Have you ever wondered why you need to sand furniture and what exactly sanding actually do? Do you have to sand furniture to prepare it for painting? Can you ahead and paint it without sanding? This guide will answer all of your questions!
First, you must understand what sanding actually does. Sanding wood furniture will do the following things:
Remove flaws such as mill marks, caused by woodworking machines, dents, gauges and any other surface damages
To ‘rough’ up the surface of your furniture so that paint will adhere to it. This is especially important if you are going to paint a high-gloss or laminate surfaces that are too smooth for the paint to stick onto.
With that being said, do you need to sand your furniture?
Do you NEED to sand?
You MUST sand your furniture if:
It is damaged or chipped
It has any rough, uneven or bumpy spots or surfaces
If your furniture isn’t in any of these conditions, there isn’t a NEED for you to sand. It is a matter of preference but there are plenty of alternatives that you can choose from if you want to avoid sanding and paint your furniture. I will cover this in the last section.
When should you AVOID sanding?
This might come as a surprise to some as sanding furniture is never bad. A little sand goes a long way after all. But in fact, this is a piece of crucial information that everyone should know.
You should NEVER sand your furniture if it contains LEAD or is coated with lead-containing paint. At this point, you might have no clue if your old furniture were painted in lead paint.
No worries, you can purchase an inexpensive testing kits to test for lead at your local store or here.
If the test shows that your furniture contains lead, stop here and read the following articles on how you can remove lead paint and refinish safely.
Preparation for sanding
Before you start sanding, you have to equip yourselves with the proper tools and prep your furniture first.
Sanding is a messy process with dust and debris flying everywhere. It doesn’t give off toxic chemical fumes, but you still need to sand in a well-ventilated area and put on safety equipment.
Here is the safety equipment that you would need:
Dust mask/ Disposable Masks/Respirator
Cleaning tools for the dust
Remember to clean the dust BETWEEN sanding, not just at the end of the whole process. The debris caught under the sandpaper can actually damage and scratch the wood. We don’t want that!
Forget about using your rags or brushes to clean the dust. It isn’t that effective. Instead, use a tack cloth which is relatively inexpensive and is made for the purpose of removing dust.
If you are using an electric sander, a genius way to greatly reduce the dust is to attach a vacuum or a dust-catching tool to the adapter of the electric sander.
Salvaged Inspirations detailed this step so well in her post here. Like what I always say, conquer the dust before it conquers you!
Wood Filler (if required)
Before you start sanding, check if your piece has any cracks, gouges or dents. If it doesn’t have any of that, skip this section and go to the next step. If your piece has any of that, fill them in with wood filler.
HOW TO USE:
Pick a wood filler that matches the colour of the wood as closely as possible.
Fill in any crack/gouges/dents with the wood filler all the way ABOVE the brim, such that it is higher than the surface of the wood. But not too much that you have to sand a lot of it off later.
Let the wood filler dry for 48 hours or as stated on the label of the product.
Sand the dried wood filler down to make sure it is level with the surface of the furniture piece.
Sandpaper, Electric Sanders and Hand-sanding
How do you choose which sanding equipment to use? Do you use sandpaper or electric sanders? What kind of electric sanders should I use to sand furniture? There are orbital sanders, palm sanders and mouse detail sanders. Also what grit or grade of sandpaper should you use? Every tool serves a different purpose for different kinds of features, wood and furniture. Let’s find out which is the most suitable sander for your furniture!
Rule of thumb: The higher the number of the grade/grit of sandpaper, the finer it is. The lower the number, the coarser the sandpaper.
Coarse grits (below #100) are meant for heavy to moderate stripping of paint. This grit is NOT suitable for delicate antiques and fine wood finish as it would be damaging to the wood.
Medium grits (between #100-#150) are meant for removing scratches or old finish on bare surfaces. It’s great for levelling out and smoothening the surface of the wood.
Fine grits (#180 and above) are meant to be used between coats to smoothen the surface.
Finer grits (#320 and above) are ideal to give a final finish to the furniture piece before staining the wood.
There are various kinds of electric sanders to sand furniture: belt, orbital, palm and mouse detail sanders.
For wood furniture, we don’t usually use belt sander as it is too heavy-duty, and it is meant for a heavier carpentry project. You can use belt sanders if your furniture has large surface areas but always make sure to hold tight to the handle as this power tool would zoom across the surface like the Flash!
The most common sander for home projects is a palm sander! It is lightweight and ideal for wide, flat surfaces. You can use this for almost anything in your home that you want to refinish. It is a great, all-around sander!
For pieces with intricate woodwork or corners (such as the underside of a table), a mouse detail sander is the tool for you. Detail sanders have a triangular base with a pointy tip of one side, and it makes it easier for you to reach into corners.
Hey, so what about orbital sanders? You might ask. A Google search shows many different takes on how you should use orbital sanders to refinish furniture.
