Removing heavy scale from water jackets

[petryshyn]

Hi gents
What methods have you used for removing heavy scale from water jackets and passages?

Thanks in advance!

 

[ezeke]

Re: Removing heavy scale from water jackets

If it's salt, use Salt-Away. If its calcium, muriatic acid will dissolve it but be really careful with the stuff and have a box of baking soda to neutralize the acid. Wear rubber gloves and eye protection and don't inhale the fumes.

 

[R.Johnson]

Re: Removing heavy scale from water jackets

The only thing I know that will touch that would be mild acid, but how to get it in. More important, how to get it out. You don't want to get that scale loose in the engine, then set, and dry.

 

[petryshyn]

Re: Removing heavy scale from water jackets

ezeke
would you use muriatic acid straight, or dilute it with water or toilet bowl cleaner?

thanks

 

[ezeke]

Re: Removing heavy scale from water jackets

I would never use muriatic acid unless the parts are off the engine, then apply directly to the calcium according to instructions on the container, usually diluted to around 5% solution with water.

Salt Away just mixes with water and is bio-degradable.

 

[Vic.S]

Re: Removing heavy scale from water jackets

As a chemist I would urge some caution in the use of hydrochloric acid (aka muriatic acid) For calcium carbonate scale I would prefer to use a sulphamic acid** based descaler, sulphamic acid being a weaker acid than hydrochloric acid. In the UK we have sulphamic acid based central heating boiler descalers that can be used.

Organic acids, eg citric acid, are probably too weak to be a realistic option as the reaction rate will be very slow unless used hot.

AN alternative is Rydlyme see http://www.rydlyme.com/home.html non hazardous and biodegradable they say!

If you must use hydrochloric acid I suggest a dilution of 1 part of the concentrated acid in 5 to 10 parts water, 1 in 20 for light scaling. ( the concentrated acid is only a 30 something percent solution of HCl in water)

** Sulphamic acid , I guess spelled sulfamic acid in the US, not to be confused with sulphuric (sulfuric ) acid as use in lead acid batteries.

Goggles and gloves whatever you use. Sodium bicarbonate handy to neutralise any splashes on the skin.

 

[petryshyn]

Re: Removing heavy scale from water jackets

Thanks Gents
I think I'll research rydlyme. Seems very interesting!

 

[Vic.S]

Re: Removing heavy scale from water jackets

It'll be interesting to know how well it works if you try it.

Its composition is a bit of puzzle. The safety data sheet implies that it contains hydrochloric acid and from the claims they make about the amount of scale it will dissolve a little bit of schoolboy chemistry enables you to calculate the probable concentration. However the pH figures quoted do not agree with that concentration, they are too high!

IIRC they mention organic salts somewhere so I come to the conclusion that it must contain HCl but that the pH is buffered by the addition of salts of a weak organic acid (or acids). If that is so the rate of dissolution will not be great unless used warm. I believe there are some recommendations about temperature.

IIRC there is a diagram somewhere in their literature suggesting how to descale an outboard but to anyone who knows anything about outboards the set up will be a nonsense!

Sorry to be a bit vague. It is sometime since I looked all this stuff up but now its your turn!!

 

[wingless]

Re: Removing heavy scale from water jackets

The Trac Barnacle Buster is reported to be very good for this problem.

 

[paul2112]

Re: Removing heavy scale from water jackets

Try using simple C-L-R.. It should be mild enough to not hurt really anything maby

 

[jaymasta]

Re: Removing heavy scale from water jackets

I agree CLR works on shower heads and faucets pretty well, its probobly not the smae type of build up but it might work.