It’s unusual for me not to do one quick sand over on a piece before starting a paint job. It’s just been my experience that without sanding, you run the real risk of your colored paint job peeling or scraping off because it did not adhere properly. I’d rather be safe, then sorry.
Definitely sand a piece if: has a glossy surface, seems slick on the surface, has roughness or unevenness, has defects that are bumps, if you plan on staining – not painting, is stained, or if you want a very smooth looking final product.
Skip to a priming coat if: the piece is laminate, Formica, or veneer. Plan on at least two priming coats and definitely look for an oil-based primer either in a spray (if the item is heavily carved or ornate) or liquid to be applied with a brush. Any oil based primer should be applied in a very well ventilated room.
Back in the heyday of lovely stained furniture, a woodworker would “go through the grits” – which means they started with a rougher sandpaper (such as a 40-60) and then to a medium (80-120), to fine (150-180), and lastly a super fine (220-600). The point of this was to remove any marks made in the wood and to highlight it’s grain to perfection. With painted pieces all the tedious grit work in a painted piece will not be needed.
An example, would be on an oak project. I would start with 80, then 120, both with my electric palm sander. At this point I most likely put on a priming coat and/or the first two layers of paint. Then I sand with a handblock at about 220. Before the last coat of topcoat I might work the surface again with steel wool (depending on how fine I want the surface to be).
Orbital Sander – is an electric sander that moves in random circles. Sandpaper sheets are applied to the face and removed when used up. If you plan on doing more then a couple of projects, or plan on painting furniture for re-sale, I would highly recommend buying one.
Use on projects that have large flat areas to work such as desk tops, bureau sides and tops, buffet sides and tops, hutches sides and shelves etc… A great piece of equipment for the first sanding and stripping.
Palm or Pad Sander – a smaller sander that can also be orbital. My Black and Decker Mouse is a one-hand sander which I use on a lot of my projects. It has a pointed tip that makes it easier to get in or rounded corners of desktops. If you are a more of an occassional DIY person, this smaller machine may fit your needs better.
Unless you are really good with your electric sander I would skip using it as a distresser – the risk is that you will take off too much. All it takes is one careless moment and that sander has ripped through a finish you worked hard to achieve.
Hand Sanding Sponges or Blocks – useful for areas where your electric sander can’t reach. I also like to use hand sanding sponges for the final sanding before the last topcoat and to do distressing techniques. Angled sanding blocks (like the one in photo below in green) are great for getting into grooves.
Steel Wool – very helpful if you want a glowing final finish, especially desirable for tabletops. Generally, if I use it (I don’t always) I do it before the last topcoat is applied. If your piece has collected some hair and dust which you want removed without damaging the paint coat, use steel wool.
Wood Rasps – these are helpful for taking off a lot of wood surface to make something level such as a room’s door that is sticking in it’s frame or a tabletop surface that needs to be leveled. More for the person who is taking their projects from casual to the next level.
Chemical Strippers – JMO I find are more trouble then they are worth. However, for removing stain or getting into highly carved areas, chemical strippers work better then sanding. In terms of brands, I’m using NEXT at this time but feel free to experiment.
After the stripper, you may need to use paint thinner to remove the gunk buildup that a stripper leaves behind. I also find wire bristled tools helpful in scrubbing out residue.
Wire Bristled Tools – use wire, not plastic. Helpful in removing gunk and layers in your carved areas.
Tacky Clothes – if you are sanding, then you need to remove all the dust. While you might want to skip this step remember that any dust left behind will get into the next layer of paint or topcoat, dulling your final product.
When sanding, wear protective eyewear (who wants a splinter in their eyeball!) and a paper mask to prevent breathing in the dust.
People are often confused about when to sand and when not too. So here are some more examples of how the procedure would work for a typical piece (remember, all projects are unique in what condition the original wood was):
Example One: vanity table (oak with pine top) was originally stained. This piece was stripped with the electric palm sander on the tabletop and chemical stripper on the legs. It was primed and painted once before being sanded again: the top with 180 electric sander, and the legs with a sanding sponge. After a final coat of paint it was given a very light, overall sanding with 220 sanding sponge before glaze was applied. Lastly, two coats of wipe on poly.
Example Two: Secretary desk (pine) was originally painted with a light color wash. There was no topcoat. I first spray primed the pine knots. Then I primed in gray and painted one coat of black. Did a first sanding with a hand sanding sponge of 220 because the pine was very thin. Two more coats of black, thinly applied with a 4″ foam roller. Steel wool was used before the final coat of wipe on poly on the sides of the piece where decorative stencil was located.
Example Three: Oak cabinet was originally stained with a varnish top coat. A light sanding resulted in this project becoming stalled – the first layer of paint was easily peeled off. I went back and did a more aggressive sanding, removing all shiny surface. In this case, if I was re-doing it, I would have put on an oil primer before the paint.
After two layers of paint, it was lightly sanded with a 220 sponge block. It was then glazed. After glazing, two coats of wipe on poly. If this had been a bathroom with a shower/bath, I would have put on a different type of paint and topcoat; something more heavy duty such as oil.