Rust spots on new plaster skim before painting

[AnimalGlu]

Hi all,

Just doing to prep work before I starting a mist coat on a newly skimmed wall and I have found a few rust spots (about 2mm in diameter).

It looks like there has been a few hidden nails in the plasterboarded wall.

After reading several posts about how to paint new plaster I was going to do the following:-
Dulux Supermatt (50% water)
Light sand
Dulux Supermatt (85% water)
Light sand
Crown Neutrals Matt Emulsion
Crown Neutrals Matt Emulsion

Do I really need to sand I assume that this is to remove any paint marks rather than touch the skim?

How do I modify the above steps to cope with the rust spots?

Also I have a tin of Dulux Pure Brilliant White Matt that I intend to use as a final coat on the ceiling, could I also use this instead of the Supermatt?

I also have a related question regarding another wall, I'll post seperately.

Thanks as always.

 

[joe-90]

A dab of oil based undercoat or primer on the rust.

 

[AnimalGlu]

A dab of oil based undercoat or primer on the rust.

I assume I should do this before anythin else?
So I'll have to buy a whole tin. Bummer.

 

[AnimalGlu]

A dab of oil based undercoat or primer on the rust.

I assume I should do this before anythin else?
So I'll have to buy a whole tin. Bummer.

I found a small tin of Dulux Trade Undercoat that lucks as though it has done the job.
I dabbed a little bit directly on each rust spot, let it dry for a few minutes and returned to add a little more and do some feathering.

I guess I'll found out if everything is okay after I have completed my mist coats. I want to use Supermatt but considering I only has two small rooms to do it seems like a waste of money as I would have loads spare.

 

[nok1]

the rust spots should be fine mate.
the only problem with supermatt is its really for use on a building site or office block etc. it will mark very easy as its quite chalky. if you have any kids in the house who will touch the walls or animals that will rub up against the walls it will mark and get dirty very quickly.
personally i wouldn`t use it in my house , better off with matt or a soft sheen depending on the finish you want. at least you`ll have a chance of wiping any marks off the walls.

 

[AnimalGlu]

the rust spots should be fine mate.

I decided to use the Dulux Emulsion Matt that I have picked up to do the ceiling, however after the 2nd 'thicker' mist coat I can see different textures where the oil based undercoat has been applied. Do I need to apply more coats of the White Matt before I move on to my two finishing coats of my final colour?

Thanks