A polyurethane finish is the most popular finish for protecting wooden furniture from scratches and general wear and tear. It also makes it water-resistant. But you may not like the glossy finish you get, or there could be imperfections as it dries and cures. Polishing your polyurethane finish can remove imperfections and help you get the look that you want. But can you polish polyurethane with steel wool?
Yes, you can polish polyurethane with steel wool, it is one of the best ways to polish polyurethane. On its own, it will dull the surface, or you can use paste wax to get a nice polished finish. However, it is important to use a fine 0000 steel wool to avoid scratches.
I will explain how to polish your polyurethane with steel wool, and outline some of the big mistakes to avoid.
Can Steel Wool Scratch Polyurethane?
Yes, steel wool can scratch polyurethane if you’re not careful. When used correctly, it can give you a nice finish but there are some common mistakes that can easily ruin it.
Firstly, you need to make sure that the polyurethane is properly dried and cured before you use the steel wool. If it is still slightly wet, the steel wool will leave behind big scratches. It can also lift the finish and cause it to peel, so you will have to strip it and start all over again if that happens.
Using the wrong grit steel wool is a common mistake too. A coarse steel wool will scratch the surface too much and ruin the finish. You need to use a very fine wool that will smooth the surface gently without taking big chunks out of it.
Not cleaning the surface properly before using the steel wool can potentially cause damage too. Small pieces of dirt, dust, and grime get rubbed into the surface and leave big scratches behind. To avoid this, make sure you wipe the surface down thoroughly before you rub it down with steel wool.
It’s important to use the right technique too. For the best results, you need to lubricate the steel wool and the polyurethane then use a circular motion to polish out the surface. You can find my step-by-step guide below with more detail.
How Long Should You Wait to Polish Polyurethane?
It’s important that you let your polyurethane dry properly before you polish it with steel wool. If it is still slightly wet, it will scratch and drag, ruining your fresh finish. You don’t need to wait for it to fully cure, however, but it does need to be nice and dry.
Just check the guidelines on the tin of polyurethane you have used to see what the drying times are. Usually, polyurethane needs about 24 hours to dry properly. Depending on your workspace, if humidity is high and temperatures are high, you may want to leave it 48 hours just to be sure. I often let it dry overnight in optimal conditions and buffing works great for me.
Before you start with the steel wool, check whether the polyurethane finish is dry or not. There are a few ways to do this but we do not want to damage the finish, first I just give it time because I do not want to touch it too soon. Then I will rub my hand over the surface to see if it feels slightly soft and even sticky. If it feels hard and durable its ready for buffing!
What Steel Wool is Best for Polishing Polyurethane?
Steel wool comes in different grits, just like sandpaper, but the grading system is different. When polishing polyurethane, you need a very fine steel wool so it dulls the surface and gives a satin finish without leaving large, visible scratches behind. There are 8 different grades of steel wool:
- 4 – Extra coarse
- 3 – Coarse
- 2 – Medium/coarse
- 1 – Medium
- 0 – Medium/fine
- 00- Fine
- 000 – Extra fine
- 0000 – Finest
For polishing polyurethane, you need 0000 steel wool, the finest option. This is an incredibly fine wool that can be used for polishing and buffing furniture. Using any other steel wool will likely leave scratches on your finish.
Do You Use Paste Wax to Polish Polyurethane?
Yes, using paste wax and steel wool is a common technique for polishing polyurethane. It gives you an excellent finish without any scratches and also gives the surface better protection. You don’t need a lot of paste wax when polishing, just add a tiny amount (pea size) on the poly with a rag, spread it on the surface and then you can use the steel wool. You can then buff it out with a clean lint-free rag.
You can polish again after 8 hours, or the following day, just do the exact same process if you want to polish it better.
It’ll be far easier to get a good finish if you use high quality paste wax. Howard Citrus Shield Paste Wax is an excellent option for use with polyurethane, especially on wooden furniture. It’s a natural paste wax made with orange oil, beeswax, and carnauba wax that gives you a strong protective finish. The nice citrus smell is an added bonus too.
I have used Minwax Finishing Paste wax too numerous times and it is a great wax to have on hand.
