De-scaler

[asj1]

Next week-end I expect to start work on removing the cylinder head on my Bukh DV20. I am told I can then use de-scaler to help get rid of the scale which will have built up in the head and manifold (but not to use it on the block). Any suggestions as to which de-scaler would be effective and where to get it from.

Regards

<hr width=100% size=1>Andrew

 

[Capt_Scarlet]

I bought some stuff from a car accessory shop, and it was rubbish. Then used some Kilrock kettle descaler - fizzed away for ages, and did the job.

I have heard of using brick and tile cleaner, but haven't tried it.

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[richardabeattie]

How about feeding the descaler into the system via the water pump (using an old impeller perhaps) and letting it do its stuff without taking off the head?

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[Stemar]

Brick cleaner is a fairly dilute hydrochloric acid. It won't hurt immediately if you spill it on your hands, but as it dries off it becomes concentrated - ouch! Wear gloves and goggles, and don't spill it on SWMBO's favourite carpet.

Kettle descaler is ususally citric acid. It'll sting like hell if you do get some in your eyes, but is unlikely to do any real damage. Probably more expensive and slower, but safer.


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[jimiboy]

We always use bog-standard vinegar in the kettle....brings it up a treat overnight.

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[pappaecho]

The best product for the job is sulphamic acid which is used by professional boiling cleaning and descaling operations. It is a weak acid, and definitely not sulphuric, which is a strong acid. try Ellis and Everard for supplies.
Failing that Citric acid from chemist or homebrew suppliers removes all sorts of rust, not only from Bukh cylinder heads but also rust stains on sails - without any detrimental effect... you can also flavour your G&T to get a lemon flavour!

<hr width=100% size=1>Def: Yachting - a way of spending the kids inheritance

 

[steve28]

Try this product before you do the stripdown, i found it very effective and now have an engine thats as good as new !
www.rydlymemarine.com


steve

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[snowleopard]

spent a few days back in the 70s helping an engineer strip and overhaul the engines of an 80 ft riverboat (2 litres per cylinder, individual cast heads, each 3 cyl 36hp engine weighed over a ton!)

because the boat used to creep up the Dart on the first of the flood its waterways were full of all sorts of crud. he put each head on a gas ring to cook for half an hour then poked the tang of a file into the waterways and cracked out the deposits. the engines ran reliably every day for a good 20 years.

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[cliff]

I just cleaned my DV24 using "fernox" central heating descaler - worked a treat.

I put a bucket in the cockpit and ran a hose from it to the cooling water (raw) on the engine, filled the bucket with fresh water and ran engine, topping up the bucket with more fresh water as needed. Once the engine had run at normal temp for about 10 minutes I placed another bucket below the exhaust to catch the discharge and used a small inline pump to pump this discharged water back to the bucket in the cockpit. I then added the "fernox" to the bucket in the cockpit and continued to run the engine under load (well tied to the pontoon) until it was "hot", topping up with fresh as needed. Within a few minutes the water went black as the crud was dissolved and washed out. I continued to circulate the coolant for about one hour adding another bottle of fernox to compensate for losses at the exhaust.
Result was one very clean engine which heats the calorifiermuch better than before and no longer overheats on full power.

It helps to remove the stat after the fresh water flush so there is a good flow through the block / head. As one is recirculating the coolant the engine will warm up even without the stat.

"Fernox" is available from plumbers merchants or B&Q for 2~3 times the cost from a plumbers merchant

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[asj1]

Cliff,
Interesting that you ran it through your engine. I was told by Bukh not to run descaler through the block as some "o- rings" or seals at the bottom of the cylinder wet liners may be damaged presumably you didn't find this? I was intending to merely place the de-scaler in the cylinder head and manifold and not run it through -- from what you have said it doesn't appear likely that Fernox would work in this way.

<hr width=100% size=1>Andrew

 

[steve28]

I was strongly advised agasint using this type of product. It was suggested by many that the effect on the engine is severe and causes damage to rubber, paper and alloys.
The company i mentioned in my other post has a uk distributor who will send a free sample pack out. Is worth it even to try it on things they say it dissolves. I tried bits of rust , mud, barnicles, and it all just fizzed and dissapeared !


steve


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[cliff]

I did not find any damage or leakage after the descaling although I did flush the engine out well with fresh water after completing the descaling..

Looking at the problem from another direction, if "Fernox", used almost in accordance with instructions as regards to concentration and temperature, damaged seals, "O" rings etc it could not be used on domestic central heating boilers / systems as the "O" ring seals in the motorised valves would be affected as, more than likely, would the pump seals.

As with any of these things if left in the system for prolonged periods then some damage may occur.

Although I used "Fernox" to great advantage, and will use again if needed, as with all such non-proprietary treatments - user beware!

In the present "compensation" society companies tend to err on the side of caution - just in case there is a problem and a claim for compensation hence comments such as "we do not recommend using product ******* as it may damage component ^^^^^^^" They are then covered if you find the problem.

Always remember descaling an engine can cause leaks which were originally sealed by the scale. The seals at the bottom of the liner could be knackered but the scale is providing a seal - remove the scale and you have a leak - now where did I put the bottle of "RADWELD"...........

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[jfkal]

The product you recommend seem not to be suitable for raw water cooled engines ?! /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif