yes you can, prep it first light rub down and apply two coats of the flat paint.
yes, be sure to rough up surface (sand)
Can you paint over semi-gloss with flat paint?
There are flat paints that are made to go over semigloss paint. Many inexpensive flat paints will peel almost immediately when laid over semigloss. The most common solution is to roughen the surface of the semigloss (sandpaper, sandblasting, steel wool, or trisodium phosphate). The actual requirement is to remove alkyds which migrate to the surface of some semigloss and gloss paints. The alkyds make it impossible for latex or acrylic to bond to the surface underneath. You also have to remove buildup of dirt, mildew, etc. Most primers are suitable for recoating semigloss. Read the label. A layer of primer followed by your flat paint is generally the best solution if the surface is relatively clean. Benjamin Moore Fresh Start interior / exterior acrylic primer is one example of a good primer for this application.
Doesn't the amount of varnish in the paint make the difference?
Yes, enamel paint will go over flat paint.
If you mix a flat and semi-gloss 1:1 you should end up with a paint in the eggshell range. Mix the same paints 1:3 and you should end up with a satin. Experiment with small amounts to get the desired gloss.
If it is flat paint, you can apply the texture without any additional preparation. If it is a gloss or semigloss, you will need to rough up the surface with sandpaper first.
Can I paint semi gloss over flat paint? Thanks!Barbara Phillips
Yes, significantly. Try mixing different amount of each until you create the sheen you were looking for
yes
Yes you can
Latex and acrylic (both water-based paints) do come in a semi-gloss finish.
Yes.
Yes. You can paint semi-gloss latex paint over flat latex paint. It is not advised to paint over any latex with any oil-based paint. Nor is it advised to try and paint over semi-gloss paint with any other finish without first de-glossing the finish and priming.