First, you need to understand that there are 2 kinds of orbital sanders: the regular one where it moves in a circular motion and a random orbital sander that moves in… well, random motion, as the name suggests.
For the regular orbital sander, it sands your furniture against the grain of the wood and this would often result in ugly round marks or grooves on the surface. Many sites suggest using a mouse sander afterwards to finish it in order to sand it along the grain and remove these round marks. The round marks are especially noticeable when you stain the wood.
To solve this problem, use a random orbital sander instead! This would give a smooth finish and it would not cause any cross-grain problems. But do take note that the random orbital sanders are more powerful than the regular one and will take off more material off the wood if you are not careful.
IMPORTANT NOTE FOR ELECTRIC SANDERS: Never push down on the sander while you are using it and never leave it in one place for too long. You will leave behind a groove on your furniture that will be much harder to cover up! Always keep it moving!
Regardless of which electric sander you choose, you will always need to do a bit of hand-sanding. You absolutely need to use hand-sanding for any fine finishes and features, hard-to-reach areas and delicate furniture. Basically anything that isn’t a flat surface and is hard to reach, you need to sand it by hand.
The best way to hand-sand is by using a contoured sanding block or wrapping a sandpaper around a block of wood or a sponge that fits nicely in your hand.
The best thing about hand-sanding is the versatility of the sandpaper and the sanding techniques.
For curved surfaces, wrap the sandpaper around a sponge or a foam padding so that it can shape itself according to the curves. This will allow you to exert even pressure on the piece.
For any narrow round parts, such as rungs, spindles and legs, cut out a strip of sandpaper (fine grit or #180-220) that is at least long enough to wrap across the round part twice. Wrap the strip across the round part and pull the 2 ends back and forth in a buffing motion.
Pro Tip: To exert even pressure, you will need to move the strips up and down the round part and changing your angle as you work. Be mindful of the edges of the strips so that you do not leave any horizontal indentations in the wood.
For carvings, use sandpaper (fine grit or #180-220) without the sanding block and sand lightly. Using your fingertips, press the sandpaper into cutout areas as far down into carving as possible. But be careful not to flatten the wood or the rounded surfaces. Extra care must be taken especially for shallow carvings so that you do not blur its edges.
For nooks and crannies, slip a strip of sandpaper (fine grit or #180-220) into the crevice and ensure that it is creased to fit nicely against it. Sand lightly along the nook in a slow, even motion. Make sure not to sand the edges of the crevice.
For any other delicate features such as veneers and fine patinas, always use fine-grit sandpaper (#180-220) and sand it extremely gently. For extra care, use steel wool instead of sandpaper to smooth the surface. Use No. 0 steel wool if the surface is rough and No. 00 – 000 if it is already smooth.
Reminder: Remember to remove any dust or debris between sanding and wipe it clean with a tack cloth each time.
Recommended Sanding Process
By now, you might have an idea on which sandpaper grit and sander to use for your furniture. Or you might be totally confused with the amount of information here.
Fear not! As a generic rule of thumb, you can follow these following steps to sand furniture if you are unsure which is the best for you:
Use a palm sander (medium or #80-150) to remove the old finish and scratches/surface damages.
Stop when you can see the bare wood.
If you still don’t see the bare wood despite sanding it with the palm sander several times, try a random orbital sander instead.
Change the sandpaper on the palm sander (or whoever sander you are using) to a finer grit (#150 -200) to remove any leftover finish, stain or paint. Do this until the whole furniture piece is bare.
For fine finishes, delicate pieces or hard-to-reach areas as mentioned above, hand-sand it with a sandpaper/sanding block/ sanding sponge (#180-220)
Finish the whole piece with hand sanding (fine grit or #320 and above). This step is especially important if you will be staining the furniture.
Golden Rule of Sanding
Regardless if you are using an electric sander or hand-sanding it, the golden rule to abide by is to always sand WITH the grain of the wood, and never against it. Sanding against the grain of the wood, also known as cross-grain sanding, will cause permanent and noticeable scratches on the wood.
Standard sanding technique:
Ensure that the surface to be sanded is in a horizontal position and at a comfortable height
Don’t hold the sander or sandpaper perpendicular or at an angle to the wood
If using an electric sander, ensure that it is flat against the wood and apply even pressure. Don’t exert excessive pressure.
If you are hand-sanding, use a sanding block or a sandpaper-wrapped wood or sponge to be able to exert even pressure.
Hold it flat against the surface of the wood and move it back and forth in the direction of the grain and in long, even strokes.
Make sure not to press too hard.
Change the sandpaper once it is filled up with too much debris or becomes too smooth
Standard rule for sandpaper grits:
Work from coarse to finer grades of sandpaper.
The first grit to start with largely depends on the material. Use #80 for extremely smooth surfaces, such as laminate, #120 for most woods and #150 for soft woods (e.g. pine)
The first coarse grit will remove most of the old finish/scratches, then sand out the scratches left by this coarse grit with finer grits until you reach the desired smoothness.
