Furniture Painting 101: The Base Coat
A few weeks ago I was catching up on blog comments (moderating comments and replying is actually one of my favorite jobs…but somehow it always gets left for later) and over and over again I was answering questions related to finishing (or re-finishing) furniture. So I asked on Facebook whether anyone would be interested in a finishing series (with a nod toward sustainable/people-friendly materials of course) and, sure enough! The answer was yes. In thinking about how best to organize a series like this, which is so dependent on the look you would want to end up with, I decided to first divide between painting and staining, and then break it down by base coat, color coat, and sealer. Welcome to the base coat post of Furniture Painting 101.
First things first: prep.
Repair drawers, feet, doors. Remove hardware. Then your piece may need to be sanded and it definitely needs to be cleaned. If there are rough spots or chewed up edges or water damage, sand them down. Then clean the piece really well. I start by vacuuming. If it’s a new build, after vacuuming I wipe it down with a damp cloth and I’m ready to go. If it’s a previously finished piece, I vacuum and then wipe the whole piece down with a diluted vinegar solution. I know some people use TSP (tri-sodium phosphate) but I generally don’t find it necessary. TSP is pretty caustic stuff so I stay away from it when I can. I follow my vinegar step with liquid deglosser (I use the Krud Kutter brand because it is biodegradable and low-VOC). It helps remove the oils and waxy buildup that you can find on old furniture. Then I move on to my base coat.
What base coat you choose for your furniture depends both on what you’re starting with (unfinished wood? previously finished furniture? and with what kind of finish?). It also depends on what kind of look you’re going for (rustic and chippy? solid and smooth?).
For a chippy or rustic finish, it may not matter at all how you approach your base coat. The less you think about your base coat, the easier it will be to distress your piece and end up with a rustic finish (i.e.: your paint may peel right off if you don’t choose the right base coat, and this could be good if it’s the look your going for). BUT, if you don’t like the color of your original piece or if it’s unfinished or if you only want moderate distressing, you’re going to need the right base coat. When it comes to base coats for distressed finishes, my best friend is dark brown tinted primer.
Dark brown tinted primer. I happen to use the (no-VOC) Sherwin-Williams Multi-Use Primer deep base tinted to Kona. It is not the best primer out there (it’s not great for challenging adhesion situations nor for stain blocking), but it works for most of my projects and gives me control over the final look. When I’m going for a chippy/distressed finish, I use dark brown tinted primer in these situations:
- Unfinished wood when I want good adhesion and I want to trick the eye into thinking that the piece is old and has an old brown finish underneath.
- A previously finished piece when I want good adhesion and don’t want to see white primer underneath as I rub through the painted finish. If the piece is going to be white in the end, then I’d use white primer since you won’t be able to tell the difference between the primer and the paint when the paint is distressed.
Dark stain and nothing else. I will use a dark stain as the base coat under paint on new wood projects if
- I’m going to take off a lot of paint and I want to be able to see the grain of the wood underneath.
- The paint coat is going to be really thin and I want to be able to see the grain of the wood underneath.
- I want to raise the grain of the wood so that when I distress the paint I can see the grain through the paint. Water-based stains (which I use almost exclusively) raise the grain of the wood a bit (depending on the wood species — some raise more than others). This is normally considered a negative when it comes to staining, but if your purpose is to see the grain through the paint when you take off some of the paint, then water-based stain makes a good base.
Shellac. Sometimes I’ll use shellac, especially if
- The wood has lots of knots and I don’t want the knots bleeding through the painted finish (sometimes it takes years, but the knots almost always come through unless you coat them with shellac or a shellac-based primer).
- I’m working on an old piece with a very heavy/waxy finish on it that I think might bleed through the paint later. Again, shellac is great when you’re trying to combat bleed-through, whether from knots or old stain/varnish/oil-based poly. How do you know if it will bleed through? I’m not sure…it’s just a gut thing that comes with painting lots of pieces and then being frustrated that there’s bleed through. So I hedge my bets and probably use shellac more than I need to.
- I’m using milk paint on a finished piece and I want to be encourage the paint to stick…but not TOO much. (Sausha has a great post here about milk paint and shellac.)
