Fuel Tank Cleaning

[DavidPeckham]

Hi all, found a few posts relating to this from way back on the forum, anyone got any recent experience doing this with a jet wash and wet vac? (is it possible - lot's of tricky angles!)  Could anything be added to water to dislodge stubborn deposits on the bottom??

 

Cheers for any suggestions!

 

Brian

[Tony Brooks]

If this is a typical leisure narrowboat without a tank access cover, then I doubt it would be worth the effort. Even if you have a bad case of bug, it is unlikely to shift all of it from the extreme corners, away from the filler. Different if you have a decent access cover.

 

I think in bad cases the yards seem to cut the front or back of the tank out to give good access, then use a steam cleaner, and finally weld the removed bit back in.

 

I am interested in why you think it is necessary, unless you have a proven bug problem that a strong biocide won't shift.

 

 

 

[DavidPeckham]

Thanks - got some problem with the breakdown of very old/mixed fuel that's caused a problem with the pump and injectors, since replaced the injectors and had other parts cleaned. Person at the injector place is confused as to how all the gunk got through filters and has questioned what might be left in the tank. Worried about getting the same problem in a few months time.

 

 

[Tony Brooks]

9 minutes ago, DavidPeckham said:

Thanks - got some problem with the breakdown of very old/mixed fuel that's caused a problem with the pump and injectors, since replaced the injectors and had other parts cleaned. Person at the injector place is confused as to how all the gunk got through filters and has questioned what might be left in the tank. Worried about getting the same problem in a few months time.

 

 

 

I know some of the water emulsifier additives can produce a very odd "moussey" type deposit, while others additives have been blamed for producing a waxy coating that blocks the filters. As it passed the filters, it sounds like the mousse stuff.

 

Apart from cutting a trap in the front of the tank and making a cover that screws down onto a gasket via threaded holes, I think all you can do it to cobble up a bent copper tube (say about 3/8" i.d.) to clear plastic o the wet and dry so you can suck all you can out while searching with the bent tube, then add some diesel and rock the boat about, pump out and repeat until you just suck out clean diesel. I think RCR may have published something on so-called "sticky diesel".

 

Once done I would only use a biocide additive, if you what to use an additive, and clear the bottom of the tank of water & emulsified fuel at least once a year.

 

Once that is done

[Alan de Enfield]

1 hour ago, Tony Brooks said:

Apart from cutting a trap in the front of the tank and making a cover that screws down onto a gasket via threaded holes,

 

 

As had been said many times any boat built post 1998 is required to have an inspection hatch that allows access to the fuel tank 'internals'.

 

 

BS EN ISO 21487:2012

 

If there is a drain in a diesel oil tank, it shall be fitted with a shut-off valve having a plug that can be removed only with tools. Each tank shall have an inspection hatch of at least 150 mm diameter. The inspection hatch shall, as a rule, be located on top of the tank, but for diesel oil tanks it may also be on the tank side. There shall be access to the inspection hatch when the tank is in position.

[Tony Brooks]

3 minutes ago, Alan de Enfield said:

 

 

As had been said many times any boat built post 1998 is required to have an inspection hatch that allows access to the fuel tank 'internals'.

 

 

BS EN ISO 21487:2012

 

If there is a drain in a diesel oil tank, it shall be fitted with a shut-off valve having a plug that can be removed only with tools. Each tank shall have an inspection hatch of at least 150 mm diameter. The inspection hatch shall, as a rule, be located on top of the tank, but for diesel oil tanks it may also be on the tank side. There shall be access to the inspection hatch when the tank is in position.

 

True, but for may narrowboats totally ignored by the builders

[Alan de Enfield]

1 minute ago, Tony Brooks said:

 

True, but for may narrowboats totally ignored by the builders

 

 

Always makes me wonder what other corners have been cut ........................

[LadyG]

Oh dear, I can't find this inspection hatch,  it can't be a post 1998 vessel

 

3 minutes ago, Alan de Enfield said:

 

 

Always makes me wonder what other corners have been cut ........................

What, whenever you are buying another narrowboat?

[Midnight]

We have a boat club polisher which uses expensive filters but I think sucking the bottom of the tank with a 15mm copper pipe connected with tubing to a cheap B&Q drill pump does a good job too.

[Sea Dog]

13 minutes ago, Tony Brooks said:

 

True, but for may narrowboats totally ignored by the builders

Including mine! 

[DavidPeckham]

Cheers all (mines 1997) and thanks, Tony, details in those 'sticky' fuel stories sound very familiar!

[DavidPeckham]

Hi all, looks like the the only way I'm sure of getting rid of the sticky deposits at the bottom of the tank is to create an inspection hatch. Anyone got any experience/advice on this? I've contacted the BSC people to see if there's any existing specs/regulations.  Seems to be more serious than diesel bug and likely related to old fuel and increased biodiesel content causing it to breakdown (as mentioned here a few weeks ago).

