Cycling Fernox Through Engine. Any Tips?

CaptainBob

CaptainBob

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I'm going to cycle 2kg of Fernox DS3 through the cooling channels of my Volvo MD11C.

My current plan is to have a large container in the cabin with the engine intake in it, and a friend at the back of the boat with two buckets... as each bucket is filled, I'll carry it to the cabin and pour it in to the large container, then take then empty bucket back to my friend, and grab the next one.

Any better suggestions? I think I'm going to have a bit of loss of cooling water each time we swap buckets, and I'm worried that this way I'll end up with all the crud from inside the engine potentially getting sucked back into the cooling circuit, potentially blocking it up somewhere.

Cheers
 
A more common way to do it is to tie a 5 gallon plastic bottle over the transom, after cutting the top out, to catch water coming out of the exhaust. You can push a short length of hose into the exhaust, if necessary, leading it into the container. Take the suction pipe from the engine directly into this container. Don't push it right to the bottom or, as you say, you will pick up solids that have been ejected, although it's a good idea to include your strainer in the circuit. I have found that it sometimes takes a bit of ingenuity to fill the suction hose with water and get it started, but once away you can leave the engine running almost indefinitely.

To take full advantage of the treatment you need to run youe engine for some time so that the thermostat opens fully. Otherwise, you will treat the bypass but not the engine itself.
 
Is it the view that this is a good think to do with an older raw water cooled engine?

Should I consider doing it before I go back in the water?

Engine is Volvo MD7A
 
Cheers Vyv, genius. I'll give that a go.

[ QUOTE ]
Is it the view that this is a good think to do with an older raw water cooled engine?

Should I consider doing it before I go back in the water?

Engine is Volvo MD7A

[/ QUOTE ]

Take the thermostat out and have a look inside. Mine was pretty furred up, and one of the two cylinders runs somewhat warmer than the other, so I'm doing this in the hope that I can clean up the passages a bit and solve both problems. Fingers crossed!
 
I'm wondering about this treatment reading this post.

My volvo 7b might benefit also. It would be good to hear from users about the effectiveness and also if there might be any side effects of using Fernox in particular
 
I haven't tried this yet but it's a tip from my son. He is in the air conditioning/refrigeration business on big and super-yachts. He circulates swimming pool cleaner around all seawater systems and swears that it is the only stuff that clears everything out. I have no idea how it would take to being heated in the engine, but it might be worth trying as a pre-treatment?
 
As a plumbing and heating engineer I would recommend only using the descaler from Fernox if you are happy that there are no potential cracks and leak points on your system - remember this is a scourer and will clean the crud inside the cooling system down to bare metal. In a heating system this sort of scouring is followed by adding an inhibitor to the water to protect the inside of the pipes from corrosion - obviously not possible if done on a raw water system but if boat is out of the water this would be a good idea so as to protect until future use.

Despite the manufacturers claims be very wary of using where there is Aluminium in the system.

Remember to neutralise and flush out with clean water thoroughly when completed - if any of the descaler remains in the system it can cause problems!
Probably best to remove your thermostat before starting the job if possible to get the best flow rate throughout the engine.

PS - Fernox is good but other descalers are available from your local plumbing merchant! - All descalers work best when warm.
 
I can't improve on the techniques recommended above, but
I don't understand why you're using Fernox and not antifreeze though? Is there no risk of freezing? Or do you fully drain it all down afterwards?
 
I've used DS-40 plenty of times for descaling boilers and it's good stuff.

Just be wary it will find any weakness in the plumbing system that is covered over in crud. So don't leave it chugging round your engine and walk away to the pub.
 
Re the comment about removing the thermostat. Dunno about your cooling circuit, but when my thermostat opens, it actively blocks the bypass circuit, forcing coolant to flow through the engine channels. If I removed the thermostat there'd actually be less flow through the engine channels, not more.
 
Just my 2ds worth. I mentioned my plan to use Fernox descaler on my Bukh DV 20 (direct raw water cooled) to Al Pearson @ Bukh UK and he advised against putting it through a running engine. I did take the exhaust manifold off and soaked that in Fernox & this did work very well indeed, tho flushing & second treatment was worthwhile. I used the material at the strongest concentration recommended on the pack.
 
[ QUOTE ]
But can anyone clarify what type of Ferrnox to use

[/ QUOTE ] I suggest that DS-3 boiler descaler is the most appropriate to use. It is based on sulphamic acid which although, in chemistry terms, is classed as a weak acid it is just about the strongest of the weak acids and will work reasonably quickly. DS3 contains inhibitors to minimise the attack on the metal itself.
(In chemistry strong and weak when used to describe acids, or alkalis, have a specific meaning and are not synonymous with concentration)

The alternative is the system descaler DS-40. That is based on organic acids which are not as strong as sulphamic acid. The cleaning time required is much longer although it could probably be shortened by using a higher concentration than specified.

The Fernox website is www.fernox.com although www.fernox.co.uk will take you to the fernox products on the Plumbworld website. There is more info on the UK Plumbing website at http://www.uk-plumbing.com/water-treatment-fernox-water-treatment-c-436_438.html .

Some people use hydrochloric acid (HCl) which can be bought as brick cleaner. HCl is a strong acid and it will work very quickly and at ambient or only a slightly raised temperature. It is not inhibited in the way that the central heating cleaners are and I would be very cautious about its use.

DS40 is I believe supplied with neutralising agent and DS3 can be neutralised with "Fernox Superconcentrate System Neutraliser" Personally I'd probably use washing soda and check that it is neutralised with pH paper but I realise not everyone as pH papers to hand.

Caution should be exercised if there are any aluminium components in the system I notice that the information on these cleaners does say they are not suitable for use on thin gauge or badly corroded aluminium.

Please all report back telling us what you used, briefly what you did and how effective you think it may have been.
 
I've used the DS3 and it doesn't seem to touch the metals. If something were to go through it would have gone anyway.
 
I can only add to Vic's brilliant exposé that aggressive and fast descalers have a tendency to break up the scale in largish chunks, in stead of being "eaten away". Blocking of the passageways is the result.
 
Some good advice on this thread.

Although Al Pearson and Co at Bukh do not recommend using descallers it is more a case of covering themselves in the event somethng goes wrong.

A search on fernox on these fora will turn up several threads on the subject.

Personally I followed the method described by cliff (see thread above) and had no problem using fernox DS3. Reading that ond other related threads it appears many people have used fernox with great success. (someone will come along now and say they damaged their engine!)

Tom
 
How about Rydlyme??

I have used this a number of times, seems to work well, isn't toxic or acidic.

Gently dissolves, not break into chunks.

It does take a while and works well if continuously circulated for a number of hours. I use a spare Jabsco pump and just leave it running a few hours.

No relation to Rico...just satisfied. Also cleaned my props with it, and down the toilet and everywhere else!!!! Like I say not toxic so can go overboard with no ill effects...
 
All good advice, I've tried it, and it did help a little. But for not a lot of effort and little cost it's worth taking the manifold off and cleaning the crud out of the channels. The crud is quite hard and takes some shifting. The hole that takes water from the manifold, into the heads is not very large and is prone to blocking.
 
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