How to Prepare Wood For Staining
Preparing wood to be stained is more important than you might think. When wood isn’t prepared properly, flaws emerge that were otherwise invisible, reducing the quality of the project.
To physically prepare wood for staining, you’ll need to fill any nail holes with wood filler, sand the wood, prep any exposed edges, remove the remaining sawdust, and stir the stain.
There’s a lot here, so lets take a closer look at the details!
Part 0: Why You Need to Prepare Wood for Staining
Take a look at this piece (it’s a cat tree, by the way.)
Do you see the light horizontal lines running across the wood? Those lines were formed during the manufacturing process, and were invisible until I applied stain.
Ideally, I would have sanded all those lines away during the preparation process. But I did a poor job, and so they became exposed when I stained. Now they’re dead obvious, and reduce the quality of the piece.
If you don’t properly prepare you’re wood, this is what happens. Anyone familiar with woodworking will take one look at the project, and know you skimped on the prepwork.
There have been so many times I’ve found pieces on Etsy where the flaws were dead obvious, and could’ve been avoided if the person had just prepared the wood properly!
Part 1: Make Your Staining Plan
Before you even pick up the stain, you should have a plan in place for how you plan to finish the piece. And I don’t just mean a general idea in your head, I mean that you’ve tested the products together on scrap wood.
Every wood takes stain differently. Finish makes stain look different. Applying with a rag versus a foam brush can change the look. Wood conditioner may or may not be necessary, depending on what you do.
All of these are things you should test before you apply a single thing to your piece. You’ve worked hard to build your project. Why risk getting the wrong look when you can make a quick sample and confirm you’ll get exactly what you want?
Below I talk about the decisions you’ll need to make, and how to reliably test the products you’ve chosen.
Choosing a Stain
There are three types of stain that are generally accessible to consumers: traditional oil-based stain, gel stain, and water based stain.
Traditional oil-based stain is affordable and easy to find. It’s typically just labeled “wood stain,” and is what you were probably planning to use until you read this segment.
While I have plenty of oil-based stains in the house, it’s worth noting that gel stains actually do a better job of staining softwoods and plywoods. With gel stain, less stain is absorbed which results in a more even coloring.
If you’re a beginning woodworker who purchased pine or construction lumber from your local hardware store, you’re actually probably better off using gel stain.
However, gel stain is significantly more expensive than traditional wood stain, and can be difficult to apply evenly in tight areas and crevices.
Water-based stains are non-toxic, but need more coats than oil-based or gel stains to get a deep color. I use them primarily when staining underneath a water-based finish, because an oil-based wood stain underneath a water-based finish can interfere with adhesion.
As for what I usually use? I go with whatever I have in stock. I’m not a fan of buying new things, so if I have a color in inventory that works, I’m not going to fuss about if it’s oil-based, gel, or water-based.
While each stain type is ideal for certain situations, no stain is impossible to use in another manner. Gel stain is great for controlling absorption on softwoods, but there are other ways to control stain absorption if you’re using oil-based stain.
Choosing a Finish
I know this post is mostly about staining, but the appearance of your stain will look different depending on the finish you apply. I’ll keep it brief, but if you want more information, check out my full post on choosing finishes, or grab the free flowchart to make the decision for you.
Your three main choices will be oil-based polyurethane, water-based polyurethane, and shellac.
Lacquer requires expensive spraying systems, and if you’re reading this post, you probably don’t have those. Waxes aren’t very protective, and are best for paint. 100% oils are good for cutting boards, but aren’t protective enough for much else.
Oil-based polyurethane and other vaguely-named varnishes like Waterlox and Seal-A-Cell are ultra durable. If your piece will be straight up abused (like a kitchen countertop, or a kids craft table) go with one of these, no other consideration necessary.
However, oil-based poly takes forever to dry (24 hours per coat,) and releases toxic fumes, so it’s actually not my top pick for most projects.
Shellac and water-based polyurethane both dry quickly (can be recoated in under 2 hours,) and provide decent durability.
Zinsser’s Shellac Sealcoat is my go-to, simply because it can go on top of anything, while water-based polyurethane is best over water-based stain. Shellac requires a little extra work to make it matte (see the full finishing post,) but I think the ease of application is worth it.
