Fuel Tank Cleaning - Mainship 390

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M T Nest

Member
Joined
May 13, 2021
Messages
6
I need to have my fuel tanks cleaned on a Mainship 390 with single engine. The company I contacted thinks they may have to cut service ports in the tanks. Anyone else have their tanks cleaned? How did they access the tanks?

M T Nest
2002 Mainship 390
 
MT
It is not uncommon to have ports installed. But, what issues are you having that requires tank cleaning? Also, describe your current fuel filtering systems.
 
Thinks you need a cleanout port???? Get a borescope from Amazon. Inspect your tanks. You won't be able to see whole tank due to baffles but any sludge on the bottom might indicate a cleanout is a good idea. If so you would require ports. Not a huge project.
 
If you go the route of installing new clean out ports, install the largest ones possible.
 
Thanks for your response.

What I have learned is, I will need to add a service port, but only 1 per tank as they can work around the baffles.
 
I doubt that they can work around the baffles. The baffles usually only have small holes to allow the fuel to flow around them. Usually you have to cut an access port in each section of the tank.
 
Its a pretty easy job if there is access. I did mine myself. Seabuilt access covers have a good design and can go in the side.
 
I need to have my fuel tanks cleaned on a Mainship 390 with single engine. The company I contacted thinks they may have to cut service ports in the tanks. Anyone else have their tanks cleaned? How did they access the tanks?

M T Nest
2002 Mainship 390

You have the option to contact a different company and see what they have to say, but nobody on an Internet forum who hasn't inspected your boat can tell you if you need service ports in your tank.
 
MT
Again, what issues are you having that necessitate a fuel tank cleaning?
 
i also recommend the seabuilt ports. so easy to install and impressive construction.
 
Four thoughts for you:

1) I've often thought that I would install a tertiary (third) fuel filter IF I ever had problems...

Racor 30 micron > Racor 10 micron > to my CAT 3126's engine-mounted 2 micron.

2) I've often thought of installing one or two of these fuel polishing units:

https://www.jmesales.com/racor-p510mam-multipass-fuel-polisher-fuel-filter-water-separator/

Again... if I ever had problems.

3) But fortunately for us, we have never had problems with the fuel we have taken on. We completed our Great Loop, and have transited up and down the east coast without atypical fuel filter changes required. Maybe once a year?

4) I'm a big believer in these gauges, and I take a picture of the gauge at every weekly oil/engine check when underway. They have a "recording needle" so you don't have to be in the engine room to see what the gauge is reading while steaming along! https://www.racorstore.com/index.php/catalog/product/view/id/12102

The forward end of the fuel tanks, on the bottom, is the "leveling" fuel line that lets the tank levels equalize. That would be a good line for a "polishing service guy" to tap, then they could send the return / cleaned fuel into the normal fill tank outside.

If you know your Mainship actually NEEDS the tanks cleaned out, that would surprise me.

In that case, there is more to your story that we would all like to hear about!!!

Ray
 
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