 

Either way, cheers for all the help so far!

[Tonka]

My 1994 built boat has an inspection hatch in the fuel tank

[Tony Brooks]

58 minutes ago, DavidPeckham said:

Hi all, looks like the the only way I'm sure of getting rid of the sticky deposits at the bottom of the tank is to create an inspection hatch. Anyone got any experience/advice on this? I've contacted the BSC people to see if there's any existing specs/regulations.  Seems to be more serious than diesel bug and likely related to old fuel and increased biodiesel content causing it to breakdown (as mentioned here a few weeks ago).

 

Either way, cheers for all the help so far!

 

It rather depends upon how good you are at metal working. In the case of a typical narrowboat the tank is probably not baffled, so that makes it easier. It also depends upon how thick the tank metal is. It may be only 3 mm or so.

 

When I had to do it on thin galvanised tank on the hire fleet this is what I did.

 

Cut a disk of metal 2" larger than the hole that will be cut in the tank. This needs to be strong, so maybe 4 to 6mm

 

Cut a similar disk but with a hole in the centre the size of the eventual inspection hole. This does not have to be so strong and if the tank is thick enough to be tapped it is not needed.

 

Clamp both together and drill a ring of holes around both at the tapping size for whatever hexagon set screws you intend to use.d

 

Tap the ring and open up the disk holes to the clearance size.

 

Use the ring as a template to mark the face of the tank as close to the top as practical. If the whole tank is undercover, do it in the top.

 

Cut the inspection hatch and drill clearance holes in the tank

 

Drill two smaller holes in the ring opposite each other and drill and tap to accept small countersunk screws.

 

Transfer the hole as marks on the tank, clearance drill and countersink the small holes.

 

Make one cut right through the ring to allow you to work it into the inside of the tank.

 

Screw the hexagon sets crews into the ring and fix with a blob of weld, silver solder, braze, soft solder or Locktite stud lock

 

Work the ring into the tank via the inspection hole so the screws protrude and secure in place with the two small countersunk screws so their heads ar below the surface of the tank.

 

Make a gasket of suitable oil resistant material, push onto the protruding  screws and fit the disk on as well.

 

Using spring or star washers and nuts secure the plate to the tank. Tighten a little at a time on diagonally opposite nuts.

 

Pray it does not leak when filled (if you do it diligently, it should not).

 

If the tank wall is thick enough, a lot d the above can be omitted because you can use self drilling and tapping screws to hold the disk and gasket onto the tank.

 

It would probably be far easier to get a yard to cut a hole in the tank, clean it out, and weld the cut out section back in.

 

As an alternative, you could do what a hire fleet had done to my boat, that was fit another tank on the swim.

 

 

PS I think that you may be able to get the disk and ring from a decent plumber's merchant because they are/were used galvanised water tanks.

 

Edited September 27, 2023 by Tony Brooks

[Alan de Enfield]

59 minutes ago, DavidPeckham said:

Hi all, looks like the the only way I'm sure of getting rid of the sticky deposits at the bottom of the tank is to create an inspection hatch. Anyone got any experience/advice on this? I've contacted the BSC people to see if there's any existing specs/regulations.  Seems to be more serious than diesel bug and likely related to old fuel and increased biodiesel content causing it to breakdown (as mentioned here a few weeks ago).

 

Either way, cheers for all the help so far!

 

There are regulations in the RCD / RCR and any boat built post 1998 should have one fitted, or, it is non-compliant.

 

Here is what the rules say :

 

 

BS EN ISO 21487:2012

 

"If there is a drain in a diesel oil tank, it shall be fitted with a shut-off valve having a plug that can be removed only with tools. Each tank shall have an inspection hatch of at least 150 mm diameter. The inspection hatch shall, as a rule, be located on top of the tank, but for diesel oil tanks it may also be on the tank side. There shall be access to the inspection hatch when the tank is in position".

 

Other Fuel tank requirements :

 

 

Fuel system and fuel tanks

 

ER 5.2.1 The filling, storage, venting and fuel supply arrangements and installations shall be designed and installed so as to minimise the risk of fire and explosion.

 

ER 5.2.2 Fuel tanks -

Fuel tanks, lines and hoses shall be secured and separated or protected from any source of significant heat. The material the tanks are made of and their method of construction shall be according to their capacity and the type of fuel. All tank spaces shall be ventilated. Petrol shall be kept in tanks which do not form part of the hull and are:

(a) insulated from the engine compartment and from all other source of ignition;

(b) separated from living quarters. Diesel fuel may be kept in tanks that are integral with the hull.

