Fuel Tank Cleaning
it is time...getting ready to clean the fuel tanks on Aorangi 47/047 and being the first time for us would appreciate any 'heads up' to eventual issues that need to be considered in advance (or during) so as to avoid surprises after (or during). We are in the Med. in a temperate climate just in case this makes a difference.
thanks a lot!
Ciao
Jayne

Dear Jayne,

It is no big deal, but!!! You have to take them out. Take care when you lift them out (if you do that) they are full of old and extreamley dirty sludge or what you call it! Use petroleum to clean it and install them again. Dirty job but not difficult.

Regards Cygnus Peña #20

Jayne

I would suggest a slightly simpler approach. Get a (hand) pump with the suction line small enough to fit through the sounding hole in the tank access hatch. The hole is closed by a screw cap. With this pump you can easily clean the tank also if you happen to get dirty fuel, not unusual in some areas.

Kind regards

Lars

Thanks for the suggestions, and glad to know that we can proceed without removing the tanks. We in fact were planning to pump the sludge out with a liquids vacuum but removing the bolted cap that houses the sounding cap. Better yet not to have to remove the bolted cap. Do you see a problem with using a liquids vacuum (on the dock) instead of a hand pump for some reason? don't want to create a hazard...
Ciao for now.
Jayne

Jayne

Assume you mean holding tank pumpout when you refer to liquid vacuum. Some care is needed if suction like that is used, the tank may implode if there is too strong vacuum, and it is suggested that an air channel, for example the filler line be open.

There is a small threaded plug on the tank inspection hatch, the plug closes the sounding hole, where the graduated dip stick can be inserted for a sounding - do you still have the dip sticks?

The sounding plug is located above the deepest part of the tank, therefore cleaning out is preferably done through the sounding hole.

 Best regards

Lars

Thank you Lars. We still use the original dip sticks yes. Which brings up another question. We have purchased gauges for the tanks, but have yet to install them, as I am so hesitant to have the hole drilled through the cover. Anyone done this, and if so would appreciate any suggestions, pictures, etc...
For now we'll proceed with the cleaning as recommended, and as long as the tanks are empty we'll see if it is wise to proceed.
Thanks again.
Jayne

Jayne

For making the holes for the gauges it is suggested that you remove the tank inspection covers and bring them to a machine shop. Be careful with the nuts and pin bolts for the covers, they are easily damaged by use of excessive force.

With the covers removed you have good access to the tank inside.

Kind regards

Lars

thanks Lars but just couldn't do it!
call it romance or call it good sense, I just couldn't have the hole drilled over the original capacity details on the tank cover . so we are dipping as always(and selling the gauges), but with a few new "level charts" noted during the cleaning to have a better idea of the rapport gallons to liters when nearing empty. ***noted the following after cleaning. to the lowest corner of tank:
using real gallon/liter=3.8
5 gallon mark=12 lt
8 gallon mark=22 lt
while I'm certainly (!!!) no mathematician it seems there is a 7 to 8 liter - curve once you go below 8-10 gallons.
while probably the only one without a gauge, thought just in case it could be useful to someone...

hoping we all had a blessed holiday I thank you for your input.
XXXO
Jayne