If you have browsed other forums here, you would see that we have moved into our new house and got a few problems to resolve and decorating is another. The previous owners decided to paint a lot of the walls with a high shine paint (probably vinyl paint). We want to use a matt paint but concerned that it will literally slip down on the current paint. Would I get away with sanding the walls down to get a key and then sugar soap the walls and apply a 50/50 water/paint base coat before using the new matt paint? Want to get feedback from the forum as there are quite a few walls like this and want to get it right. The walls by the way are solid block walls and not studded plasterboard walls if that makes any difference. Thanks in advance guys.
Just give it a good sand to take the sheen off. You can use sugar soap or just a bit of washing liquid, sugar soap needs a fair bit of rinsing sometimes. No need to thin the paint unless it's a bit thick that's for misting on new plaster and 50/50 is too much anyway. You can use a cheap matt paint first if it's a big colour change but if not just crack on with a couple of coats. By solid block walls do you mean solid walls and plastered over or just block walls painted.
Thanks for that info Proby. Sounds like it might not be as daunting as 1st thought. Never thought of using washing up liquid on walls.. Just envisaging a lot of fairy bubbles everywhere he he. Sorry, yes, solid walls plastered over. Quite a bit of filling required as it looks like they have tried to fit shelving all over the walls in previous years.
As Prob says, you should be fine. Use of abrasive paper is the, er, key; enough to take the sheen off, flattening it nicely, tho' not 'tear' or score through the surface excessively. What grit should DJU use? 180? On a good sanding block with a felt backing or similar. Then just a wee drop of w-u liquid in your warm water - unless the walls were noticeably dirty (eg with cooking grease or nicotine). I find using old tea-towels (or other cut-down towels) good for this cleaning as it's quite 'rough' and feels as tho' it's giving the wall a good stiff clean; the likes of sponges seem to 'slip' over the surface in comparison. Also towels are easy to rinse and wring. Old T shirts are also good. If there are repair areas to fill, don't be too shocked if these bits are found to have 'raised' above the rest of the wall surface once you apply the new paint - they can absorb some of the water in the paint and swell, which the already-painted parts of the walls won't. Very annoying. Just flatten these parts afterwards and repaint. If you are going to use cheaper matt paint as your first coat 'primer', then make sure you target all these repaired areas individually and get them absolutely flat after priming. Sometimes it takes a couple of paint - sand - paint - sand - paint goes before the surface remains fully flat. And, as Prob also says, no need to thin - certainly not on the main, already-painted areas.
Didn't want to say fairy thought the mods might edit it Should have said still needs a rinse but not so much. I am assuming the wall s are not really scummy and just need to get rid of dust and general marks.
The walls are just a bit grimey from being teenagers rooms. I will probably use 180 or 120 grit paper. Was thinking of using an orbital sander, but might opt for a sanding pole to go over the walls. For filling etc, I plan to use some Gyproc easi fill which has been thinned slightly and skim over very thinly over the worst areas and use a 12" blade to smooth it over. Not a fan of all the tubs of filler
Yep, orbital is usually overkill. We are just talking about keying the surface - the minimum required to 'matt' it down.
Mirka sandpaper from toolstation is pretty good stuff. I have used a palm sander on silk paint but that's cos I'm not to gain with a pole sander, as DA says you just want to take the sheen off.
Simple really. key the sheen, wash down and then coat the wall up. Then make good any repairs with filler. Touch-in the filler when dry and sanded. Apply two coats of matt - Job Done. Good luck.
Ah, a damp wipe is different than a wash. If you're gonna wash the grease off, it needs to be done before sanding. Otherwise you'll sand it in the the sanded wall. Mr. HandyAndy - Really
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