Preparing walls for painting

[Artechim]

How do you prepare your previously painted walls for repainting?

[Visitor7]

Clean with sugar soap and water. Cut in with tape.

[~Hestia~]

Yep, wash with sugar soap. We also fill in any holes or cracks before painting too.
Good luck!

[LimeSlice]

If you are painting over oil based paint with water-based paint you will need to use an undercoat, so check with your paint shop.

[Artechim]

Thanks for the replies.
I usually wash with sugar soap first but my BIL was supposed to be doing some painting for us and looked at me like I was crazy when I insisted he wash the walls after he sanded them.

Anyhow, good to know I am right lol.

[Lulu]

BIL is a dork. How else do you get all the dust off? lol

[emc2]

It depends on how dirty the walls are.

I didn't wash the walls here much when I repainted, just sanded and dusted them down.

[Artechim]

He worked for a professional painter and so of course he knows everything. I can see how sanding and dusting would work if the walls are clean, but if there is fly poo all over the place then I don't think it is unreasonable to give them a quick wash over.

Anyhow, he decided he couldn't handle the difference of opinion, made up a barely believable excuse and left. Downside, no painting gets done. Upside, BIL isn't here lol

[emc2]

Yes my father's a painter and that is what he does, brushes it if the wall is clean, but washes it if dirty. So he's a little bit right.