# Texturing over painted walls



## l1r (Apr 2, 2008)

Which primer should I use? 
I've got walls with knockdown texture that's painted with, probably, semi-gloss paint. I want to skim it and make walls nice and flat (and paint after that). 
How should I prime existing paint to make sure whatever I skim with sticks?
Also - don't know if this belongs here or not, but - what would I use to skimcoat? Joint compound? Stuff that's sold in bags and you have to add water, or stuff that comes in boxes and is already premixed? (later preferred ) 
Thanks.
Tim.


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## Nestor_Kelebay (Jun 17, 2008)

Well, Zinsser's boasts that their Bullseye 123 latex primer will stick to smooth surfaces like high gloss oil based polyurethane and even glazed ceramic wall tiles. So, if it'll stick to those surfaces, it should have no problem sticking to your textured walls.

Zinsser also makes a shellac based primer called "BIN". Shellac will stick to anything short of a raw egg yolk. That would be another option. Shellac based primers are thinned with alcohol rather than water or mineral spirits, so that might present a bit of a problem.

Yes, a drywall joint compound is what you'd normally use to skim coat over the texture on a wall. Be aware that there are different kinds of drywall joint compounds, and the difference is in the amount of glue they add to them. The more glue, the better the compound sticks, but the harder it is to sand smooth.

You can overcome this problem by painting over your primer with dilute white wood glue (diluted with enough water to make it into a paintable consistancy), and then applying a joint compound without very much glue in it. That way, the glue layer provides excellent adhesion, but the lack of glue in the compound itself provides easy sanding.

Regular, or "taping" drywall joint compounds stick the best, but are the hardest to sand smooth.
Finish, or "topping" drywall joint compounds have the least glue in them and are the easiest to sand smooth.
All Purpose drywall joint compounds are about half way between, and are popular with plastering contractors because it allows them to do everything with only one product.

If it wuz me, I would use a powder and mix it myself. Just go to any small appliance repair shop and ask them for a kitchen mixer blade. Mount that in an electric drill, and mix your joint compound inside a cardboard box so that any compound that comes flying off your mixer stays inside the box.

If you do use a premix, don't be scared to thin it. I've been plastering for over 20 years, and the very first time I used a premix, I thought it was way too thick. They mix it thick because they know the customer doesn't like paying for water, and can thin it himself.

And, ALWAYS, ALWAYS, ALWAYS, when applying plaster or sanding it down, work with a bright light near the surface you're working on. The critical lighting angle will exagerate the roughness of your surface, letting you know where to add plaster and where to sand it down to get a smoother surface. Once your surface looks acceptable to you under such critical lighting, it'll look perfect under normal lighting.

So, if it wuz me, I'd prime your walls with either Bullseye 123 or BIN, and allow to dry. Then I'd use a thick pile roller to paint over the dry primer with diluted white wood glue and allow to dry. (The wet joint compound will re-activate the dried wood glue, bonding the joint compound to the primer.) Then apply probably an All Purpose (or Topping) joint compound over that using as wide a trowel as you can find. Allow to dry and knock off any ridges or blobs when dry using a paint scraper, and apply another coat, trying to go perpendicular to any ridges in the first coat. Do this with a bright light close to the wall making things look worse than they are. Once your wall starts to look smooth, sand your trowel ridges down rather than scraping them off. And, when your wall starts to look smooth, you DON'T have to skim coat the whole wall. Just apply joint compound where needed to get it smooth. And, the wall doesn't need to be FLAT. If it's smooth, it will also look flat (for lack of evidence to the contrary).

Then, just prime and paint.


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## l1r (Apr 2, 2008)

Thanks, that was very helpful. I'll try this sometime this week. I also wanted to make some swirls in the texture (random 180 degree about 18" radius swirls of texture - I've seen it done before), would a second coat be the right time to make those?


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## Nestor_Kelebay (Jun 17, 2008)

l1r:

I really don't know anything about texturing walls. Your best bet might be to phone up some plaster contractors who have to match textures after making repairs to plaster walls. They could advise you better.


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