You’re probably wondering – Should you sand between coats of stain? The question of sanding between coats of stain is a hotly debated topic. Many people say you should, others say you shouldn’t. But what does the research show?
We set out to find an answer and we’re going to share our findings with you today! If this sounds interesting, keep reading to learn whether or not it’s worth your time to sand between stain coats.
Time to kill the suspense;
Should you Sand Between Coats of Stain?
No, sanding between coats of stain is only mandatory when using water-based stains. You need to sand down every raised wood grain. However, when using other types of wood stains, you only need to sand the surface before applying the first coat of stain.
Sanding between coats of oil based stain
Sanding between coats of oil-based stain isn’t necessary because oil-based stains have a longer open time before it dries. This means it allows you enough time to wipe off the excess stain using a rag and even out any potential flaws or bubbles.
How to Sand Between Stain Coats
When working with a stain that demands some sanding between coats, you need to do it right. If you over sand or use the wrong sandpaper grit, you could end up ruining what you had accomplished already.
So, follow these steps, and let’s help you achieve a uniformly neat finish for your projects.
Steps for sanding in between coats of stain
First, choose a high grit sandpaper number (220-240). This fine sandpaper grit will smooth out any developing imperfections. If you use lower grit sandpaper, you will tear into the stain and end up with difficult scratches to remove.
Stay away from sanding between stain coats using steel wool unless it’s a large area.
Use a sanding tool to ensure you sand the surface evenly. If you don’t have any, improvise with a block of small scrap wood you can wrap the sandpaper around. Still, you can use your bare hands to hold the sandpaper.
Lightly sand the stain coat in the direction of the wood grain. Make light passes from end to end of the wood project. You’ll notice some dust on the sandpaper and the surface.
Slowly run your palm on the sanded surface; if it’s all smooth and soft, you can stop sanding. If the opposite is true, the surface may require further light sanding.
Vacuum the dust off the surface and then wipe further with a dry cloth. If you’re working with oil-based stain, soak the cloth in mineral spirits and wipe it on the surface to ensure no dust is left behind.
Avoid using a cloth dampened with water to wipe off sanding dust from wood. The water will raise the wood grain: forcing you to sand all over again.
Types of Stains and Whether you Should Sand Between them
Sanding between coats allows the first coat and the second coat to bond well and finally give you a better finish. However, note that all stains require sanding before the first coat is applied, but only one type should be sanded between each layer.
In the coming section, we’ll find out the details of the various wood stains and at which stage sanding applies to each of them.
First on our list is the oil-based stain. It is one of the most popular stains among woodworkers. Sanding is particularly needed during the wood preparation stage. Ensure you smooth out any grooves and scratch marks using very light sandpaper.
For this stain, you don’t need to sand between coats of this oil stain. Instead, apply a thin layer of oil stain on the wood surface and wipe off excess using a clean rag.
If you want to stain wood darker color, apply multiple layers of the stain and let the previous coat dry fully before the subsequent ones.
Water-based stain is the only stain that requires sanding between every coat except the top coat. This is because the water content in this stain raises the wood grain: which you need to sand down if you are interested in a smooth surface and beautiful finish.
In which case, you need to use a light sandpaper grit of 220 and above. Then wipe the sanding dust using a dry cloth.
Like the oil stains above, you don’t need to sand between coats of gel stain. The only sanding your wood needs with this product is during the preparation stage.
Gel stains are usually thick and have a paint-like consistency, and tend to sit more on the surface than it penetrate the wood pores. So when applying gel stain on laminate cabinets or wood, don’t sand after first coat of stain.
Lacquer stains join the group of stains you don’t need to sand in between coats. The behavior of this product differs a bit from the rest: it can melt into the previous layer of lacquer stain and adhere so well.
If you notice any unevenness on the surface with lacquer stains, you can wipe or rub gently with a clean cloth to smooth it out before applying the last coat.
Polyurethane stain is also known as varnish stain. It comes in water-based and oil-based stains. You don’t need to sand after any coat for both of these types because they are fast drying. This also implies that you can wipe off any excess stain or imperfections as soon as you notice them!
Metal-Complex Dye Stain
Metalized dye stain is stronger and more durable for dense wood and outdoor finishes because metals such as copper and chromium are added to make the dye more resistant to fading.
The metals used in this stain are non-grain-raising; meaning you don’t need any sanding between coats.
Water-Soluble Dye Stain
As the name suggests, this is a wood stain available in powder form. To make it work dissolve the powder dyes in water using the recommended ratio of one ounce per one-quart water. Add more powder if you want deeper pigments.
Given that this stain is water-soluble, you may need some light sanding between coats.
How Long Should Stain Dry Before Sanding?
Given that water-based stains are the type that allows sanding in between, you want to ensure the surface doesn’t feel wet or cold when you place your palm on it. This is one of the tests to tell when the surface is dry enough for sanding or the next coat.
Another reliable way to tell if the stain is dry enough to accommodate some sanding is to let it sit for about an hour to four hours relative to the humidity levels in your region.
Also, you can sand a small inconspicuous area. If the sanded part turns whitish and some loose dirt gets trapped in the sandpaper, you can go ahead and sand over the entire stained surface.
Generally, it’s good to rely on all the methods above for accuracy when determining if the stain is dry enough for sanding.
How Long to Let Stain Dry Between Coats
Let the stain coats dry between four to eight hours or more, depending on the stain you choose. You want to make sure the previous coat is sufficiently dry to the touch before applying the next coat.
Furthermore, the manufacturers indicate the recommended amount of time between stain coats you should wait; adhere to that. This drying time allows for proper stain absorption and gives you a better finish.
For further reading, see our blog post on when to apply a second coat of stain to get the desired results.
Do you have to Sand Before Staining?
Yes, you need to sand the wood surface to even out scratches, dings, and other blemishes that the stain would highlight. Sanding also opens up the wood pores allowing the stain to penetrate it properly. If you skip sanding, the wood might not absorb the stain as it should.
Can you Sand after Staining?
Yes, you can sand after staining to even out any bubbles and raised grain. However, you would need to use finer grit sandpaper starting from 220. This grit is perfect for the light sanding task. Note, however, that not all stains need to be sanded after they’ve been applied.
What Grit Sandpaper for Stained Wood
220 – grit sandpaper is perfect for sanding on stained wood. When using this fine sandpaper, make light pass along the length of the stained wood. Also, make sure to sand wood in the direction of the wood grain.
Do I Need to Sand Stained Wood Before Applying Polyurethane
You don’t need to sand after staining before applying polyurethane. You only need to allow enough time for the stain to dry before applying polyurethane. But, if you are a perfectionist, you can feather sand the surface using super fine-grit sandpaper(400-500).
Sanding between coats of stain
Sanding between stain coats is only applicable to water-based stains to help you eliminate any raised grain and imperfections. However, sanding raw wood before staining is a requirement for all stain types.
Knowing whether or not you should sand between stain coats is an ace up the sleeve for every woodworker who likes to DIY home improvement projects.
Always read the manufacturer’s manual for further guidance. Good luck with your staining project.