can you stain over polyurethane

Can You Stain Over Polyurethane?

In Tips by Jamie P.

You might be wondering if you could just apply stain over polyurethane, you don’t want to deal with all the stripping and sanding required to get down to the wood. Whether you were to strip or sand furniture, it is going to make a mess, so there is a trick that can save you time and the hassle. So can you stain over polyurethane?

Yes, you can stain over polyurethane but only with gel stain. Gel stain will layer over the polyurethane finish, making the surface appear stained. If you were to use a regular wood stain, it wouldn’t be able to penetrate through the polyurethane and the stain would just wipe off. 

What to Consider When Staining Over Polyurethane?

There are a few things to consider when staining over a finished surface, such as the wood grain, the adherence, and the stain color.

Wood Grain

I know for me personally, when I stain wood I prefer to remove all the old finish off so I can get down to the bare wood. This means when I apply the new stain color it will make the wood grain pop, and if you watch my videos on YouTube you know that is my favorite part about staining.

When applying stain over polyurethane, you won’t see this new grain pattern, instead, it will just look the same as it does, of course, this depends on the stain color you choose too. The reason you won’t have a new popping wood grain is that the polyurethane is acting as a sealer for the wood, this prevents any stain product from penetrating into the wooden surface. This is why regular wood stain will not work over polyurethane, because the stain is trying to penetrate while the polyurethane is preventing it from doing so. Just think, you use polyurethane to protect the surface from liquids damaging it.

If you are interested in learning more about removing an old finish off of furniture for staining, you can read our full guide on How to Stain Furniture by clicking here. This is considered the most durable and professional way of staining a piece of furniture, but not the only way.

Stain Adherence

Just like paint, we need to consider how the stain will adhere to the surface. When applying gel stain over polyurethane, we are adding a thin layer of gel over the poly, this means it needs to adhere to the polyurethane surface. I compare it to painting furniture, I will follow the same steps:

  1. Degrease cleaning
  2. Light Sanding with 220 Grit Sandpaper
  3. Remove Sanding Dust
  4. Apply Gel Stain

Light sanding is really a game-changer when it comes to applying gel stains on non-wood surfaces. I follow similar steps when staining laminate furniture, just having that light sanding will triple your stain adherence making it last longer and look better.

Stain Color

Ok, I know you probably didn’t even think about the color of stain you are using but this is very important. Since you plan to skip stripping and sanding away the old poly your piece is probably stained a certain color already. The current color sort of determines what color you can stain it. If your piece is a super dark-looking wood, you can’t really apply a lighter stain color expecting it to look that color afterward.

If I am going to stain over polyurethane, I try to pick a color similar to what the wood looks like, going darker is always the best option. Older pieces may have scratches or gouges in the wood, if you go dark they fill in nicely and they match up. If you go light on a darker piece, these areas look lighter and do not match up nicely.

I will say testing will help you understand what it would look like after staining, maybe you like the mismatched look, but without getting down to bare wood you are going to have limited options when it comes to colors.

7 Steps How to Stain Over Polyurethane

It is now time to explain the process of how I would go about staining over a polyurethane surface. By following these 7 steps you can easily accomplish staining over polyurethane using a gel stain. These steps ensure the best possible quality

1. Degrease Cleaning

degreasing furniture for paint

Cleaning is important, more important than most people think. If you want to stain a polyurethane surface it must be free from grease and grime or your gel stain is not going to look good or last long. When I clean furniture for painting and staining I follow a similar process. I either use warm water and dish soap, or Krud Kutter.

I spray the full surface with my degreasing product Krud Cutter, then wipe it all up using a clean rag. Once the surface is cleaned with it is best to clean off the remaining cleaning product with warm water and a cloth. This is best to remove any remaining cleaning product because you don’t want that under your stain either. I then use a completely dry lint-free rag/cloth to dry the piece as best as I can. At this point I let the piece sit to air dry fully before getting things started.

2. Light Scuff Sanding

I already mentioned this briefly, but doing a light scuff sand with 220 grit sandpaper or a sanding sponge will make your gel stain adhere much better. Nothing adheres well to a glossy surface, and most of the time polyurethane is pretty glossy, so scuff sanding helps a lot.

If sanding by hand, using a sanding sponge will prevent sanding marks and scratches, I recommend using one like the 3M Pro Grade Precision Ultra Flexible Block Sanding Sponge. They last long and do a good job scuffing the surface.

3. Clean Dust

Since we did some light sanding there will be some sanding dust. This is important to clean up before we apply our gel stain, or the stain is going to look dirty. The best cleaning method at this time in the process is to use a tack cloth. A tack cloth is like a sticky rag that picks up dust on the surface, this is exactly what you need after scuff sanding. I wipe everywhere that will be stained and then it should be dust-free for stain.

