Visitors to Cherry Ripe are now warned to wear shades when going anywhere near the fuel supply. Since spending most of Friday morning polishing the fuel thus:
...we now have easily the shiniest diesel for miles around. Quite pleased with the project, about £50 for the bits and quite easy to get it working. The priming bulb did block a few times at first when large lumps of crud came through, but it is now set up to be easily disconnectable and the use of a pokey thing clears it out. 3 hours at 1.4 l/min means the 90 l or so of fuel in the tank has had a good seeing to, and certainly the filter was gratifyingly black at the end of the process.
It was relatively easy to organise when there is a nice big inspection hatch on the tank but probably adaptable to many tank arrangements. If anyone in the locality would find it useful to follow our example the machine will be available for loan.
Looks a great idea. Is that one of those electric clicky type lift pumps? (tick tick tick style)
I had always assumed that most of the unshiney diesel sits in the bottom of the tank. I made a 2 litre bottle with two tubes. One to suck (mouth powered), the other much longer with a straight stiff length I probed through the filler cap, working along the tank bottom, sucking the crud up into the bottle. Cost less, but maybe it missed suspended crud?? Is there such stuff?
ps, where in the boat is this shot? (R38 might be quite different to R32), is it forward?
Geoff.
"Contender" Rival 32: Roseneath in winter, Mooring off Gourock in summer.
mm5aho wrote:Looks a great idea. Is that one of those electric clicky type lift pumps? (tick tick tick style)
I had always assumed that most of the unshiney diesel sits in the bottom of the tank. I made a 2 litre bottle with two tubes. One to suck (mouth powered), the other much longer with a straight stiff length I probed through the filler cap, working along the tank bottom, sucking the crud up into the bottle. Cost less, but maybe it missed suspended crud?? Is there such stuff?
ps, where in the boat is this shot? (R38 might be quite different to R32), is it forward?
It's in the after cabin, tank is under the cockpit and the 2 quarter berths are under the cockpit seats & gas lockers. It is indeed one of those ticking electric pumps. The point of the more elaborate process is to try and get more non-fuel items out of the supply, just sucking at the bottom of the tank will inevitably stir up stuff and you only actually catch a fraction of what's there. Recirculating the fuel through a filter means that there's a good probability of getting a significant proportion of the sediment out, thus mitigating the risk of (another) major blockage in the supply pipe.
Not sure if I am completly grasping the concept of fuel polishing.
Does it not get polished while going through the filter while in circulation to a running engine? or is this not adequet enough?
On my fuel filtration system the fuel goes through two of those Delco style filters, ie, through one then another, before going through an inline before the injector pump.
Where did you get the pump/and what make/model is it?
Would it be worth doing it on a boat with a 40ltr tank which gets refilled aprox 3-4 times per season?
Ta, C_W
I think the point about fuel polishing is not to remove the small amounts of normal dust and stuff that accumulates in any tank, but to get out the substantial gunk that can accumulate over time in a low flow tank (as yachts are normally) where you might only use 2-3 tanks full a year, leave it sitting for weeks at a time, 6 months or more over winter, and risk fuel bugs too.
Its not as if all the fuel you use need polishing, maybe it could be better called tank cleaning?
Some tanks materials more subject to accumulating gunk than others, especially uncoated mild steel.
The pump in the image is an electric lift pump. These are a solenoid that pulses a diaphram which causes flow, they can develop enough pressure to lift fuel a few metres height, and a reasonable flow rate too.
Like this..
mm5aho wrote:
The pump in the image is an electric lift pump. These are a solenoid that pulses a diaphram which causes flow, they can develop enough pressure to lift fuel a few metres height, and a reasonable flow rate too.
Like this..
Clyde_Wanderer wrote:Not sure if I am completly grasping the concept of fuel polishing.
Does it not get polished while going through the filter while in circulation to a running engine? or is this not adequet enough?
On my fuel filtration system the fuel goes through two of those Delco style filters, ie, through one then another, before going through an inline before the injector pump.
Where did you get the pump/and what make/model is it?
Would it be worth doing it on a boat with a 40ltr tank which gets refilled aprox 3-4 times per season?
Ta, C_W
that was my thought as well, why not just use your 90 l of fuel in the tank then change the filter, top up with new fuel. Same result.
Booby Trapper wrote:why not just use your 90 l of fuel in the tank then change the filter, top up with new fuel. Same result.
A bit simplistic, though. First, we would not dream of running our 190 L tank totally dry which is what 'using it all up' would imply. Second, even running it down to, say, 10% of capacity, that 10% would still contain much of the crud that was lying at the bottom of the tank to start with. The point about polishing is to get at that crud and filter it out. Short of emptying the tank completely, taking it out and steam cleaning (see photo for some idea of what that would entail) the procedure described is a good compromise. We can be confident that we have removed much of the sediment in the tanks and that what is left is mostly small particles that will not block the pipes and will be caught by the filter. Thus the risk of engine failure due to fuel starvation (which was what prompted doing this, now) is mitigated by a significant factor.
