Smoothing wood isn’t all that difficult. It’s just a case of choosing the right tools and employing the correct technique.
In order to get a smooth finish on wood, you should start with rough sandpaper that has a grit of 40 to 60. Next, move on to medium-grit sandpaper that’s 80- to 120-grit. Finally, finish sanding with fine-grit sandpaper between 150 and 180 grit. Using an oscillating hand sander may result in a smoother finish.
This guide is going to take you through the step-by-step process of sanding wood for a professional finish. There’s also advice on what to do if you need an alternative to sandpaper.
How to Make Wood Smooth
Hardwoods have dense grains that cut well, but these still need some minimal sanding to remove any saw marks. With hardwoods, you can skip to a higher grit number of over 300, giving you a smooth surface.
Softer woods like pine will have a rougher cut, and sanding needs to start with sandpaper that’s 200-grit or lower. Finish off all woods by hand-sanding with a higher grit on a sanding block.
How to Get a Smooth Finish on Rough Wood
For wood with deep scratches and grain, you will want to invest in a belt sander. Sanding by hand will take a long time, and it is far more difficult to perform level sanding by hand. You will also want to fill in any holes or cracks in the wood before you begin.
- Start with a grit paper below 60 to even out the worst of the wood. You can be more aggressive at this stage, and using a power tool like a belt or disc sander will help.
- Once you feel that the sandpaper is no longer improving the surface, you can move on to the next level. Double the grit each time you progress, so use a grit of less than 120.
- By this stage, you should be looking at light scratches from the sandpaper, and you can move on to the sanding block. Double the grade again, to a grit of less than 220.
Sanding blocks prevent your fingers from pushing down unevenly where there are patches of denser wood. The block will also reduce scratches, where the sandpaper would otherwise crease up in your hands.
How to Smooth Wood Without Sandpaper
It may be a Sunday, and the shops are closed, or you have environmental concerns that stop you from using manufactured sandpaper. There are many ways that you can sand wood without using sandpaper.
Sandpaper alternatives include:
- Sand – Lay the wood down flat and sprinkle the sand over the area. Then rub the sand in with a heavy cloth or an old leather belt. Quick but messy.
- Walnut Shells – Crush the shells down with a hammer, then put a hand full on the wood. Rub in with a heavy cloth. Great for final polishing.
- Corn Cobs – crush the cobs down with a hammer, then work them into the surface of the wood. This is another clever way of polishing wood without chemicals.
- Pumice – Natural volcanic rock that breaks down as you rub it over the wood. Great for wet sanding, though expensive and difficult to create a flat surface on the wood.
- Rottenstone – Offering a finer grit than pumice, but it is less expensive if you can find it.
- Wood Shavings – The larger shavings of wood you get from cutting or planning make effective sandpapers. You need to remove any debris from the shavings, such as grit before you begin.
- Wood File – You can buy metal files with varying grades of coarseness. These are flat, consistent, and will last a lifetime.
- Planer – Planers use a sharp metal blade to skim off the surface of the wood. A planer will give you precise control over the amount of wood you take off and a perfect surface.
- Burnishing – When you want to achieve a finer finish than possible with sandpaper, you can use a leather strip, a piece of wood, or a section of metal. Rubbing the materials against the wood will give you a smooth finish.
- Glue – Glue sand to a flat block of wood, metal, or stone to create your own sanding block. You need good glue that will not peel and fine sand.
How to Get a Smooth Paint Finish on Wood
Paint streaks and bubbles are the enemies of a smooth paint finish. So how do you prevent brush marks when painting wood?
1. Prepare the Surface
The more you smooth out the wood before you paint, the easier the paint will go on, and the better the finish. Fill small dents and holes, as these will leave drip marks. Sand everything, moving up in grades of sandpaper until you achieve a smooth surface.
If possible, try to sand along the same lines as the grain in the wood – this helps to reduce grain marks. Brush off and vacuum away the dust; it may help to use a damp cloth to remove the finer particles.
Primer seals in the wood and prevents moisture from the paint and the air from warping the wood. Some paints contain primer, so you can paint straight onto the wood. The instructions on the paint or primer may tell you to thin out the mixture before applying it to the wood – follow them.
Thinning out the mixture makes it easier for brush streaks to settle. You can also try spraying on the paint or primer, but you need to be careful not to overspray as this will cause drips to form. Keep the coats thin and even.
Sanding sponges are useful tools in preparing the primer or first coat for paint. A sanding sponge will remove small imperfections, drips, and thick spots. Roughing up the area will also help with the adhesion of the paint.
You may spot some areas that you missed with the primer; this is the time to touch up any dips in the coat. Once sanded, you can vacuum and wipe off the surface with a damp cloth, to remove all the dust.
Give the wood a second coat and wait for it to dry. Then use super-fine-grit sandpaper to smooth out the paint. Wet and dry sandpaper works well on gloss paint by removing any small brush marks.
You can continue with up to four coats of paint and sanding with fine-grit paper. After this, you need to apply a protective coat that will seal in the colors and protect the surface from chipping. Polyurethane or polyacrylic sealers work well on dark-painted wooden furniture.
You may not like the chemical smell of these sealants, and instead, you can use natural sealing wax. These waxes work with a single application, and any excess is easy to wipe off.
How to Make Wood Shiny and Glossy
A high-gloss (lacquer) finish will make furniture look new and make it easier to clean. The treatment will also help to preserve the wood for longer, meaning less maintenance.
How to Get a Glass-Like Finish on Wood
This treatment will work on all types of wood. It can be a big undertaking to reach a mirror finish on your furniture, but it is possible if you follow these steps:
- Sanding – Start with coarse sandpaper and work your way down to fine grit. Sand in the direction of the wood grain. A power sander will speed this up.
- Clean – Wipe off the dust from the wood with a damp cloth.
- First Coat – Apply the first coat of varnish and leave it to dry. Air bubbles will appear as it dries. You will also have small splinters and bugs trapped in the varnish – pull these out, pop the bubbles, and sand.
- Second Coat – Thin out the second coat so that it settles evenly. Remove any stray brush hairs as you go.
- Polish – Leave the last coat to dry for more than two days. Then you can polish the wood with automobile polish. The polish with go cloudy when it dries; this is when you can rub off the excess with a clean cloth to reveal your mirror finish.