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How to use an orbital sander

Orbit sanders may seem like a relatively new addition to the power tools isle in your local hardware store but in fact they are the grandfather of all sanders. Their history relates back to when the first electrical drills were introduced and the orbital sander was simply an attachment that fitted in to the drill and had a sanding pad on its end. This pad would then be rotated by the drill and would form a crude orbital sander. At the time this type of sander was considered very hard to use because the powerful drill rotating the sander in a regular and circular motion made it very hard to control. It also meant that circular marks and gauges were very common.

Today this concept has been adapted into what we know as the random orbital sander. the big difference with today’s sanders is the way that the disks rotate – as the name suggests the rotation is random thanks to not only the rotating disk but also an oscillating motion that comes from the sanding unit. The two oscillating motions combine to make a random movement. And it is this random movement that helps to avoid gouges and circular markings on the surface being sanded.

In addition to this, many orbit sanders also have vibration reduction features that help to make the sander easy to control, light and this allows the user to have more control over the sanders movement and allows for a very fine finish to be achieved.

How to Use an Orbital Sander

Preparation

As always, preparation is key. Before you start work make sure that you are fully prepared, being well prepared makes you more comfortable when sanding and avoids you getting stressed out, which can result in the job being rushed. Prepare the following equipment before you start work –

5 Tips for Achieving a Perfect Finish with your Orbital Sander

Secure the Sanding Disk or Pad

Most orbital sanders today use the hook and loop system, this makes securing the sanding pad very easy but even so you should ensure that the pad is firmly secured to the device. It is important not to over-use sanding disks because when the hoops on the back of the pad become clogged up with debris and dust the grip becomes less effective and this can result in uneven sanding.

Use Ventilation

Ventilation and dust extraction is very important when using your orbital sander. Not only does it make for a safer working environment but debris and dust can also have a negative effect on the surface being sanded. The best orbital sanders tend to come with dust collector fittings that will aid in the removal of dust as you are sanding. This helps to keep the surface that you are sanding clear from debris and makes it more likely that you will get a clean finish, it also makes it easy to see the progress of your work.

Keep the Sander Moving

Once you start sanding, keep the orbital sander moving constantly – although most orbital sanders have their own random action, if you keep the unit moving as well it will provide an even smoother finish to the area that you are sanding.

Maintain a Constant Level of Pressure

In order to get the best results from sanding you should maintain a constant level of pressure to the surface you are sanding. If you press too hard the unit will slow down and become less effective, also if you press too hard it is likely that you will not be able to maintain that pressure and this can result in an uneven surface area. So keep a light but firm pressure on the sander at all times.

When you start sanding, make sure that you let the sander spin up before touching down on the surface. Unless you have a random orbit sander with automatic speed control.

Equally, when you finish sanding make sure you let the sander spin down fully before you remove it from the surface – and crucially, before you stop moving the sander.

Keep the Sander Level

Although you can use an edge of the sanding pad it is preferable to keep the full pad area on the surface as you sand – this ensures a smooth sanding action and it also allows the power of the sander to be equally distributed over the entire sanding pad.

How to Sand a Wall

First of all assess the wall that you are going to sand, depending on its condition, level of smoothness and surface type you should be able to pick an appropriate sand paper.

Remove as much lose material as possible from the wall before sanding. For example if the wall has had wallpaper on it, remove as much of this as possible first. Sanding a wall that still has loose material attached to it will result in the sander becoming clogged up and this will make the job much harder.

When you start sanding the wall, make sure you keep the full surface of the orbital sander in contact with the wall at all times. Whilst you are sanding, move the sander in a circular motion and never allow the sander to remain in a fixed position whilst it is spinning.

Do not be tempted to push too hard on the sander – orbital sanders actually work best when they make only light contact with the surface being sanded and the weight of the orbital sander itself provides adequate pressure to the surface being sanded.

Let the rotating disk do the work – some sanders spin at speeds up to 12,000 rpm – that means the sanding disk is spinning round 12,000 times per minute. Adding pressure to this will normally result in the sanding disk slowing down and this makes it far less effective.

Be patient – if it looks like the sanding isn’t going well, its easy to think you need to apply more pressure, but don’t. instead be patient and let the sander do its job slowly and efficiently.

Don’t use the same pad for too long a period – if the pad feels smooth then you should change it for a new one – once debris and dust gets ingrained in the sanding pad it will become less effective.

How to Sand Plaster

Plaster is considered a relatively lightweight material when it comes to sanding. For this reason you should be very careful when sanding plaster. It is very easy to create imperfections and gauge marks on plastered surfaces if you sand the area with too much pressure or an uneven surface.

For this reason you should select a finer sand paper for sanding plaster – if the surface is relatively smooth to begin with then you can use a medium sanding disk (120-150 grit).

If the plaster wall has visible imperfections or gauges then you can use a more course sanding disk (80-100 grit).

When you are sanding a plaster wall it is even more important to let the orbital sander use its own weight and not to put any additional pressure down on the sander. Also you should keep the sander moving at all times, using a circular motion as you sand the plaster wall.

These techniques combined will ensure that you sand the plaster wall very slowly and evenly and will help to avoid gauges and uneven areas on the plaster wall.
As the walls surface becomes smoothly you can gradually reduce the coarseness of the sanding disks by changing to higher and higher grit ratings – remember the higher the rating, the lighter the sandpaper and the smoother the finish that will result.

How to Sand Hardwood Floors

If your floor is made from solid hardwood then you can safely sand it using an orbital sander. If your floor is made from engineered hardwoods then it may not be safe to do so because the wood may become visibly damaged when you sand it – because it consists of several wood layers. If you’re not sure if your hardwood floor needs refinishing, put a few drops of water on it. If the water beads or soaks in slowly over a few minutes, you probably just need a good cleaning and polishing. However, if the water soaks in immediately, it’s time for a refinish.

If your floor is damaged, stained or has wax over the finish, you’ll need to sand to bare wood.

When sanding a hardwood floor you should sand in several stages, each time using progressively lighter sanding disks. First of all use a course sanding disk (30-40 grit), then a medium 50-60 grit and finally a fine 80-100 grit or higher.

Doing this in stages helps to provide the finest possible finish to your hardwood floor whilst also ensuring that you will remove all imperfections from the surface.

It is also very important when sanding wood that you sand with the grain – instead of sanding in circular motions like you would on a plaster wall, sand in forward motions following the grain of the wood. This helps to avoid scratching the wood surface with the sanding disk.


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