descaling heat exchage stack

[duke]

I want to desc /forums/images/graemlins/smirk.gifale the brass / copper stack in my (engine) water heat exchanger.
The engine book says to use "washing soda".

I already have two descalers in my shed.
One says it contains "sodium hydroxide 99/100% concentrated pearl".
The other say it contains "sodiumcarbonate decahydrate more than 30%".

Can anyone advise if either of these is "washing soda"?



Thanks,

Duke.

 

[savageseadog]

Use a plumbing descaler containing sulphamic acid (not sulphuric!) I can't think why they'd recommend washing soda

 

[John100156]

Try using Fernox DS-3, it contains Sulphamic acid with inhibitors, indicators and non-foaming surfactants.

This is used commercially for removing limescale from any type of water heater to restore its efficiency. It is safe to use with steel, stainless steel, cast iron, copper, brass, PVC, ABS rubber polythene and most plastic pipework systems.

First dissolve in hot water, at the maximum concentration of 1 kg per 10 litres of water and a minimum concentration of 250 g per 10 litres of water (10% - 2.5%).

Hot water will accelerate de-scaling but do not exceed 80°C. The de-scaling process will release carbon dioxide gas (CO2), which can cause foaming. Hence, space should be allowed for this before commencing work. A colour change from yellow, through green, to blue indicates the de-scaling power is exhausted. However, the major part of the solution's effort is expended when green is reached and if cold the final change to blue can take a long time. When de-scaling is complete, drain and rinse several times until no traces or odours remain. It can be neutralised with Fernox Superconcentrate System Neutraliser.

Most of the above copied from the Fernox website: Fernox DS-3

/forums/images/graemlins/cool.gif

 

[alan_d]

Yes, the second one (sodium carbonate) is washing soda.

I'm not saying it is the best stuff to use, though.

 

[VicS]

If the engine book says use washing soda try it but being itself sodium cabonate, as already said, it wont have any effect on a calcium carbonate limescale.
(nor will sodium hydroxide/caustic soda)

I'd go with the suggestion to use Fernox DS-3.

 

[lw395]

Sodium carbonate is washing soda
http://www.elc.org.uk/pages/envirocleaninghtm.htm
either acids or alkalis can be used, both can be detrimental to metal if overdone.
Brick cleaner is a cheap handy source of acid sometimes phosphoric, sometimes sulphuric, check the safety info!
Maybe best to use something milder unless desparate?
A central heating descaler might be appropriate give the mix of metals? But might require use at temperature.
A mechanical approach has advantages where possible!

 

[VicS]

Alkalis won't remove limescale.
Brick cleaner is commonly hydrochloric acid but there is a wide variation in concentration.
Central heating descalers are generally used hot or at least warm. Some are based on organic acids, which will react only slowly when cold (Eg Fernox DS-40) DS-3 is based on sulphamic acid as alredy stated. That is a stronger acid, although not as strong as hydrochloric, sulphuric etc.

One of the advantages of using a central heating descaler is that it is inhibited to minimise attack of metal components. Brick cleaners are not!

 

[duke]

Tried Washing Soda but not satisfied with results.
Fernox did the job!

Thanks to all for replies and suggestions/advice.


Duke. /forums/images/graemlins/smirk.gif

 

[vyv_cox]

Just for general interest, washing soda is very good for cleaning up aluminium. More years ago than I care to remember, motor bike magazines regularly featured articles entitled 'Go boil your head'. I recall boiling my cylinder head in washing soda solution and it coming out like new.