How to Use Steel Wool to Polish Polyurethane Finish (Step-by-Step)
1. Clean the surface
Start by cleaning the polyurethane surface to remove any dirt, dust, or debris. You can use a damp cloth or a mild cleaner to remove any grime on the surface. This is such an important step because any dirt will cause an uneven layer of polishing, the pressure of the dirt will leave scratches on the polyurethane ruining the finish.
Also, like I mentioned already you need to make sure the surface is completely dry before you start polishing!
2. Apply Your Paste Wax
When using finishing paste wax to polish your polyurethane furniture, apply a pea sized amount to the surface and spread it evenly with the cloth. Use just enough polish to cover the surface, a little goes a long way, but avoid using so much that it becomes too difficult to work with. You may need multiple layers, but it’s vital that you use a thin layer if you want a good polished finish.
3. Polish with Steel Wool
Now you are ready to start polishing with your 0000 steel wool. Take a piece of steel wool and gently rub it over the surface in a circular motion. Start with light pressure and gradually increase it until you get the desired level of shine. Be sure to use a consistent pressure and movement to achieve a uniform shine.
This circular motion helps polish by removing flaws in the surface, such as bubbles, dust marks, and related blemishes.
4. Clean Up the Excess Wax
Although we didn’t use a lot of paste wax, steel wool isn’t designed to polish and clean the wax off. It will polish and make it smooth as it acts like sandpaper in a way. After using the steel wool to polish we then use a lint-free rag to wipe the remaining wax on the surface.
I start by wiping in a circular motion, then finish off by rubbing the same way as the wood grain. This is basically a final clean and polish, it will look super smooth when finished. Now avoid touching and do not allow dust to fall on the drying wax.
5. Check the Finish
Examine the surface to ensure that the shine is consistent and there are no streaks or smudges. Going with the grain with your lint-free rag/cloth is your last pass, apply some pressure and it should look super smooth.
If there are any imperfections, go back over the area with steel wool if needed and polish until the surface has no bumps or specs. Then with the clean rag removing excess wax and finishing it off smooth to eventually dry to its finished state.
Is the Process Different When Polishing Water-Based vs Oil-Based Polyurethane?
You can use the same process when polishing water-based and oil-based polyurethane. However, there are differences between the finishes, so you may need to be more cautious with water-based finishes. Generally, an oil-based polyurethane gives you a much more durable finish that is less prone to scratching.
That means that it’s harder to remove imperfections and it will probably take longer for the steel wool to give you a smooth finish. Water-based polyurethane, on the other hand, has a slightly softer finish so it will polish faster. But, you need to be gentle with the steel wool to avoid scratching up the surface.
Can Steel Wool Rust When Used on Water-Based Polyurethane?
Some people say rust is a potential problem when polishing water-based polyurethane. After you have polished the surface with steel wool, it can leave tiny metal fibers behind. If they get trapped in the polyurethane finish, they can rust over time and leave brown spots.
You definitely want to avoid this, make sure you don’t skip the cleaning step after you have polished. Use the lint-free rag to give it a thorough wipe down and final polish to remove any steel wool fibers.
Can You Just Use Sandpaper to Polish Polyurethane?
You can polish polyurethane with sand paper but it is not always the best option. Sandpaper must be evenly pressured when used or it will more than likely cause scratches and scuff marks.
If you are to use sandpaper on your final coat you can use a super high grit to avoid damages. I would use a 400 grit then a 600 grit sand paper. This should remove all specs, bubbles, and dust marks. You will likely need to add paste wax on the surface to make it look fresh and finished as the sandpaper can make it look cloudy. You can even use a 1500 grit sandpaper to polish in the paste wax.
You can use a rag to clean the wax once finished, just how I explained it above in step 4.
Although this sandpaper method works well, a 0000 steel wool gives you better results and you’re less likely to get scratches.
Do You Have to Polish Polyurethane?
No, you don’t have to polish polyurethane if you don’t want to. However, you usually get a very glossy finish, which may not be what you want. By polishing it with steel wool, you can take off some of the shine. You can also remove any imperfections and get a smooth surface.
Polishing your polyurethane gives you more control over the end result, but if you are happy with the finish after the final coat has dried, you can leave it.
I have done this many times and have had success spraying polyurethane and it comes out very smooth without the need for polishing.