Sludge

[Tony Foster]

Hi, we have drained the skin tank of our recently purchased 40 year narrowboat in order to change the coolant and have found there is an approx 3cm layer of black sludge at the bottom of the tank which a hose pipe does not shift. Does anyone have any suggestion for the best way of cleaning this out? Cheers

[WotEver]

I'd guess that sludge remover would do it if left to soak for a while. Something like this: https://www.mrcentralheating.co.uk/sentinel-x400-sludge-remover-1-litre?utm_source=google_shopping&gclid=Cj0KEQjw6-PJBRCO_br1qoOB4LABEiQAEkqcVRamNiCry_BF0cVsQbC6pR-tA8wSp_V-qKK075VWJJcaAvOz8P8HAQ#.WTmPHoXTWEc

I guess you know that it's caused by a lack of antifreeze?

[Tony Foster]

Thanks, no didn't know what caused it but don't think coolant changed in a long time. Would you pour a litre of the cleaner on top of the sludge, let it soak a while then flush it all out? 

[WotEver]

16 minutes ago, Tony Foster said:

Would you pour a litre of the cleaner on top of the sludge, let it soak a while then flush it all out? 

I would, plus some water, yes, and 'a while' might be several hours - you'd need to read the instructions.

If it's more convenient for you, Screwfix sell sludge remover too (as do all plumbers merchants). 

[WotEver]

It might well be best to refill the cooling system with the sludge remover added and leave it in the system for a few days. Then flush through and add a proper antifreeze mixture. See what the instructions say. 

[Tony Foster]

Ok, will get hold of some and follow the instructions. Thanks for your help.

[Jen-in-Wellies]

On an old car the advice would be to turn the radiator upside down and reverse flush it with a hose to remove the sludge. Not so easy on a narrowboat with a built in skin tank

Jen

[dmr]

You must have some access to see that the sludge is there, so.....can you make yourself a water jet sludge stirrer? Get a length of 8mm copper tube, flatten one end to leave a narrow slot, and put a suitable adaptor on the the other end to connect to a hose. Then just stir up the sludge till it drains out.

The copper will bend easily to get to the deeper parts of the skin tank. I made something like this for doing the pump out flushing.

..............Dave

[Tony Foster]

Like the idea of creating a stronger jet with copper pipe as there is a filler cap on the skin tank. The stuff just didn't shift with the power of a hose pipe. Flipping the boat upside down might be a bit extreme Jen, although it would make it easy to black it.

[MtB]

2 hours ago, Tony Foster said:

Like the idea of creating a stronger jet with copper pipe as there is a filler cap on the skin tank. The stuff just didn't shift with the power of a hose pipe. Flipping the boat upside down might be a bit extreme Jen, although it would make it easy to black it.

If it's that difficult to shift why not just leave bit there?

Is it doing any harm??

[tomsk]

15 minutes ago, Mike the Boilerman said:

If it's that difficult to shift why not just leave bit there?

Is it doing any harm??

Good point.

Unless you are actually overheating or it looks like the circuit is in danger of being obstructed I would leave well alone and simply monitor.

There's no harm in flushing it daily if you can afford the time and coolant costs but I would suggest there would be little gain either.

I certainly wouldn't advocate any attempt to break-up or disturb any calcification.

 

 

 

[carlt]

You could try feeding a pressure washer drain jetter through the tank.

I acquired one very cheaply with little confidence in its effectiveness and was amazed at just how powerful it was in clearing sludge that my traditional rods failed to shift.

[Tony Foster]

Thanks all. I guess it's been there a long time so prob not doing any harm although outflow from skin tank is right near the bottom. I haven't any access to mains electricity at present or a good enough inverter for a pressure wash. Might save that for next time coolant changed and clear out what I can this time without trying to get it all out.