paint my nightmare, i need help

[gman9]

I am in greece and have said I would paint my partners flat......
I have been informed by someone that I may not be able to use emulsion because the walls may have been painted with 'idrochrome' which as far as i can see or tell translates as hydro paint.....this seems to be extremely watery when applied and then goes to a sort of powdery finish when dry. Can anyone advise wether i can use emulsion or does it have to be treated.Also someone said that if i run my hand accross the wall and it doesn't leave any powdery finish on my hand it will be fine to use emulsion.All and any help gratefully recieved.

 

[joe-90]

Thin some emulsion with 25% water and give it a couple of coats. That should lock in any dusty paint.

 

[sunshinex]

I would go with maybe a non vinyl emulsion. Or chalk or clay based paints