbench? I don't know why it would be, unless maybe work area on the boat is very constrained. Generally you just sort of clean with a rag on a stick where a hand cannot reach.

A GoPro camera makes inspection easy, once you have a hole made.

My most irritating issue was extracting and disposing of 30 gallons of existing diesel. Forbidden at the usual oil collection sites.

My project here.

 

[Dave G.]

I wouldn't pull the tank unless it's impossible to access the top in place. I installed an access port, cleaned, repaired leaks with epoxy all with tank in place. If I didn't need to epoxy the bottom of the tank it would have been a 4-5 hour job. The repair added another couple hours plus some wait time.

 

[Dave G.]

Also 5" may be a little small. Unless you have real thin arms of course

 

[bigd14]

Ok, I will plan on leaving the tank in place unless the spirit moves me when I get in there. It actually doesn’t look too hard to remove. I will inspect through the sender port before deciding on location and size of cleanout ports. I will be fabricating my own, so will have flexibility on size. I’ll experiment with some plywood first to see what works for my non-skinny arm and assuming that a smaller plate is less liable to leak will go with the smallest reasonable size.

There is a chance that the tank will not harbor much gunk, I think it was cleaned in 2011. Regardless, the fuel fill hose needs replacing and I want to be able to see what’s in there.

I plan to empty the tank into some clean new 5 gallon buckets with lids by using a drill pump or fuel transfer pump attached downstream of the fuel filter. Currently the fuel looks pretty clean and there is no water collected in the filter. Hopefully I can just pump the filtered diesel back to the tank once it has been cleaned out. If the diesel looks gnarly I can take the buckets of it to the local transfer station that has a free hazmat disposal.

 

[bigd14]

I can’t leave well enough alone and pulled the tank. It will be easier to work on it at home. Once I figured out the trick to removal was angling it in a certain direction it came out easily. A PO had done a nice job of installing supports beneath the tank. The fill hose is definitely original and showing cracks and the heater supply hose is leaking somewhere so this is an important job. Looks like the strut was replaced or rebedded as well. Also a nice detail with the embedded aluminum plate the tank hold down bolts screw into. I will probably paint this area with BilgeKote to prevent any future diesel spills from saturating the fiberglass.

Removal of 22 gallons of diesel was the hardest part of the job. I used a cheap 12v diesel pump and connected it to the existing filter so the diesel is nice and clean and can be reused. It will be interesting to see how the tank looks.

 

[bigd14]

Finally cut open the tank and found significant gunk, some of which appears to have been vacuumed into the filter, so I will be replacing the element. This is turning into quite a project due to the top of the tank being uneven and wavy, requiring some unique solutions which may or may not work. I’ll post details soon.

 

[Dave G.]

due to the top of the tank being uneven and wavy

Yeah, part of the problem is these tanks should have been thicker gauge to begin with. I see you already have holes for the port cover, did you buy a premade port ? I made my own from 3/16" aluminum predrilled holes in it and then fastened it to the tank with a gasket & permatex using sheet metal screws. If you use sheet metal screws do not use a power tool to tighten it will strip the tank material easily, hand tighten only. The premade ones usually have a clamping ring on the inside that should flatten and seal the tank I think. That tank looks pretty bad, really curious how the bottom looks when you get that clean. Since you have it out you can point a work light at the outside of the bottom and see how many holes the corrosion created. Swiss cheese probably

 

[Christian Williams]

Yes, that was a huge buildup of gunk. Timely intervention.

 

[bigd14]

I see you already have holes for the port cover, did you buy a premade port

I am making my own similar to the Seabuilt hatches but running into some difficulties. I have additional parts on the way from McMaster-Carr and I’ll post details as I get further. I sure hope no pinholes reveal themselves. I have heard of people adding an epoxy liner to the inside of the tank, but I am not sure how to do it. Would that be recommended as a preventative measure?

 

[bigd14]

Another question- although I have filtered the diesel through the primary fuel filter, should I re-use it once the tank has been cleaned? Will that simply reintroduce the problem back into the tank? I don’t know enough about the chemistry/biology/sciency reasons for why the fuel actually goes bad.

 

[Dave G.]

I have heard of people adding an epoxy liner to the inside of the tank

I did that a few years back and worked well. I used West Systems epoxy and a layer of fiberglass, more epoxy. I honestly don't remember which exact one I used but the people at West were very helpful with step by step instruction and exact products to use. Mine was an area of approx. 6x10" in very lowest portion under the pickup. Definitely a viable option in my opinion. Cleaned thoroughly with mineral spirits roughed up the area with 80 grit paper cleaned again with acetone. Then epoxy, lay in fiberglass, then more epoxy. Prep is the key as always to assure the epoxy gets good adhesion to the metal. I did mine without pulling the tank so the "yoga" factor was in play . Probably had 15-20 pinholes and the surrounding metal was very fragile I overlapped far enough to get to solid areas and as it was right up against the forward vertical side of the tank I folded it up the side a couple inches too.

 

[Dave G.]

Another question- although I have filtered the diesel through the primary fuel filter, should I re-use it once the tank has been cleaned? Will that simply reintroduce the problem back into the tank? I don’t know enough about the chemistry/biology/sciency reasons for why the fuel actually goes bad.

Does your primary have a water separator ? If so and the fuel is relatively recent I would reuse with a suitable fuel additive to be on the safe side. That sludge took 38 years to build/grow . I looked in my tank 3 years after the repair thinking it would need a clean and it was clear as a bell. I use a fuel additive(Power Service "Clear Diesel") and highly recommend regular use of whatever additive you decide to use.