- I’m using chalk paint on an unfinished piece and I want to be able to wipe the paint completely off in some places, with no trace left behind, and have a stained wood look underneath (I’d use amber shellac in this case, see the note blow).
Shellac is available in an amber finish which can be great if you’re working with unfinished wood. It will seal the wood (and knots) and give your wood color all in one step. Shellac is stinky because it is alcohol-based, but not the same stinky odors as oil-based finishing products. I use it in areas that are well-ventilated (usually outside) because I’m really sensitive to odors. I usually apply it with disposable foam brushes (despite my abhorrence of all things disposable) because I haven’t found an easy (or green) way to clean it up. Do not try to dilute shellac with water. It will turn into a congealed mess. Also: a note to vegans…shellac is made from secretions of the Lac bug in Asia (or this is what the trusty Internets tell me). It is not a vegan product and I don’t know how sustainably produced it is. Recently, a synthetic version of shellac hit the market but I haven’t tried it yet.
Shellac is also the best odor sealer I’ve ever used. I even use it in my utility room on the plywood sub-floor whenever my cat pees on it (she’s old…sometimes she misses the box. Give her a break). Shellac is great for all odors — pet odors, cigarette smoke (like on the green piece above), mustiness…I’ve used it on floors, drawers, insides of cabinets. It’s SO useful.
For a solid finish, the color of the base coat doesn’t matter as much, except as it relates to stretching your paint color. I know that chalk paint can go on right over any finish, but having the right color primer underneath really helps cut down on how much paint you need, and primer is waaaaay cheaper than paint. Plus…adhesion. It’s just easier for the paint to stick to primer, so that’s what I use when I’m going for a solid finish.
Dark brown tinted primer. I use the same brown primer mentioned above when I’m finishing with a solid dark paint color (like navy or black or red), just to reduce the number of coats of dark paint. Paint is not cheap and this could cut your paint use in half or at least reduce it by a third (as opposed to using a white primer).
White primer. Again, I usually use the Sherwin-Williams Multi-Use Primer, but in the regular white color. I use it when I’m putting on a solid, light paint color (like robin’s egg blue or butter yellow). It helps with adhesion and also reduces the number of coats, especially if the furniture underneath was a dark color to begin with.
Shellac. I’ll use shellac under a solid finish if the wood has knots or a suspicious coat of finish that I feel uncomfortable with (see: gut). Shellac has really become my go-to in recent years, after seeing too many old projects have knots or stain bleed through. If knots are the problem, I’ll just spot treat them with shellac and then prime over the knots with whatever primer works best for the project. Shellac-based primers cost a LOT more than multi-purpose primers, so if you’re just priming with a shellac-based primer because you want to block knots, it makes more sense to spot treat with regular shellac. Again, it may take years for you to see bleed through, but in my experience it almost always happens eventually if you skip the shellac before painting.
Milk paint. Milk paint (real milk paint that you mix from a powder, not the acrylic version sold by General Finishes — which I love) can be applied straight to a piece of unfinished furniture and it won’t come off. It won’t chip or peel, possibly not ever, even if left outside. It will eventually fade outside, but it is a really strong finish. SO, if you’re inclined to do a milk paint finish, you can just go straight from unfinished to painted unless you want a primer to get closer to your final color and reduce the amount of paint you have to use.
Chalk paint. Ditto for chalk paint over unfinished wood. I don’t think that the bond between chalk paint and unfinished wood is as strong as milk paint, but it doesn’t need a primer unless you just want to use primer to reduce the amount of paint you have to use.
What to do next…
After any base coat, I’d recommend a light sanding. One swipe with 400 grit paper over the whole piece of furniture is probably all you need. You don’t want to sand through your base coat but you do want to knock down any fuzzies you might get from the wood or just smooth out the primer coat. It really does make a difference in the finished product, I swear. Feel the piece for yourself. Wipe your hand across unsanded primer and then give it a very light sanding and wipe your hand across it again. It feels silkier and that’s what you want (or at least what I want).
What to use to apply your base coat and a few tricks for application.