Choosing an Application Method
If you’re using water-based polyurethane, there isn’t much to choose. Apply with a foam brush, because you want as much of the stain to soak in as possible.
However, if you’re using oil or gel stain, you have the option of rubbing the stain on with a rag, or applying with a foam brush and removing excess stain in a few minutes (see more about these two options here.)
I’m at the point where I almost always apply with rag instead of the foam brush, but often test both on my test sample (described below.) I’ve just found it’s easier to control stain absorption with the rag, since less stain is applied to the wood.
If I want a darker shade, there’s no harm in dipping the rag in the stain and applying it to the wood again.
Wood Conditioner Or Not?
Once again, I have a whole post on this here (I really like talking about wood finishing,) so I’ll keep this brief. Wood conditioner is another thing I’ll sometimes test on my test sample.
The purpose of wood conditioner is to control stain absorption on softer woods, like pine and fur. However, when applied following the directions on the can, wood conditioner also dilutes the stain, leading to a lighter application.
Note: There is some debate in the woodworking community about the right way to apply wood conditioner. Read all about that here.
Wood conditioner is one of many ways to control stain absorption, so I typically test it out, but don’t always use it, even on softwoods. Other methods, things I’m typically doing anyway like applying with a rag and sanding thoroughly, frequently make wood conditioner extraneous.
The Test Sample
The best way to test out your finishing plan is by applying the entire thing as planned on a piece of scrap wood. Ideally, that piece of scrap wood is the same wood used in your project, so you know exactly how the project will take the products.
If I’m refinishing a piece of furniture I didn’t build, or something where there really wasn’t any scrap wood, I’ll often test on an inconspicuous part of the piece. This was a hanging jewelry organizer, and I tested the stains on the back part that would be against a wall:
When I do the test, I test all the different possibilities I’m considering – application methods, wood conditioner, stains, finishes.
When I pick an option I apply it to the piece exactly as I did on the test sample. The last thing I want to is to pick a plan, and then have it look totally different once it’s on the piece.
Once you’ve decided on a plan, you can start physically preparing your wood.
How to Physically Prepare Your Wood For Staining
Step 1: Countersink and Fill All Nail Holes
If you used finishing nails on the piece, it’s worth countersinking them and covering them with wood filler.
I tested out a bunch of different wood fillers and (spoiler alert) none of them matched the wood that well, but when applied to a small dot like a finish nail, it should be almost invisible.
You can countersink nails with a nail countersink punch by placing the punch on the nail, and hammering once or twice, pushing the nail deeper in the wood. I most recently did this on my Pikler Triangle build, pictured below.
Then fill the hole with wood filler, and let it dry for 20-ish minutes before moving onto the next step.
Step 2: Sand the Wood
I debated a lot whether to make this step 1 or step 2, because ideally, you’ve sanded your wood before assembling the project. Wood is a lot easier to sand when it’s flat, especially if you have a lot of wood to remove.
But, if you’ve already assembled your piece, which is when most people start thinking about finishing, it’s a little too late for that, and it’s best to sand after wood filling so that you don’t have to re-sand the filled areas.
So here we are. I’m going to discuss this two ways: the ideal way to sand your wood, and the “drat, it’s already assembled” way to sand your wood.
Sanding Unassembled Wood
If you’re staring at a bunch of flat pieces of wood, awesome, grab some 60 grit sandpaper and a pencil. Scribble a line across the wood, and sand the wood until the line disappears.
The goal here is to eliminate any flaws or manufacturing marks. One pencil scribble can be enough, but if you can still see marks, continue sanding with 60 grit.
A nice orbital sander is great in this situation. I have a whole post on these here, but if you’re more the “just tell me what to buy” person, I recommend this cordless Dewalt sander. It’s a high-quality and well-priced tool. I have the corded version, and it’s fantastic (although if I could buy again I’d get the cordless version, which is why I recommend it to you.)
Once your scribbled line is gone and you can’t find any more marks, switch to 80 grit sandpaper, scribble a new line, and repeat the process. Now, your goal is to erase the sanding marks from the 60 grit sandpaper. Erasing the scribbled line should be enough.
Continue doing this, working your way up to 180 grit sandpaper.
Once you’ve sanded with 180 grit sandpaper, stop sanding. It is possible to sand too much! Sanding with higher grits can clog the pores of the wood, making it difficult to stain.
