Sanding can be a messy task when you work with wood. You end up with a lot of sawdust and debris, and it is an extremely time-consuming job. It might surprise you to know that you don’t always need to sand wood. So, as a woodworker, you need to identify situations where you don’t need to sand wood.
Does unfinished wood always need to be sanded? Surprisingly, no. You can paint or stain raw, untreated wood when the surface is smooth enough. It is also possible to apply paint directly to painted or finished wood by applying a coat of primer first. You need to distinguish when you need to and when you don’t need to sand wood.
Why do we Sand Wood Before Painting it?
The regular practice is to sand wood before we paint it. However, you need to consider a few things before reaching for your power sander or sandpaper. Was the wood sealed or painted previously? How smooth is the surface?
If the surface of the wood had a finish or was painted previously you can do light sanding before painting over it. If not, the new paint that you apply might peel off after some time.
But if the surface of the raw wood is quite smooth and wasn’t painted previously, you don’t have to sand it. Many people think that if you don’t sand the wood before painting it, the paint may not adhere properly to the surface. It is true for many cases, but not in all instances.
So, when you have raw, untreated wood, you can paint directly onto it. Although you may not have to sand it, you might have to apply additional coats to get the desired finish.
Painting Over Previously Painted Wood
Before painting over wood that previously had a coat of paint, it is always better to sand it first. If not, the new paint may not adhere properly to the surface adequately. The same rule applies to wood previously coated with a sealer or varnish.
But if the wood already has a coating of sealer or varnish and the surface is relatively smooth, you might not have to sand it. But in such a scenario, you may have to apply a coat of well-adhering primer to ensure that your paint adheres well to the surface.
What Happens to Wood That is Not Sanded Before Staining
An interesting question arises here about sanding or not sanding wood before staining it. What happens to wood that you stain without sanding it?
If your wood is raw and unfinished, the wood fibers will easily absorb the stain. You will have to keep applying stain but it will continue to seep into the wood and the effect will not be prominent on the surface of the wood.
But if you are painting wood that was previously stained and sealed, then you can apply paint directly on the surface. The reason here is that the wood sealer effect blocks the wood pores, preventing them from absorbing the paint.
Staining Previously Painted and Varnished Wood
If you want to stain wood that was previously painted and varnished, you would have an issue. The paint and varnish would come in the way of your stain. Then, there would be no way that the stain could make direct contact with the pores and fibers in the wood.
In the case of applying stain directly to the wood, you need to sand off the entire coating from the wood which can prove to be a tedious process. On the other hand, if the wood wasn’t sealed but was stained previously, you can apply stain directly.
But ensure that you use the same or similar shade of the previous stain for perfect matching. If the color of the new stain varies too much, the old and new stains might blend to form a non-descript and perhaps undesirable shade.
To Sand or Not to Sand?
You need to decide whether or not to sand unfinished wood depending on certain conditions. For example, if you have wood carvings that you want to look rugged with a distressed look, then you don’t need to sand them.
Remember, sanding not only offers aesthetic value but offers utility as well. If you have a wooden item that you expect to handle frequently, then you need to sand it. You wouldn’t want people to get splinters in their hands from your woodworking creations.
Things to Consider While Sanding Wood
You may look at the aesthetics of sanded wood or you might just want a piece of wood smooth to the touch. Whatever your purpose, there are a few steps required to sand wood correctly. Here are the steps to follow while sanding wood:
Handy tip: Use a variety of fine-grit sandpapers starting from 100-grit and progressing to about 400-grit for the best results.
- Start with a basic orbital sander.
- If you don’t have a power sander, you can start hand sanding with 100-grit sandpaper.
- Gradually move to finer-grit sandpaper, from 220-grit, and then end with 400-grit.
- While sanding, move in the direction of the wood grain.
- Continue the process until you achieve a satisfactory level of smoothness.
- Sanding is a slow and tedious process. Prepare yourself to spend a lot of time for the best results.
- Use adequate protection like face masks and safety goggles while sanding. The dust can be harmful, and even toxic for some woods.
To Sand or Not to Sand Hardwood Floors
Hardwood flooring is a specialized category of woodworking that calls for skill and experience. You might wonder whether to sand hardwood floors after installation. True, your job would be less messy and quicker. But not sanding such floors after installing them is not advisable.
To begin with, by sanding you level the floorboard edges. Also, when you sand new wooden flooring, you prime the surface in preparation for staining or applying a finish. Finally, sanding also helps to fill gaps between the boards which is something that inevitably occurs.
Oiling – A Good Alternative to Sanding
If you don’t sand wood, oiling it is a good alternative. But ensure that you select a suitable type of oil for the application that you are using, and the type of wood. Your choice of oil type also depends on the final location of your project.
For example, consider the choice of wood based on the types of wood. The best oil for rosewood or cedar is linseed oil. You can use tung oil on maple or oak. But if you use beech or ash, Danish oil is a good choice.
The placement of the finished product also determines what type of oil you can use. Linseed oil would not be suitable for kitchenware like a cutting board or say a wooden salad bowl. The reason is simple – it tends to go rancid.
Mineral oils are perfect for kitchenware and even for use on furniture. Avoid using linseed oil or more specifically boiled linseed oil (BLO) on furniture as it sometimes never completely dries and can make the surface of a chair or stool tacky.
We hope you are now clearer on when to sand and when you don’t need to. You can always sand wood. It will only improve the condition of the wood. But there are sometimes conditions when you can omit the sanding operation, saving time and energy for completing your project.
We have covered various scenarios where you don’t have to sand wood. But when you do, you should know how to do it right. So, we provided you with information on the best approach to sanding. Then, finally, we touched upon oiling – a practical alternative to sanding. You will now have more control over how you finish your woodworking projects.