There is no golden number for how fine the grit should be for the last sanding. One thing to remember is to stop sanding once the surface reaches the smoothness that you want.
When in doubt, stop at #220 grit.
Raising the Grain (optional)
Some people do this, some do not. But if you are a perfectionist like I am, this step will make your furniture as smooth as glass!
Note of caution: Making the surface too smooth can actually backfire and make it difficult for the stain or new finish to adhere to it. So, skip this step if you are planning to stain or paint the furniture. It really depends on the final look you are going for.
When wood gets wet, the cells would swell and cause the grain of the wood to rise above the surface. This will cause a raised grain appearance.
To prevent this, an age-old technique is to wet the sanded piece with cold water.
Soak the wood with a sponge evenly and wipe off any excess water.
Let the wood dry completely. This would take around 3-4 hours or overnight, ideally.
Once the wood has dried thoroughly, you should be able to see the raise wood fibers of the grain rising above the surface.
Use your last-used sandpaper or a slightly finer one and sand down these fibers. For very delicate surface, use No. 000 steel wool to smoothen it.
Remove the dust and debris with a vacuum or brush and wipe it clean with a tack cloth.
Do you still need to use primer after sanding?
It really depends on the material of your furniture.
For example, for laminate furniture, the surface is extremely smooth. So, after sanding the surface with coarse-grit sandpaper (#80), I would use a primer before painting just to be safe and ensure that the paint sticks.
That is not to say that the paint wouldn’t stick to the laminate furniture without a primer. But adding a primer into the mix would certainly give extra insurance.
Alternatives to sanding
Let’s take a look at the alternatives to sanding that you can try if your furniture is in great condition and you want to prep it for painting.
Paint Deglosser/Liquid Sandpaper
If your piece has a glossy, semi-glossy, shiny, satin or any slick finish, you HAVE to remove that glossiness before painting it.
There are 2 ways you can remove the gloss or shine of furniture:
a) By sanding it, as previously stated.
b) By using a paint deglosser. If your piece is in great condition and you ONLY need to remove the glossy finish, a paint deglosser can do the trick.
A paint deglosser (also known as liquid sandpaper) is a chemical solution that preps the surface of the furniture for painting by dulling the paint or varnish. This ensures that the fresh coat of paint will stick to the surface of the piece.
You can use a paint deglosser on:
Any detailed moulding or appliques
Any delicate pieces
Any intricate or curvy furniture features
Any narrow areas where sanding would be tough or time-consuming
Any pieces painted with anything that could cause harmful dust such as lead
HOW TO USE: Wet a sponge or rag with the liquid sandpaper and wipe it over the whole furniture piece until it feels slightly sticky.
SAFETY MEASURES: As with any chemical solution, you will have to take proper safety measures.
- Equip yourselves with gloves and safety goggles, and work in a well-ventilated area.
- As the chemical is flammable, make sure the rags or sponges you use are fully dry before you dispose of it afterwards.
Aside from paint deglosser, you can also use a bonding primer to prep your furniture for painting. A bonding primer creates a rough surface on your furniture, allowing the paint to adhere to it easily.
It works not just on wood but also on metal, vinyl, tile, oil-based paints, lacquer, varnish. Plus, it helps to seal water stains!
HOW TO USE: You just need to brush one coat of the primer over your piece and it will dry within an hour. As easy as that.
What if you do not need to sand and you want to avoid any prep work?
So your piece is in great condition and you don’t need to sand it. You also don’t have time to prep it with a paint deglosser or a bonding primer. No worries, there are 3 prep-free options for you where you can get on with the painting right away!
Milk Paint + Bonding Agent
Mix milk paint, a non-toxic and biodegradable paint, with a bonding agent in EQUAL parts and you can immediately paint your furniture with it!
How does this work? Well, the bonding agent acts similarly to a bonding primer except you can actually mix it with the paint directly. A 2-in-1 deal!
I’m sure you have heard about the miracles of chalk paint and its adhesion to furniture without any prep work. But take note that chalk paint has a super matte finish!
Similar to chalk paint, mineral paint requires no prep work but it is so much more durable and waterproof! There’s a price to pay, of course, for that durability. It’s pretty expensive as compared to the other options stated here.
More on painting furniture in my ultimate guide in choosing the right paint for furniture!
I know this is a lot of information on sanding furniture to digest, so I tried to break it down in the infographic below. I hope this comprehensive guide on sanding furniture is able to help at least one of you understand a bit more on how to sand furniture and apply it to your furniture revamp projects! I would love to see it too, so don’t be shy to share it in the comments!
I have done a guide and infographic on stripping furniture and choosing the right paint for furniture where i compared latex, chalk, milk, mineral, oil and enamel paint! I am currently working on more guides for furniture waxing and staining! Keep up to date with the latest furniture craft tips and infographics by subscribing to my newsletter below!