Cycling Fernox Through Engine. Any Tips?

[rhumlady]

I believe Cliff also recommended removing any zinc anodes from inside the engine as they would get eaten away by this stuff. I did this a few years ago and it cleared out quite a bit of the crud in my DV20. I hung a bucket over the stern and caught the lip on the exhaust outlet which allowed the bucket to tip and catch the water.

 

[PembrokeshirePromise]

I did this a couple of times on my old engine - and saw some improvement.

As I didn't have a mate with a bucket - and was on the water on one occasion - i cut & fitted a bucket under the exhaust output and used a little bilge pump to pump the water back up to the reservoir by the engine.

Just had to disconnect the little pump from the battery every few minutes as it ran faster than required

 

[milfordman]

I have used Fernox many times to clean out central heating systems. It works a treat. As others have said it will clean out all the crud. It should not attack the steel but if there are any cracks or leaks that are being sealed by the crud. It will expose them by removing the crud.

All the best of luck with it.

 

[VicS]

Re: How about Rydlyme??

[ QUOTE ]
isn't toxic or acidic............ Like I say not toxic so can go overboard with no ill effects...

[/ QUOTE ] Both of the Fernox products mentioned, DS-3 and DS-40 are acidic. One being based on sulphamic acid the other on "food grade" organic acids. A 1% solution of DS-3 or a 2% solution of DS-40 have a pH of 2.

Sulphamic acid is irritating to eyes and skin and armful to aquatic organisms. It may cause long-term adverse effects in the aquatic environment. Some care is therefore needed when handling and it would be best if not simply disposed of overboard.

A sensible suggestion by rhumlady/Cliff to remove any anodes although the original question referred to cleaning a MD11C which does not have any.

 

[BobE]

Re: How about Rydlyme??

I found the thraeds on scale removal very informative....Bit late I know but here's my 2d worth ( Old pennies of course)

I think my Bukh 24 has a bifurcated inlet pipe at the front of the engine, one part seems to feed the cooling water through the block and the other goes up to the water manifold and 'stat.. I've been thinking of cleaning out the crud whilst afloat and propose to use a separate pump like one of those cheapo things that fit on an electric drill...
Then disconnect the feed from the manifold to the exhaust elbow and also remove the impellor from the Bukh pump...
Feed the Fernox mix in through the inlet pipe and back out through the disconnected exhaust elbow feed into a container and back thro' the pump again.....Then I have no problems with ecology or anything else until I tip the lot into my neighbours septic tank!!! /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif
Only problem is it will of course not be a hot mix... Oh BTW I'll drain the engine first so I get the stuff into the whole water system...
Comments ???
Cheers Bob E...

 

[VicS]

Re: How about Rydlyme??

[ QUOTE ]
Comments ???

[/ QUOTE ] Comments rather than firm suggestions as I am not familiar with that engine.

Rydlyme, which appears to be a hydrochloric acid based solution, can/should be used cold, whereas a sulphamic acid based material such as Fernox DS3 needs to be used hot.

If you are going to disconnect the external plumbing and circulate cold with an electric pump then remove the thermostat otherwise the solution will mostly bypass the engine, just recycling via the bypass. If possible also block the bypass so that all the solution flows through the engine.

Rydlyme is, it is claimed bio-degradable. What effects it will have on a septic tank I dont know, but why your neighbour's?

Remove any anode or at least be prepared to renew it once the acid clean is completed.

If the water pump is going to remain in the circuit you'll have to remove the impeller.

It may not be necessary to circulate continuously. Intermittently will probably be adequate.

The effectiveness will depend on the design of the cooling system. If the normal cooling relies on convection as it does in the Volvo MD 11 etc then there will be parts that are not cleaned at all.

 

[BobE]

Re: How about Rydlyme??

Thanks for that advice Vic,
Yes I'd thought about the 'stat having to come out...
I understand that the Bukh guys are concerned about the effect of the cleaning agent on the (I guess nitrile) seals at the top and bottom of the ( I suppose) wet liners...
Don't have a workshop manual on the engine so it's all a bitty vague!!
I could of course run the engine and just disconnect the feed from the Exhaust elbow diverting into a bucket... Wonder if I could use a supplimentary feed with the "drill pump" to keep the exhaust pipe cool??
Then apart from potentially wrecking the pump impeller ( New one due anyway) and the aforementioned seals I should be fine ....

Ho Hum decisions decisions!!!

I've actually got a container of Fernox 40 which I thought of trying...

I am tempted to purchase a seal and put half of it into a Fernox solution for a couple of days and then check dimensions etc. against the remaining half...
I could even stuff it into a pan on the Aga to see at what temperature heating 'uggers it???


Re septic tank..
Well I wouldn't put the residue in mine!!!
Just a li'l joke!!

Cheers Bob E...