Yes but there is no guarantee that the colour on the surface will not streak or show a different colour through. Added to this is the fact in many houses in particular there are spray polishes used. These become airborne and do make their way to pained surfaces even if you don't actually polish that surface directly. Its a safer bet with same colour paint to give it a light rub with sand paper , then wipe with a clean damp cloth and then the satin coat should adhere to a much better standard
The paint finish doesn't significantly change the surface preparation necessary. If the paint is the same type (water based going over waterbased or enamel over enamel) then the preparation is simply: * cleaning, * remove loose material, * fill any holes or hollows, * sanding and * wiping, If you are changing the type of paint (eg: painting waterbased over enamel) you may need to use an etch primer to "key" the surface and give the new paint a texture to grip onto after sanding, and otherwise prepare as above.
Clear primer.
Generally yes but thorough scuff sanding with 200-400 grit sand paper in required. A primer will be advise by most manufacturers as well. A gloss urethane will likely show any imperfections on the surface such as rough sanding scratches.
It is never a good idea to paint anything high gloss without sanding first. You don't need to sand clear though the old paint, but the new paint needs something to hold onto. If there is nothing but a smooth, shiny surface, the new paint will probably run if the surface is not horizontal, and then chip and flake very early on. Always run a piece of sandpaper or a sanding block, 150 grit is good, over the surface. Why do something twice?
Yes, as long as the surface is free of dirt, wax and grease, and the eggshell and satin are both the same type, ie latex or oil, then you should have no trouble at all painting a satin sheen paint over an eggshell. Also, if the base is water based and the topcoat is oil, that will work fine too.
The paint finish doesn't significantly change the surface preparation necessary. If the paint is the same type (water based going over waterbased or enamel over enamel) then the preparation is simply: * cleaning, * remove loose material, * fill any holes or hollows, * sanding and * wiping, If you are changing the type of paint (eg: painting waterbased over enamel) you may need to use an etch primer to "key" the surface and give the new paint a texture to grip onto after sanding, and otherwise prepare as above.
You didn't mention whether you were using latex or oil based primer and paint, but generally the point of using primer is so that you can paint over it with any form of wall paint. Just read the label on your primer can to make sure it is compatible. On the other hand, if you wanted to paint the primer over the satin gloss, you need to sand the surface lightly to remove the sheen of the paint and provide a suitable surface for the primer to adhere properly.
All you need is good preparations: sanding and degreasing.
Clear primer.
You can but you will want to give the vaneer a light sanding first.
Arson.
Generally yes but thorough scuff sanding with 200-400 grit sand paper in required. A primer will be advise by most manufacturers as well. A gloss urethane will likely show any imperfections on the surface such as rough sanding scratches.
Yes, that would work as a painting technique.
It is never a good idea to paint anything high gloss without sanding first. You don't need to sand clear though the old paint, but the new paint needs something to hold onto. If there is nothing but a smooth, shiny surface, the new paint will probably run if the surface is not horizontal, and then chip and flake very early on. Always run a piece of sandpaper or a sanding block, 150 grit is good, over the surface. Why do something twice?
Yes, Eggshell and Satin are very similar. Though i would recommend scuffing the walls with a sanding block or sandpaper to help with adhesion . Also current and new colors will make a difference, you may need to use primer if applying a lighter color over a darker one or if there are excessive stains on the walls.
If the old layer is good: just sanding and degreasing. If it's more damaged (chipping, cracking, etc), do some extra preps (use a shave-hook, and fillers to equalize the surface). But anyway, with some sanding it will hold.
Yes, as long as the surface is free of dirt, wax and grease, and the eggshell and satin are both the same type, ie latex or oil, then you should have no trouble at all painting a satin sheen paint over an eggshell. Also, if the base is water based and the topcoat is oil, that will work fine too.