Sometimes I use a damp rag, it works pretty similarly to a tack cloth because it will grab the dust on the surface quite well.

4. Apply Gel Stain

staining over poly

When applying gel stain you use a clean lint-free rag or a foam brush, how you apply it doesn’t matter as much as wiping it off. Just make sure that when you are applying to use a clean applicator, dust or old paint can show causing texture and visible problems that you really want to avoid.

Here is how I apply gel stain in 3 steps:

  1. Grab a clean lint-free rag and scoop a generous amount of gel stain out of the can.
  2. Take the gel rag and apply it on the surface you are staining, begin rubbing it back and fourth or in a circular motion until the full surface has been covered with gel stain.
  3. Now let the stain sit for a couple of minutes before wiping off.

As you can tell, the process is quite simple and I think subjective. You can pretty much apply gel stain however youa re comfortable doing so. Just keep it clean and you shouldnt have issues, and don’t apply too much because it will just be a waste of product. Gel stain only works in thin amounts anyways,or it won’t properly dry for a long time.

5. Wipe Off Gel Stain

Now onto the most important part of applying gel stain, especially when applying over a finished surface, the wiping process. The reason this step is so important is that the way you wipe off the stain is how it will look when finished. Since we are staining a finished polyurethaned surface we should follow the grain as we wipe. This is a good idea anyway, but when you apply on bare wood the stain absorbs and automatically follows the grain, this is not the case when applying over a finished surface. The way you wipe may leave subtle lines, you should match them to the grain to look as natural as possible.

The way I wipe gel stain is to grab a clean lint-free rag, but make sure it is a smooth material because I used a microfibre cloth once and it leaves the little lines which is super annoying to look at. So, grab a clean rag, the best is an old t-shirt, and fold it up into a firm mini square or rectangle, then begin wiping the thick gel off in the direction of the grain. Start by lightly wiping, the more pressure the more gel stain comes off the surface. You want to leave enough gel stain to tint the surface to your desired outcome.

But DO NOT leave thick puddles of gel stain on the surface or it won’t properly dry. I did this once on a laminate surface, and after 2 days or so it finally dried, not fun haha. You can stain laminate, but by following these steps, do a light layer of gel stain and you shouldn’t have issues.

6. Wait Until the Gel Stain Dries

Ok, you made it this far without going crazy. Alright, maybe you did lose your mind a few times, but trust me that’s how this hobby works. You need to fail and learn from your mistaks to slowly become better and better.

Anyway, at this point you have applied the gel stain to how you want it to look, if you are having issues here is what you can do:

  • If using an oil-based gel stain, use mineral spirits and a rag to remove the gel stain to restart.
  • If using water-based gel stain, use water and a rag to wipe away the gel stain to restart.

Now, do you feel better? You can make mistakes and easily fix them, that is a plus in this process of staining.

After finally getting to the look that makes you smile, let it sit for at least 2-3 hours, sometimes if humid I let the gel stain sit overnight to get dry to touch. If you apply a topcoat over the wet surface, it will take days for things to cure and harden up to a durable surface.

7. Apply Protection

spraying poly over gel stain

What do I mean protection? I mean applying a clear topcoat that will protect the gel stain we just added to the surface. Gel stain is not durable on its own so this means we need to add something to make it durable for regular use. There are a few options to choose from:

I have used each before, however, I often spray water-based poly through my sprayer, which creates a very smooth durable surface. I know not everyone has a spray gun so I will explain a few methods below. I typically don’t use oil-based poly because water-based is much easier to clean, anyway here are some methods to protect the gel stained surface.

Applying Water-based Polyurethane – There are multiple ways to apply WB Poly, the easiest way and the beginner-friendly way is using a foam applicator or foam brush. It may leave tiny streaks but it is an easy option. Just dip your foam applicator into the poly and begin wiping straight lines with the grain, but don’t wipe if the gel stain is wet or this will get messy. Simply wipe/brush the entire stained surface in even consistent straight lines until fully covered.

Another option, and my recommended option, is to spray the poly on the surface. The reason spraying is a good idea is because it doesn’t leave brush lines and streaks, and you prevent yourself from scratching or messing up the gel stain surface. You can spray with an aerosol can or an HVLP spray gun, like my Wagner or HomeRight.

Lacquer and Shellac – I like lacquer, but it stinks and you don’t want to breathe these fumes in so only use it if you have the proper gear and ventilation. I would only spray it with a can, but with the right equipment, you can use a spray gun too. Lacquer will provide a very durable surface, you will need to apply at least 4 coats for good protection. Shellac can be used similar to lacquer, get a spray can of it, which is usually more expensive, and spray 4+ coats for durability.