I’ve found 180 grit to be the perfect stopping point, where the wood is smooth and the pores are clogged enough to help even out the stain on softer woods, but still open enough to accept stain.
Sanding Assembled Projects
For many projects, it is significantly more difficult to sand the assembled piece, because fewer areas are flat and able to be sanded with the orbital sander.
If you’re feeling determined, try the above method. If not, here’s an abridged version.
Instead of starting at 60 grit, start at 120 grit. You probably won’t be able to remove the deepest marks, but you’ll remove anything super obvious, and smooth the wood to the touch.
Work your way up from 120 grit to 180 grit. Once again, stop sanding at 180 grit sandpaper.
Step 3: Prepare Exposed Edges
Edges absorb stain really differently than the rest of the wood. For a long time, I just assumed there was nothing I could do about that, and made things like this:
That’s the cat tree again, fyi. Clearly, not my best piece.
But there are a ton of things you can do to make the edges match the rest of the project. I test 5 different methods over in this post.
Some of the methods, like sanding to a higher grit and closing the wood pores, or applying a thin layer of finish before staining, require a bit of prep work before staining, hence why I’ve listed this step.
They’re all great options, but I tend to go with the one that’s the least work – sanding the edges like I sand the rest of the piece (stopping at 180 grit,) then applying the stain with a rag, even if that’s not how I did the rest of the piece.
The rag gives me enough control that I can typically make the edges match well. Plus, it doesn’t require any additional work before I start staining (other than the usual sanding in Step 2.)
Step 4: Remove Sawdust
There are a couple of official options for removing sawdust from your piece:
- Vacuum off the dust
- Wipe with an oil-free tack cloth
- Wipe with a damp cloth
All three of these methods do a great job of getting the sawdust off the wood. I don’t usually do any of them before staining.
Why? Because they’re all annoying in some way. Vacuum requires setting up the shop vac. Oil-free tack cloths are pricy. Damp cloths require I wait another 30 minutes for the wood to dry before applying the stain.
Instead, I typically just wipe the piece down with a microfiber cloth. It doesn’t remove as much sawdust as the other cloths, but honestly, that doesn’t really matter for staining.
Stain soaks into the wood. It doesn’t dry on top. And therefore, a few specks of sawdust aren’t really going to make a difference like they would if you were applying a finish.
You don’t want piles of sawdust on your piece while you stain. But a couple of specks here and there won’t hurt anything, so a microfiber cloth does a good enough job for me.
Note that before applying a topcoat, I do typically vacuum my piece. There, a speck or two does impede the finish, because the dust dries into the finish.
Step 5: Stir The Stain
Good news: wood stain can be shaken, and I’ve found that’s the most effective way to mix it thoroughly.
The pigments in both oil-based and water-based wood stains have a tendency to sink to the bottom of the can. If you don’t mix well enough, the stain will gradually get darker as you work your way through the can.
I typically just grab the stain and shake it as I walk over to the workbench. I’ve found when I’ve tried to mix it with a stir stick, I never seem to mix well enough, and there are still pigments at the bottom. Maybe I’m just bad at stirring.
Note that wood finish shouldn’t be shaken. Shaking introduces air bubbles into the product, which isn’t really a big deal with wood stain, but causes all sorts of problems for wood finish.
Gel stain does not need to be stirred.
Part 3: Less Common Ways to Prepare Wood For Staining
If you’re using a unique staining technique, there might be a few more things you need to do to prepare the wood.
For example, when you make your test sample, if you don’t like the color of the stain, you can dilute it to make it lighter, or mix it with other colors for a unique shade.
And just like you can tape walls to make interesting patterns when painting, you can do the exact same thing with stain! If going this route, and making a stain pattern using tape, be sure to use a rag and gel stain, so that the stain doesn’t bleed underneath the tape.
Finally, if you’re using a water-based stain, you have the option of dewhiskering the wood before you start. Water-based products raise the grain of the wood; dewhiskering is the process of sanding it back down.
To dewhisker wood, wipe a damp cloth on the wood. Wait for the wood to dry, then sand the wood with 180 grit sandpaper. You can also perform this process after the first coat of stain, but be careful to sand evenly so that the stain remains an even color.
Once dewhiskering has been done, it doesn’t need to be done again, no matter how many coats of water-based product you apply.