caustic soda clean up

All,

What is the groups view on using caustic soda for cleaning up castings etc ? I am thinking of giving it a go, any thoughts of how long you should soak for, or to use hot or cold water ?

Thanks

CHris

Reply to
Chris Bedo
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For goodness sake do not try it with an ally casting. There is a good chance you would end up with far less casting than you started with!

Tony Brooks

Reply to
Tony Brooks

I'm sure a man of Chris Bedo's cloth knows this already, but just to see what would happen, I dropped an ali casting into an electrolytic bath, only using ordinary household soda NOT caustic. I gave it ten minutes only on a

12v battery, but there were already gnaw marks on the casting, so even a short time can be "distressing".

I remember when young, a friend of mine who had had a lot of success cleaning his two stroke silencer with caustic tried it on his Vincent heads overnight. Just valve seats in the morning .........

Regards,

Kim Siddorn.

Reply to
Kim Siddorn

To answer the question :-) It works very well provided the solution is boiling. Do be careful where you tip the end result as it will contain all the nasties in the old paint! Needless to say wear appropriate clothing/gloves and I suggest a full-face mask.

ttfn Roland

Reply to
Roland Craven

Thanks all for the advice. I notice the B&Q pot says 'cold' water.. no doubt H&S requirement! I did know about the Ali, although dont have to worry too much about it, all my stuff is cast iron or steel.

One further question, once the soda has done its job, do you just wash the item and paint it ? As its quite a strong base, is simply washing with water ok ?

Thanks

Chris

Reply to
Chris Bedo

NEVER add the powder to boiling water, it will get explosive. Best to add very slowly to warm water then bring to the boil. I pressure wash afterwards. This has been more than adequate except in the case of the odd porous casting when delayed creep-out can occur. Prime when dry.

hth Roland

Reply to
Roland Craven

Some of the people re-babbitting cast iron bearings find that boiling in caustic for about half an hour is an excellent degreasing method. But as Roland says, it gets into porous castings and you need very thorough rinsing to eliminate it. There have been instances of dis-bonding of the whitemetal (babbitt) due to residues of caustic in the cast iron bodies of stern bearings of ships. I suppose that any surface treatment such as plating or painting could suffer in the same way. Phil Dando

Reply to
Phil

"Kim Siddorn" wrote (snip):-

ISTR Malc did the same trying to do Ogri a favour in cleaning up 'Armageddon'

Reply to
Nick H

Thanks All. Ill give it a go !

Regards

Chris

Reply to
Chris Bedo

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