 

Harmonised standard: BS EN ISO 10088:2013 Small craft - Permanently installed fuel systems BS EN ISO 21487:2012 Small craft - Permanently installed petrol and diesel fuel tanks

 

The requirements for installation of a fuel system on a boat with fixed fuel tanks are given in the harmonised standard BS EN ISO 10088 Permanently installed fuel systems and BS EN ISO 21487:2012 Small craft - Permanently installed petrol and diesel fuel tanks.

The requirement for petrol fuel tanks to be ‘insulated from the engine and all other sources of ignition’ is deemed to be complied with if

a) the clearance between the petrol tank and the engine is greater than 100 mm and

b) all electrical parts on the engine which could create a spark, and any other electrical components in the engine/fuel compartment, are ignition protected. To ensure that these components are ignition protected the boat builder should use a petrol engine that complies with BS EN ISO 15584 Inboard petrol engines - fuel and electrical system components (the engine manufacture should provide this confirmation) and for other parts, e.g. blower fan or electric bilge pump, use only components that have been CE marked in accordance with Annex II 1. The clearance between a petrol tank and any dry exhaust components must be greater than 250 mm, unless an equivalent thermal barrier is provided. For diesel engine installations, the engines used should comply with BS EN ISO 16147

Inboard diesel engines – Engine-mounted fuel and electrical components to ensure that the fuel components fitted on the engine by the engine manufacturer are safe. The engine manufacture should provide confirmation that the engine complies with this standard.

Fuel hose used in the system must be fire resistant if used in the engine compartment and Where fuel hose is used the standard requires that only fire-resistant hose to BS EN ISO 7840 may be used in the engine compartment. Such hose should be stamped to indicate compliance

[Tracy D'arth]

It does help if you cut an elliptical hole!   🕳️

[DavidPeckham]

Comprehensive instruction there! (with some added entertainment along the way...) need time to sit down and go through it.

 

As ever, cheers all!

[Alan de Enfield]

My 3x diesel tanks (1x 1000 litre and 2x 900 litre) have plastic inspection / cleaning hatches. (all in the same boat)

 

The boat has passed every BSS inspection without comment.

 

Very simple to fit as the threaded flange simply screws or (no nails stuff) over the hole in the tank, and the cover then 'threads' onto the top of the flange.

 

(I also have the same 'hatches' on the fresh water tank, the Grey water tank and the black water tank)

 

Picture is of the black water tank.

 

[DavidPeckham]

Cheers Alan, will try sourcing something like that.

 

Brian

[Quattrodave]

20 minutes ago, DavidPeckham said:

Cheers Alan, will try sourcing something like that.

 

https://www.tek-tanks.com/product-category/tanks/tank-accessories/inspection-hatches/

 

Edit:

Cancel that, its not rated for fuel.

 

Edit edit:

Correction, some are rated for diesel...

Edited September 27, 2023 by Quattrodave

[ditchcrawler]

5 hours ago, DavidPeckham said:

Hi all, looks like the the only way I'm sure of getting rid of the sticky deposits at the bottom of the tank is to create an inspection hatch. Anyone got any experience/advice on this? I've contacted the BSC people to see if there's any existing specs/regulations.  Seems to be more serious than diesel bug and likely related to old fuel and increased biodiesel content causing it to breakdown (as mentioned here a few weeks ago).

 

Either way, cheers for all the help so far!

I have known Alvecote marina to do this

[Tony Brooks]

1 hour ago, DavidPeckham said:

Cheers Alan, will try sourcing something like that.

 

Brian

 

Be very wary, Alan seems to have his in the top plate of the tank, but on a narrowboat where it would be exposed to rain etc. I don't think that is ideal. having suffered endless trouble with the plastic raw water strainers of several brands, I would be wary about any screw on  plastic cap type device, but that may just be me.

[Tracy D'arth]

Would a plastic inspection port be suitable for fuel; long term, or acceptable for BSS? Especially it had to be in the side of the tank as in most narrowboats.

[Tony Brooks]

Just now, Tracy D'arth said:

Would a plastic inspection port be suitable for fuel; long term, or acceptable for BSS? Especially it had to be in the side of the tank as in most narrowboats.

 

I suppose that will depend upon whether it is marked with suitable fire and fuel resistant rating. If not then probably no.

[Alan de Enfield]

11 minutes ago, Tracy D'arth said:

Would a plastic inspection port be suitable for fuel; long term, or acceptable for BSS? Especially it had to be in the side of the tank as in most narrowboats.

 

As I said -mine has passed a number of BSS examinations.

 

Yes it is on the top of the tank but it would still be 'watertight'if mounted horizontally. They are used on ocean going boats and seem to keep the sea out of lockers.

 

I was simply using it to show a POSSIBLE  alternative. I'm sure there are diesel resistant seals that can be used.