Because of its durability, polyurethane is mainly applied as a top coat. Poly sealer is impenetrable once it has hardened, cured, and dried on wood furniture.
However, what should you do if you realize that your polyurethane coat is starting to show signs of wear? Is there anything you can do to remove the unattractive dust nibs from that polyurethane finish?
After scuff sanding between layers of polyurethane, clean the surface with mineral spirits to remove dust, dirt, grit, and grime from the surface.
To remove dust nibs from cured polyurethane, sand off the top layer of polyurethane.
What is the propensity of polyurethane to attract dust?
Polyurethane is no more or less dust-attracting than any other surface treatment. Although polyurethane takes a long time to cure, the finish can appear as a dust magnet. If you wait long enough, dust will settle on anything.
Similarly, applying a fast-drying polyurethane to a surface can take a few minutes to a few hours to cure and harden. Before polyurethane can dry, the dust will have had plenty of opportunities to settle.
Make each application thin, or use a wipe-on poly, to speed up poly’s drying time. Wipe-on poly dries in only two to three hours. This can go a long way to help keep dust from settling on the finish.
How can you prevent dust nibs?
Due to its smooth, plastic-like surface, applying successive coats on dry polyurethane cannot be easy. That dry polyurethane undercoat has to be scuffed up a bit.
Using high-grit sandpaper, softly sand the polyurethane between layers, ideally 220 grit. Use a sanding block to wrap the sandpaper around.
The next step is to sand the surface with long, gentle strokes. Repeat going in the same direction with each stroke.
Do not scuff the polyurethane with your fingernails. Scuffing creates a little grip by roughening up the surface, and that is precisely what we want. However, you don’t want to leave behind a trail of dust and grit.
To remove all of those sanding particles, you’ll need to do more than blow them away.
You’ll have to wipe the specks away with mineral spirits to ensure you get rid of them completely. Because it has virtually no smell, you can use it in your workshop even if you’re inside.
Clean wood after sanding polyurethane
If you have mineral spirits on hand, you can use them to remove off the scuffed polyurethane finish.
As a reminder, only lint-free cloth should be used for cleaning.
If you wipe with a microfiber or cotton cloth, lint will build up on the surface.
Additionally, your dust nib issue will be replaced by one with lint particles. Utilize this kind of cloth, such as those made for wood finishing, to ensure a clean surface.
How do you get rid of polyurethane dust nibs that have been set?
Sanding is the only alternative you have in this situation. To eliminate the polyurethane’s cured coat, you need sandpaper with a lower grit, 220 or less, because the cured poly is considerably more difficult to remove than dry poly.
It’s unnecessary to sand back to bare wood after you’ve removed the top coat. Mineral spirits can then be used to clean the surface. After that, reapply the final coat of topcoat. Your dust nib problem should be resolved with a new final coat.
How to dry the last layer of polyurethane?
A vacuum cleaner is the only way to get rid of the dust on the wood.
If you’re working on a floor, you must hover over every square inch of the area, especially in the corners. A few dust specks may remain after you vacuum the floor.
Wipe the floor with mineral spirits or water, whichever type of polyurethane you have, to get rid of the stains.
Take a break and allow the area to dry for a few minutes. Even if you use a small amount of liquid, the process should be quick.
After it has evaporated, check the surface to determine if any flaws remain.
Use a sanding block to apply the 600-grit paper to the area where the finish has dents or dust nibs.
When you do this, you don’t want to mess with the smooth parts of the finish.
A tack cloth can be used to clean the surface of the furniture. Verify that the flaws have been removed.
Meticulous checking will save time and effort to avoid repeating the same mistake.
How to wet sand polyurethane coat?
Add about a quarter of water or mineral spirits to the cup.
Mineral spirits should only be used for oil-based products. Soak a sanding tool in water until it’s nearly completely submerged.
Alternatively, you can soak it for 24 hours, in which case you will not need to add water to the polyurethane’s surface.
Drench the area with water as you begin to use the wet or dry sandpaper. It is best to use a circular motion to sand away the flaws.
The water will keep the polyurethane from clouding, and the sandpaper’s scratch marks mild. To keep track of your work, wipe the surface with a clean towel every time you see it.
Please don’t use the same cloths again when cleaning; repeat the step afterward, and before putting any sealant on the surface, give it 24 hours to cure.
What if you don’t sand the final coat of polyurethane?
If the final polyurethane layer is not sanded, nothing happens. Because of this, you only file the last coat if there are minor issues.
To avoid bubbles, unevenness of surface, and dust nibs, apply another polyurethane layer after the first one has dried and then sand the surface.
Of course, this situation occurs if you accumulate more experience. Less mistake means you do not work more on focusing only on the core project.
Avoiding the Dust Nibs
Clean dust sooner than wait until it has accumulated on everything. Use a dust-collection system to ensure you catch dust before it spreads across the room.
At least one hour before applying a finish, turn off air filtration equipment so that airborne dust can be caught.
Vacuum the day thoroughly before your final session to remove any lingering dust. Wipe down your work surface and any nearby spots using a moist rag to remove dust that has remained after the cleaning process has been completed.
