polyurethane cloudy after sanding
Kristina Davis

Is your polyurethane cloudy after sanding? Don’t worry we’ve got you covered on that.

Sadly, I’m certain that after all the energy and hard work you exerted, and presently it appears cloudy, you’re deterred. 

However, one way or the other, you are here wondering why the polyurethane got cloudy after sanding.

Well, continue reading to get the solution to your inquiry.

Yes, your polyurethane finish may be cloudy for various reasons. When this happens, ensure the final coating is dry, use mineral spirit and sandpaper to clean the old layer up, and reapply a new layer.

Polyurethane And Its Benefits?

polyurethane and benefits

Before answering the question “Why is my polyurethane cloudy?”, we will go ahead to explain what polyurethane is.

We’ll also explain how it’s beneficial and the different types of polyurethane. 

Polyurethane is an unmistakable thin fluid covering that can be sprayed on or brushed.

The benefits of it are, for the most part, defensive, to provide a protective coat.

In any case, polyurethane draws outshine in wood and bestows a brilliant tone. 

The types of polyurethane finish are listed below:

Water-Based Polyurethane Finishes

polyurethane water based

They utilize water as opposed to solvents as their base for conveying polyurethane solids. 

Water-based polyurethane can frame a hard defensive film like oil-based polyurethane, however, more coats are required.

Since it dries up rapidly, more covers can be laid quicker than oil-based items.

This polyurethane starts smooth white in its container however it dries clear. They practically have no scent.

Note: Just cleanser and water are expected to tidy up water-based polyurethane.

When Should You Use Water-Based Polyurethane?

when to use water based polyurethane

You’ll need to utilize this polyurethane, assuming you have repugnance for managing muddled, smelly solvents.

These polyurethane finishes are not difficult to use and simple to tidy up after.

If you just need a more adaptable covering, these polyurethane finishes may be ideal for you.

Indeed, one layer of the oil-based counterpart is thick. However, with the water-based item, only a couple of coats applied are almost undetectable and with basically no form.

All the same, assuming you really do need a hard look with this polyurethane finish, various coats are expected to create that outcome.

Oil-Based Polyurethane Finishes

This involves different mineral solvents and petroleum as the driving force for polyurethane solids.

Oil-based coatings are currently still being sold and utilized, not like water-based paints that used to be more easily found.

Oil-based polyurethane, accessible both in brush and spray designs, makes a hard defensive shell in fewer coatings.

This is in contrast with the water-based counterpart.

These finishes leave a marginally yellow sheen, particularly with numerous coatings, however, this might be wanted on occasion.

using oil based polyurethane

It dries gradually. Furthermore, the scent of polyurethane is pronounced and sharp.

When the item has been completely relieved, the scent will have disappeared.

It requires paint thinner or mineral spirits for clean-up. It will get smooth when it is applied on a level surface.

Tip: Spraying is the most ideal way to guarantee proficient-looking outcomes.

When Should You Use Oil-Based Polyurethane?

They give astounding resistance to scratch and abrasion.

It’s a decent decision for wood floorings or cupboards, countertops, or railings, where sturdiness is basic and important. They accomplish a rich, brilliant sparkle in a couple of coats.

However, it takes more time to dry and needs mineral spirits when getting it cleaned.

causes of a cloudy finish

What Are The Causes Of A Cloudy Polyurethane Finish?

Can your polyurethane look cloudy after sanding? Yes, it is possible that polyurethane looks cloudy after sanding.

Read on to discover the reasons why your polyurethane finish will appear cloudy after your hard work.

Development/Build Up Of Zinc Oxide

A cloudy finish can be brought about by the development of zinc oxide. Remember that polyurethane gives a glossy finish when it dries.

But to achieve a silk or matte completion, producers add zinc oxide.

Zinc oxide is used as a leavening agent, which scatters mirrored light and reduces the sparkle from the normal finish.

It can gather at the lowest part of the container.

zinc oxide powder

Thus, the answer to forestall this reason for a cloudy completion is to mix well, and afterward mix well once more.

Location Of Storage

Another explanation why you could get a cloudy completion might be because of the area of storage.

The can may have been exposed to outrageous temperature vacillations.

Maybe an exceptionally cold or a hot environment, making it possible for the outcome to be something cloudy.

Thus, the answer is to stay away from storage where outrageous cold or hot circumstances will influence.

This is because this influence will be in a not-so-great kind of way.

Polyurethane Cloudy After Sanding? – Here’s How to Fix It!

how to fix cloudy finish

I know that the question that brought you here is, “Why is my polyurethane cloudy?” Not to stress, regardless of the reason, the fix is so easy. 

Follow these means below to know how to fix a cloudy polyurethane:

The Final Coat Must Be Dry

Ensure the last coat gets dried up. Show restraint here. At times the finish will seem somewhat smooth as it gets dried up.

In the event that it’s wet, allow it to dry to ensure there is an issue requiring fixing. You have to be very patient here. 

dry final coat

You might not have a problem that needs fixing, but your patience will be worth it. Your workspace should be both perfect and void of an intensity source.

In reality, this is a word of wisdom for any getting done with a task.

Use Mineral Spirits

Splash a spotless fabric or finishing wipe with spirits. Then, wipe the impacted region down.

First, permit it to get dried up, drench the fabric or wipe once more and rehash this cycle. Do this until you get down to that stain or mess.

Tip: Make sure to allow it to get totally dried up before proceeding to the next step.

Make Use Of The Sandpaper

use a sandpaper

Daintily sand the region with fine-coarseness paper. 220-coarseness ought to be great until the region is no longer cloudy and the polyurethane finish has all been eliminated.

A ball of fine wool might likewise be utilized, too. Sand the surface.

Note: However, 220-coarseness sandpaper will turn out only great for you. Sand the surface.

Clean Up

Ensure every dusty thing is taken out and the region is currently completely spotless. A marginally soggy material can assist.

Any lingering residue will be obvious through the wood finish, so make sure everywhere is cleaned up.

Make Sure To Mix The Polyurethane

Mix the polyurethane properly, and afterward, mix it once more. Or on the other hand, perhaps a new one might even be better.

apply a new layer

Apply New Layer

With a brush, lay down new layers of wood finish and follow through with the guidelines on the container.

Permit sufficient time for the coats to dry before applying the following. Make certain to mix a long time before applying a new coat.

If the whole surface of the new table top that you constructed appears to be cloudy, then obviously, the whole surface should be handled in this particular manner above. 

Allow it to get dried up, utilize mineral spirits, and use it to take away the polyurethane, including the stain.

Then sand the entire surface of your furniture, clean it completely, and apply the finish coats again.


Polyurethane finish provides a protective coat and gives off a brilliant tone.

However, you might have used the polyurethane finish before and you discover a cloudy appearance. 

And you probably found yourself wondering, why my polyurethane is cloudy after sanding.

Don’t stress at all, the process of fixing cloudiness after sanding has been explicitly explained in this article. 

This article also includes additional information on what polyurethane finish is and the different types of polyurethane. We hope this article has been helpful.