Fuel Tank Cleaning

[TortolaTim]

I'm planning on giving Ron's fuel tank cleaning recommendation a try. For anyone that has done this, how do you most easily get the acetone out of the tank when it's out of the boat? About the only thing I can think of is a drill pump. Is there an easier way?

[Noah]

Not an answer to your question but......when the tank is out of the boat and if tank is in good condition, I would consider installing one or two inspection ports.

[Robert Mann]

Last time I cleaned one out I used safety solvent and shook the tank around and then just drained it out of any available hole and moved on. I would think if you used acetone do the same and let it evaporate then slop some diesel around in it.  Remember acetone is flammable so don't take any chances, with it in liquid or gaseous forms.

[Ron Hill]

T/T : All you have to do is turn the tank and dump the acetone out of any hole in the top onto the concrete. Acetone has such a hi evaporation rate any residual will be gone in 5 minutes!!

Be careful about acetone around blacktop as it will eat it up!!

A few thoughts 

[Noah]

If no inspection ports I recommend you buy a cheap (Bluetooth to phone) borescope on Amazon. Then remove the fuel gauge sender and inspect the tank through there. You may not be able to see around the baffle but perhaps you can.

[Ron Hill]

Guy's : In most of the older C34 fuel tanks there was only one baffle. It is usually about half way in length short (about 8" tall with a cutout thru way at the bottom.

A few thoughts

[TortolaTim]

Cool, thanks guys. I pumped out the remaining fuel today and am going to remove the tank and clean it out this weekend. I bought a borescope on Amazon as recommended by Noah, so I'll be curious to see what it looks like inside there. I haven't had any fuel issues per se, I just figured that after 35 years, I should probably get it done while I had the tank near empty.

[Noah]

Good preemptive maintenance. My tank developed pin hole leak(s) a couple of years ago. Had to replace it.

[ewengstrom]

We had to replace our original tank in 2020 due to pin holes. Before I took it to the dump for recycling I cut it in half because...well...why not?!?!?
Here's the guts of the old tank clearly showing its construction.
I did put two clean out ports on the new tank on either side of the baffle. One was installed by the manufacturer and I added the second.

[Noah]

One thing to make sure:if there is a screen over the pick-up tube, REMOVE IT! Only causes problems.

[TortolaTim]

Got the tank cleaned out. This is the remaining half gallon of fuel before I cleaned it out. Good example of why this is a good idea to periodically do.

[waughoo]

I ended up with water in my racor and suspected a bad deck fill O-ring.  I used a hand crank fuel pimp for model airplanes and a model airplane "clunk" to pull out as much water as I could from the tank.  I managed to get about 16oz og  water out of the bottom.  I then used a fuel tratment to suspend the remaining water and burn it off.  Seemed to work pretty well. 

[Jim Hardesty]

On my winter maintenance list is to suck/pump/syphon a fuel sample from the bottom of the tank into a clear container.  Usually, a quart or two is enough to convince me that most of the settled water and yuck is out.  I've used a variety of pumps and suction devices the best for this purpose is one that disturbs the fuel the least.
I don't always do this every year, it's down on the list unless there's been a problem or the Racor shows contamination.  I did it every year for the first few years I owned Shamrock, found a lot of water at first, then less.  Doing this gives me a little more confidence that theirs's one less problem with the next season.
Jim

FWIW If I needed a new fuel tank would consider a drain on the bottom of the tank to make this easy to do.