How Do You Know When Sanding Is Done

Published on: April 8, 2022
Written by Eric Devin / Fact-checked by David Rowan

Maybe sanding is the most crucial, time-consuming but neglected part of a woodworking project. As the process is lengthy, it makes the woodworker restless to finish off the sanding process and straight go to staining. 

But it is hard to tell if the sanding is done perfectly on the dry wood. As wood looks smooth while sanded, it can still have imperfections in it. Imperfection always becomes stand-out when the wood is stained or painted. But there is no way of going back to fix those left-out areas.

So, it is a must to check if the sanding is done, and will not be needing it any time soon. For your convenience, all the tips to check for sanding mistakes and tricks to perfect sanding are unlocked here. 

What Safety Measures Should be Taken When Sanding

1. Wear eye protection such as safety goggles and a dust mask.

2. Make sure the sandpaper is the right grit for the material being worked on.

3. Keep the sanding area well-ventilated.

4. Keep the work area free from debris.

5. Use a vacuum cleaner to keep dust levels down.

6. Wear gloves to protect your hands.

7. Maintain steady, even pressure while sanding.

8. Use a dust collection system when possible.

9. Never leave the sander unattended while it’s running.

10. Disconnect the sander from power when not in use.

How Do You Check for Sanding Marks Before Staining?

Inspection of your wooden workpiece is vital before staining. Because scars and scratches become prominent after staining, varnishing, or painting. It is quite impossible to sand on a stained wood without ruining the stained surface. So, better check the sanding mistakes before actually starting the staining. 

There are two ways to check the finishing of a wood piece. No matter which way you choose, first make sure that all the dust and debris is cleared from the surface. Checking for scratches is best when the wood is cleaned. 

Using Light

This way, the flaws of the sanded wood are checked using a trouble light. You can use this one or any other source of light and use it close to the workpiece. When the light is at the edge, any uneven pattern of marks will cast a long shadow. This is how you can tell where more rubbing is needed. 

Using Water

To be honest, it is extremely prohibited to use water on raw wood before staining. That is because it needs to be dry to be stained. However, we are not soaking the wood here for inspection.

Just damp a sanding sponge with water, wring it to squeeze extra water out. Then just wipe out the wooden piece lightly. Wet wood lifts its grain. So, it becomes clearer where there is a small dent or nick. Then use the sandpaper lightly on those areas lightly to even out everything. 

Most Common Sanding Mistakes

Sanding may seem an easy job, but inappropriate sanding can hamper the look of your workpiece. Beginners mostly use sandpapers without any basic knowledge of it and make their hard work go down the drain. Yes, problematic sanding can make you do your project from the beginning again. To avoid that, let’s have a look at the most common mistakes of using sandpaper on wood and ways to minimize those. 

Beginning with a Too Coarse Grit

The main reason for sanding wood is to blend in the imperfections. Using sandpaper lower than 60 grit always makes the surface worse. It starts creating scratches and scars on the wood surface. So, for woodworking, always start working with 60 grit paper at the least. 

Not Maintaining the Chronology

Another common sanding mistake is, jumping off the sanding paper chronology. A perfect sanding begins with 60 grit paper and then gradually raises it to 80, 100, 120, and 200. New woodworkers sometimes misjudge the importance of using 5 or 6 types of paper on the same wood workpiece. 

Missing one or two grit paper and jumping from coarse to fine paper does not help in erasing deep dents. As a result, the woodworker will discover those unfinished areas at the end and go back to fix those with the appropriate grit of sandpaper. The same goes for using sanding belts while using a belt sander. 

Finishing with a Too Fine Grit

It happens when the woodworker starts using sandpapers without knowing their purpose. Sandpapers finer than 220 grit are not meant for wood. If you use too fine-grit sandpaper on wood, then it will close off the pores of the wood surface. Then, if you want to apply the stain, the stain will not seep in. 

Not Using Dust Collector Often

Dust and debris build up underneath the sandpaper. If not frequently cleaned, it starts creating scratches on softwood rather than erasing it. So, always use a dust collector when you use a power sander. If you are doing it manually, then wipe the surface clean every now and then to prevent sandpaper from clogging. 

Not Sanding with the Grain

This problem occurs when a woodworker takes the advantage of using power tools like a random orbital sander, belt sander, or drum sander. The sanding machines move in a specific direction. But the grains of wood change in the same piece of board. 

If you use an orbital sander, then it will create a swirl mark of knots and grains that are against the motion of the sander. Besides, we usually use small wood pieces in a belt sander or drum sander. In this case, there is no problem with sanding according to the grains. 

However, Manual sanding with a sanding block is the better option here. Or you can use a sander that is easier to control like a finishing sander. 

Putting Pressure while Manual Sanding

Do you use a sanding block while manually sanding or just use your fingers? There are differences between these two. If you use a sanding block, then you will make a firm but even pressure on the block. So that it removes material at a fair pace. 

On the other hand, if you use finger pads, then obviously it will not create an even surface. In this case, the sanding will also be improper in your finger gaps. So, use a sanding block to support the sandpaper. 

Frequently Asked Questions

Should You Wet Wood Before Sanding?

One MUST NOT wet the wood before sanding. Especially, if you are dry sanding, it is compulsory to work on a dry surface. Some also prefer wet sanding, in this case, the sandpaper is dumped in the water, not the wood. Removing material from wet wood is difficult compared to dry wood. 

Can You Stain Over Varnished Wood Without Sanding?

Is the varnish still intact or worn off? If the varnish is already worn off like an old wooden floor, then a light coat of stain will soak in the wood to serve the purpose. If the varnish is thick, then staining on it will just make it sticky and useless. A light sanding is perfect to stain varnished wood. It is done just to open up some pores so that stain can be soaked through. 

How Long Should Wood Dry Before Sanding?

Leave the raw wood under the hot sun for 3 to 4 days. If there is any moisture left in that wood, it will evaporate within this time. Wood also shrinks under heat. If you already dry it up before actually working with it, then there is less chance that it will bend over time. 

Final Verdict

Sanding is almost like praying. It takes time, but the patience you show totally pays off! All the time and work you dedicate to a woodworking project are justified by its look. If the wood is well sanded, then it is well appreciated. 

So, try following all the instructions and tips discussed here to avoid mistakes. Then, you will realize that if sanding is done properly, your work becomes flawless.

Read more:

• 9 Wood Finishing Techniques According to Expert Woodworkers!
• Difference Between Dual Action vs Random Orbital Polisher
• Tips for Sanding Polyurethane