anybody used brick acid?

Birdseye

Birdseye

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My raw water cooled engine and the feed pipes to the calorifier are a bit crudded up with what I believe is carbonate salts. Like the pipes on your sea toilet become.

The local V**o dealer tells me that he uses brick acid poured into the cooling system with the boat out of the water to dissolve this material and clean the cooling system. I cant remember whether the acid is nitric or hydrochloric - i believe the latter.

I'm going to have a go in due course but before I did I wonder whether anyone else has tried the same trick? What did you do about the frothing? Or the copper pipes? Did you run the engine to warm it up? Did you remove the thermostat? And did you suffer any damage?
 
I too would be wary of using a stong acid like hydrochloric. I had not thought about anodes that is a very good point but I suppose you would simply fit new ones once the job was done.

In my (professional) opinion it would be much safer to use sulphamic acid, which is sold as central heating boiler descaler eg Fernox DS-3. It would be much slower but there would be less risk of doing damage to the engine, although it would probably dissolve the anodes.

I have no idea what concentration you would use if you used hydrochoric acid, about 1 part concentrated acid to 10 parts water?. I would guess though that brick cleaner is already a slightly lower concentration than the concentrated acid you would find in a chemistry laboratory.
 
One of the bigger Volvo resellers and secondhand suppliers here told me to use brown vinegar, whereas previously I'd used dilute hydrochloric. I've yet to try it, but it sounds like a "healthier" alternative.
 
Vinegar contains acetic acid which is a very weak acid. I think you will find that it will be very slow. It might remove light scaling and enable you to keep an engine clean but doubt if it will be much use to descale a severely scaled one.
 
My engine has an internal fresh water cooling system that runs though a seawater-cooled heat exchanger.

The engine was overheating and it seemed that both systems were likely to have been a bit consipated. I used a solution of oxalic acid on both systems, and it seems have worked well.

Heat exchanger - warmed up the engine, then disconnected the seawater intake (closed cock first) from the cock and connected it to a two gallon bucket of oxalic acid solution. Ran engine until the bucket emptied, switched off engine, re-connected pipe to cock. Left for 5/10 minutes - restarted, flushed seawater through as normal.

Engine internal cooling system - basically as before, warmed engine, drained colling system, re-filled cooling system with weakish solution of oxalic acid, ran engine for 5/10 minutes after thermostat properly opened. Drained, flushed through several times. Also flushed with solution of bicarbonate of soda to neutralise any traces of oxalic acid. Flushed through again with clean water. Then added coolant.

Both measures have reduced the running temperature to an acceptable level. The cleansing of the heat exchanger had the greatest effect.

Directions and discussions about solution strength are very vague, but if you Google....

Hope this helps.
 
Oxalic acid is a stronger acid than acetic acid, but less strong than sulphamic acid. Using it warm will have helped considerably. It is not quite so readily available as central heating boiler descaler though
 
According to Schweitzer's Corrosion Tables, even diluted hydrochloric acid is a corrodant to stainless steel as well as aluminium.
 
IMHO as per personal experience, I would dilute 1 litre of brick acid in 5 liters of water, then have the engine suck it in three times, leaving the solution in the engine for 10/15 minutes. Did it in my VO 2002 and worked great.
Cheers,
Gianenrico
 
the bits that make me nervous are the coippoer bits that Volvo engines use. So I guess I will have to try the acid solution on a bit of copper in a bucket first.
 
I can predict the out come of that. You will find that cold dilute hydrochloric acid does not attack copper but it does attack other metals that you may find in the system. It will slowly dezincify brass, attack aluminium and the iron itself ,even some stainless steels.

If you do use HCl only leave in in the engine long enough to remove the scale then drain it from all points flush it out thoroughly and preferably neutralise any that remains with a solution of sodium bicarbonate. Do not leave any un-neutralised in the bilges as the hydrogen chloride gas is released as it evaporates.

Take care to protect your self from splashes and wear goggles. Neutralise the waste with washing soda and dispose of safely.
 
Hydrochloric acid is a strong acid, and will attack metals of all types. Sulphamic acid, so called vinegar ( acetic acid) and other organic acid like citric and tartaric acids are weak acids and will not attack metal to any degree, but will either dissolve salts, or chelate iron salts, which block water ways.
Suphamic and citric acids are both used to clean boilers in nuclear power stations, because they clean but do not attack metal and specifically the welds between pipes. I use citric from the wine making shop, dissolve it as little water as possible, add it the filling point with sea cock turned off, run the engine for a couple of minutes to get the solution warm, and then leave it to pickle overnight. At the end of the exercise what comes out of the back end after the sea cock is opened and the engine started, is quite surprising.
On the other hand perhaps not so. In the Solent two days ago we had a quite a bit over the side and within 10 minutes the water had dried on the port holes, leaving a salty crust.
 
[ QUOTE ]
Hydrochloric acid is a strong acid, and will attack metals of all types

[/ QUOTE ] Well cold dilute acids will attack metals more electronegative that hydrogen (with some exceptions) but generally do not attack electopositve metals. That includes copper. That even applies to the weak acids but the rate of reaction is so slow that it becomes insignificant.

Sulphamic acid is the stongest weak acid that I can think of with a dissociation constant of 0.101 giving a pH vs concentration curve shown below
figure2.gif


I would agree with your cleaning procedure using citric acid but I do not think you can compare engine cleaning with cleaning of power station boilers, be they nuclear or conventional, as that will be done under careful supervision with monitoring of acid concentrations etc. Also the acid cleaning solutions used will be inhibited to reduce the attack on the metal itself. (If you want to find dodgy welds (in temporary pipework) try hydrochloric acid containing ammonium bifluoride!)
 
Yes

Remove engine anode and replace plug.

Remove thermostat and drain engine down, replace plug.

Dilute 5% Hdrochloric Acid brick and masonary cleaner ('cos it's cheap) 1:1 to make 10%.

Fill engine gradually down thermostat hole (use good personal protection).

Allow to work, dip thermostat and cover to clean if required.

Replace thermostat, run engine to rinse thoroughly, have a look to see if you have had the required effect.

Repeat if necessary.

Works a treat, will not damage any engine metals or seals if used as shock treatment and rinsed thorougly. Don't leave in all winter however.
 
Re: Yes

[ QUOTE ]
Dilute 5% Hdrochloric Acid brick and masonary cleaner ('cos it's cheap) 1:1 to make 10%

[/ QUOTE ] Something wrong with the arithmetic there I think. Or have you just got the 5 and the 10 the wrong way round
 
[ QUOTE ]
I use citric from the wine making shop

[/ QUOTE ] it will fix your b&w photos too, if you haven't gone digital. Acetic acid has nasty fumes in any concentration, citric doesn't.
 
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