Sanding wooden furniture, an essential step in a renovation. Sanding is a simple job, but it quickly turns tedious if you don’t have the right tools and if you don’t respect a few basic principles. I have told you about it several times here, one of my activities was to renovate old furniture for several years. You often ask me for advice on sanding furniture on Instagram. Therefore, I will detail to you step by step how I proceed; I hope that my advice will be useful to you and help you get started to revive a wooden piece of furniture!
1 / How to sand wooden furniture? Is furniture waxed or varnished?
It is the resposbility of the furniture manufactures, Before sanding wooden furniture, it is necessary to determine what finish has been applied. Indeed, not all are filed.
The two main finishes are waxed furniture and varnished furniture. When observation is not enough to decide, there are several ways to know what finish has been applied. A number of the proposed methods are chemical-based, which I try to avoid.
I offer you a very simple and non-polluting trick. Pass a 120 grit sandpaper over a small area of the cabinet that has already been cleaned and observe the result:
– if the paper is clogged with a kind of paste as in the photo below, it has probably been waxed
– if the paper remains “Clean” and the sanded surface rather generates dust that does not stick, it has probably been varnished.
Waxed woods do not sand; you would only get the sandpaper dirty and “smear” the wax by heating it. You will therefore have to unbleach the furniture beforehand. The varnish is sanded very well!
2 / How to sand wooden furniture? Identify the different woods and the manufacture of the table.
To know how to sand wooden furniture suitably, you have to be interested in how it is designed, particularly the type (s) of wood used. There are several techniques to obtain this information, and I share a very simple and often the most effective one, which is to turn the furniture over. This allows you to see the inside, which is very instructive. Once you know what support you will have to send, you can do the right things and use the right tools!
On this piece of furniture, we can see that several types of materials were used in the photos below:
- solid wood for the uprights (picture on the left): observing the edges, we see a logical continuity between the wood fibers on the different sides. We can see that it is, therefore, “one-piece.” Here, the wood used is oak.
- Plywood for the furniture panels (photo in the center): the top and sides. Plywood is often used for this type of furniture because it is less expensive and, above all, lighter. This makes it possible to have a thin and resistant board thickness at the same time. It is made up of several thin plates or sheets of wood glued together perpendicularly. We reverse the direction of the wood grain by superimposing the layers for more resistance.
- Veneer for the sides and the exterior top (photo on the right): it is a very thin sheet of wood (often less than a millimeter for antique furniture) glued to wood or plywood. If we look at the cabinet from the outside, we see that the appearance of the top and sides is identical to the uprights and drawers. As we saw when turning the cabinet over, these elements are made of plywood, so it cannot be solid wood: oak veneer was therefore used and placed on the exterior faces.
3 / How to sand wooden furniture? Before you start
To sand a wooden piece of furniture, place the piece of furniture on blocks to raise it slightly (simple wooden cleats are very suitable). This will allow you to sand the bottom of the cabinet easily.
If your sander has a construction vacuum connection, use it! You will breathe less dust, and sanding will also be easier as dust will not stay on the parts you are working on. If you tinker regularly, this is the best investment to make, in my opinion! By the way, it has also become my vacuum cleaner for the household. I find it much more efficient than household vacuum cleaners 🙂
4 / How to sand wooden furniture? The first sanding of large surfaces
The main element for good sanding is the sander! To find your way around the different types of sanders to use and make your choice, I give you all my advice in this article. I always start sanding with large, flat surfaces. Here, the top and the sides.
To sand solid wood: it is the easiest to sand. Due to its resistance, we can afford to remove material and go a little “hard.” I use a coarse grain for this type of sanding (60 or 80 depending on the “tenderness” of the wood), the turbo function of my sander, and a high speed.
To sand veneer: sanding veneer is much more difficult. There is a risk either of peeling off the sheet or removing too much material and revealing the plywood underneath. I sand the veneer with an average grain of 120 maximum (and I advise you to start at 180 and see if it is sufficient), with a low speed if you have a variator. The goal is to remove as little material as possible. If you are sanding with an eccentric sander, put the pad on the wood first and start the sander.
For this step, several passages may be necessary. The goal is not to get a nice finish but to roughen and expose the wood. If you want to paint your furniture afterward, you can sand superficially: the idea is to remove part of the finish and scratch the surface enough to hang the undercoat of paint. If you want to leave the wood exposed, a more meticulous and deep sanding is necessary to recover a beautiful uniform wood.
5 / How to sand wooden furniture? The first sanding of angles and grooves
The eccentric sander does not allow you to sand angles, edges, and parts such as drawer rails or moldings. For this, 2 solutions: the triangular sander and sanding by hand.
The triangular sander:
For corners or more difficult-to-access parts, I use a vibrating triangle sander. Here my eccentric sander turns into a triangular vibrating sander by changing the sole. I also use it for sanding the curved parts. If you don’t have one, you can, of course, make do with manual sanding.
For the rest, I sand by hand! I use canvas sandpaper for this, which can bend and curve without tearing. For the moldings, I fold the paper in half. Stretch it with both hands, and I “slide” the form in the grooves. Remember to vacuum regularly or remove dust with a rag while sanding.
6 / How to sand wooden furniture? Finishing sanding
Once all the furniture has been sanded for the first time and the original wood exposed, it is necessary to refine the sanding for a nice uniform finish. I, therefore, respond to the piece of furniture with a finer grain by repeating steps 3 and 4. For this step, touching wood is essential: this makes sure that no place is forgotten. You will see, you will immediately feel the difference under your palm: the wood becomes smoother and softer.
If I started with an 80 grit, I would go back to grit 120, 180, and 240. If you plan to paint the wood, you can stop at grit 180 or 120. Indeed, the undercoat will stick as well, and when you apply it, the wood fibers will stand on end. It will then be advisable to sand with a finer grain (240) between the application of the coats to find the “softness” of the wood.
After all these steps, the sanding of your furniture is finished! All you have to do is dust it carefully with a vacuum cleaner and a slightly damp cloth and move on to a painting or applying a finish. If you want to leave the wood visible, I advise you to use a finishing oil. You will find all my advice in this article. If you opt for a painting, you can also find my ideas for revamping a piece of furniture with paint.