Diesel Tank Cleaning?

[bruce smith]

baffles are good, until they are not.
how ya clean around those baffles?
If money is no object, make a new tank, with no baffles. And a drain on the bottom.

[DeepFrz]

Baffles are put in for a purpose. They may complicate cleaning but they do stop the fuel from sloshing around to much and over-stressing the the tank. I would not recommend you put a fitting at the bottom of a fuel tank.

[bruce smith]

My tank is 33 years old, 40 gallons, (plywood n epoxy) no baffles, double angle at the bottom, with a drain.Fuel pick up is a few gallons above the bottom.
Before launching, I dump a quart of fuel , from the drain into a glass jug. A "bloom" of goo plops out.
No one inspects my private yacht. If it were a gasoline tank, then sure, no drain on bottom.
I think the most common problem boats have first time offshore is overwhelmed fuel filters.
Wood tank is quieter, and does not condense water inside.

[Delancey]

I am waiting for a call back from another tank cleaning service but I think I have already made up my mind in favor of installing inspection ports, and the reason why isn't to get the tanks clean. It's to be able to visually inspect the interior of the tank for corrosion.

I have attached a photo of an area of corrosion on the outside which I have to get fixed. Thinking about this prompted me to consider how much it would suck to go through all this trouble only have a pin-hole leak show up in six months because I just assumed the interior was fine, just dirty.

I read on a different forum somewhere once about someone who had a leak in their aluminum tank that was caused by a stainless screw that had fallen in and slowly eaten it's way through the bottom.

Someone earlier on this thread suggested NOT to use aluminum screws because they were too weak and to use SS instead. Personally my money is on aluminum screws that are sized appropriately so as to not break.

The Sea Built system, which comes in a stainless or aluminum version, uses a backer ring and double gaskets isolates the tank access plate so that you could use stainless it you wanted. They do however recommend using the aluminum version for aluminum tanks. They use Buna-N rubber for gaskets.

Given the fact that there is obvious corrosion on the outside I think I would be a fool not to ensure the inside is sound. I'll post some pictures in a week or so once the job is completed.

[rebel heart]

Originally Posted by bruce smith

baffles are good, until they are not.
how ya clean around those baffles?
If money is no object, make a new tank, with no baffles. And a drain on the bottom.

Maybe for a small tank, but if you're talking about more than a hundred gallons that's some serious sloshing without baffles.

[bobconnie]

Good lord ! they even have baffles in large out board tanks ! why would anyone want a sea going tank for diesel without them!! think about the weight of 50 gals of diesel sloshing around in a 10 ft or bigger sea way !! then ya know why theres baffels in em LOL And thats another reason they are so hard to remove ! they need to be secure !!

[bruce smith]

My plywood 40 gallon baffelless tank, which has 60,000 sea miles on it, is also quiet!
That is def looking like a new tank is in order.
I know most folks will reject the idea of a plywood fuel tank like mine.
But it has many advantages over metal, glass or plastic.

[The Way]

Originally Posted by Delancy

I am waiting for a call back from another tank cleaning servic.

Before the process described in post #12, I had a dockside service that spent four hours cleaning my tank and got out a TON of crud. We constantly moved the jets, rocked the boat, etc. The fuel was totally clean at the end of the four hours.

Even so, when I removed the tank a few weeks later, there was still crud in the tank.

I think the effectiveness of a dockside service depends on the shape and baffles of the individual tank. Sometimes they just can't reach everywhere. Also, of course, they don't use solvents or cleansers, just diesel fuel under pressure, which can't seem to handle serious buildup.

Since your tank is out, just do the cheap manual processes several of us have described and save $300.

Fair winds,
The Way

[thinwater]

a. Much depends on the shape of the tank. The OP's tank is flat and MUST have baffles. A deep tank might not.

b. Baffels make cleaning challenging, but they reduce the chance of stirring stuff up or getting air-lock.

c. In a perfect world, a small opening (1- to 2-inch) in each chamber would allow a power washer, and then a larger port in the deepest chamber would allow pumping out when cleaning. Sometimes a bent tip on the power washer makes all the difference. 15 degree tip, no quick release on the tip.

Boat owners make this seem like great tramma, but in the chemical, petroleum, and transportation industries this is daily business, generally with hazardous materials.

[Cheechako]

Someone earlier on this thread suggested NOT to use aluminum screws because they were too weak and to use SS instead. Personally my money is on aluminum screws that are sized appropriately so as to not break.
It was me. Personally , I just dont see a corrosion issue on a tank lubricated with diesel and on the top of the tank. But, good alum screws (not from the local hardware store!) are likely fine if not extracted too many times and you have enough finesse not to break them. OTOH, you could end up with a seeping gasket, (especially putting large insection ports on a .090 thick tank) smelling up your boat etc and be tempted to "just try a little more tighter...!"
that's not a difficult tank, and if you are seeing the corrosion I see on the bent corners (is that the top!!?) Then get it replaced for the work involved in redoing it. Dont be pennywise and pound foolish. Do a good job and move on to the next project.

[rebel heart]

Originally Posted by The Way

Before the process described in post #12, I had a dockside service that spent four hours cleaning my tank and got out a TON of crud. We constantly moved the jets, rocked the boat, etc. The fuel was totally clean at the end of the four hours.

Even so, when I removed the tank a few weeks later, there was still crud in the tank.

I think the effectiveness of a dockside service depends on the shape and baffles of the individual tank. Sometimes they just can't reach everywhere. Also, of course, they don't use solvents or cleansers, just diesel fuel under pressure, which can't seem to handle serious buildup.

Since your tank is out, just do the cheap manual processes several of us have described and save $300.

Fair winds,
The Way

That's my whole argument against fuel polishing.

[Roy M]

This might be a good opportunity to build a plywood tank with baffle, inspection plates, and all the bells and whistles, and avoid the chance of future pinholes in the aluminum welds. My tank is 55 gallons, West System with graphite powder to make it look cool.

[surfmachine]

Nice black ply tank mate!!! I let my twin separ filters polish the fuel for me, have used a outboard priming pump on a long suction hose to get in through the inspection port to the low part of the tank and suck up dirty fuel/water, until all clean.

Never had a filter block yet, the fuel in indonesia is like mud, diesel in thailand is a lovely clean, orange colour, malaysian fuel looks like piss, but is clean!!

Cheers from Keith....

[goboatingnow]

Get the tank steam cleaned., it's the best method

Dave

[Cheechako]

fuel polishing takes out all the loose muck real well. I wouldnt go offshore in an old boat without it. It likely wont remove hard-ish residue from the tank though, but that may not be a problem.