Which Stain Block?

[ReganAndCarter]

I've got some white, emulsioned plaster coving in my lounge that has a small stain about the area of a fag packet. It's a water mark from a small roof leak. Can anyone recommend which stain block I can use, so I can emulsion over it? Preferably small size can bearing in mind the small area. I tried putting a coat of white emulsion over it, and the stain came through just as bad.

Thanks for any advice.

 

[opps]

I would use a shellac based primer but only because I can paint over it after about 30 mins, but if it is only a tiny spot, you will be paying through the nose (assuming that it is only a small area).

If you are not in a rush, and have some, use an oil based undercoat. Wait 24 hours before overcoating.

If you haven't got any oil based undercoat but have some cellulose spray paint, that will suffice, just give it a light scuff (without cutting through the paint).

Be advised that the emulsion will take longer to dry because it cannot soak in to the substrate though

 

[ReganAndCarter]

Thanks, Opps. Yes, only very small area. Will take a look in garage, think I have some oil based undercoat. Save me buying Zinsser or whatever as it's quite pricey. Few years ago a decorator had to use it on every wall in a house were were selling for my cousin who was a heavy smoker. The stuff really smells, felt bad for the decorator.

 

[opps]

Thanks, Opps. Yes, only very small area. Will take a look in garage, think I have some oil based undercoat. Save me buying Zinsser or whatever as it's quite pricey. Few years ago a decorator had to use it on every wall in a house were were selling for my cousin who was a heavy smoker. The stuff really smells, felt bad for the decorator.

Zinsser BIN smells but it is just the smell of alcohol.

The first time I used it to paint a whole room, I used a charcoal filter mask. Now that I know that it is only alcohol, I don't bother wearing a mask.

BTW, if you don't have any oil based undercoat, you can buy a small bottle of knotting solution. It is the same thing as BIN but without any pigment.