Can You Put Polyurethane Over Danish Oil?

You’ve just finished your woodworking project, and you have given it a nice-looking Danish oil finish. However, you are in a dilemma about what to do next and whether you can put polyurethane over Danish oil.

The reality is, you’ve heard it is important to seal your workpiece to achieve a glossy finish and make it durable. But you’re asking, can you put polyurethane over Danish oil?

Well, stick around because I will be answering the question; can you put polyurethane over Danish oil?

Let’s jump in;

Can You Put Polyurethane Over Danish Oil?

Both oil-based and water-based polyurethane have no bad effects when put over Danish oil. It adheres well with Danish oil but only when you have given the preceding coat enough time (up to 48 hours) to dry.

How Long Does Danish Oil Take To Dry and Cure?

One main advantage of danish oil is its drying time. Danish oil will require about 6 hours to dry and up to 24 hours to cure. 

If you apply multiple coats on your workpiece, the Danish oil finish will take several days, up to one week, for the coat to cure.

To add, it might take more than one week if you are working in cool and/or damp conditions.

While applying Danish oil when working on one of my projects, I noticed pure oil alone doesn’t cure into a hard resin. If you use natural oil only to your wood surface, it won’t form a solid film.

This is because curing involves chemical reactions that convert the liquid solution into a hard solid. This is why Danish Oil finishes are mixed with linseed or tung oil plus varnish to cure into a hard film.

Related: Can you put polyurethane over tung oil?

Does Danish Oil Even Need a Top Coat?

There’re woodwork projects that won’t need a top coat when you finish them with Danish oil. For example, wooden furniture that is used frequently can become dull and may wear fast. 

Adding a topcoat (extra hard-wearing) is necessary. However, if you have a workpiece you won’t handle all time, e.g., wooden clocks, there’s no need for a topcoat.

With that in mind, my take is, Danish oil doesn’t need a topcoat. Many over-the-counter Danish oils are designed to be an all-in-one finish solution – they don’t require an additional protective coat.

Should I Use Oil or a Water-Based Polyurethane on Danish Oil?

So you’re torn between water or oil-based polyurethane, then let me take the burden off your shoulders. If I were for pure looks over substance, I would go for oil-based polyurethane.

Even though you can use water-based poly on Danish oil, oil-based poly stands out. However, if I want to save time working on large projects, I may go for water-based polyurethane as it dries faster.

Still unsure about which one is best, let’s take a quick run through the pros and cons of each one:

1. Oil-Based Polyurethane

PROS

It’s a rich finish that gives natural wood a rustic shine.
It’s less expensive compared to water-based polyurethane.
Less touch-up work is needed once the job is done.

CON

It takes longer to dry than water-based (4 times longer).
It darkens into an ever-deepening amber tone when it ages.
It produces more fumes than water-based polyurethane.

2. Water-Based Polyurethane

PROS

It dries faster than its oil-based counterpart.
You can apply multiple coats within one day as it dries faster.
Durable because it uses an acrylic resin base, unlike oil-based, which uses an oil base.

CON

It looks duller.
It often saps the wood of its vibrancy.
It’s more expensive than oil-based polyurethane.
It requires more maintenance than oil-based poly.
It is not waterproof (Is polyurethane water resistant?)

How to Apply Polyurethane over Danish Oil 

Let’s have a look at how you can apply polyurethane over Danish oil.

Materials and Tools Needed

Here are the materials and tools you’ll need to apply polyurethane over danish:

• 120-, 180-, 220-, grit sandpaper.
• 80-grit sandpaper (for refinishing jobs).
• Oil- or water-based polyurethane (Can you put polyurethane over old polyurethane? Find out in our article. )
• Quality brush (natural bristle brush and a nylon bristle brush for oil-based polyurethane and water-based polyurethane respectively)
• Automotive rubbing compound
• Automotive polishing compound
• A tack cloth or dry lint-free rags
• Vacuum cleaner
• Mineral spirits -for thinning oil-based polyurethane)
• Distilled water -for thinning water-based polyurethane)

Steps-By-Step Procedure for Applying Polyurethane Over Danish Oil

Step 1: Prepare the Work Area

Use a vacuum cleaner to ensure your work area is star-free a few hours before starting the project. Also, be sure to work in a well-ventilated workshop, under optimum light to see imperfections.

Step 2: Prepare the Wood Surface

Just like in putting polyurethane over resin, wear a nose mask and sand the Danish oil coat using  80- or 100-grits sandpaper, then smoothen it with 220-grit sandpaper. Use a dampen tack cloth to clean the wood surface.

Step 3: Apply Danish Oil

Reapply Danish oil and allow about 4-6 hours drying time. 

Step 4: Apply Polyurethane Over Danish Oil

In this step, you can use the wipe-on poly or brush-on poly, or the spray-on technique to apply poly over Danish oil. The result will be similar. I will be using the brush method for flat surfaces.

However, use the wipe-on method for contoured surfaces and the spray-on method for hard-to-reach surfaces.

• Step I: Dip about one-inch of your brush into the poly. 
• Step II: Apply the poly by following the direction of the grain (even, long strokes are recommended). 
• Step III: Ensure there’re no drips or gaps on your workpiece and allow about 24 hours for it to dry. 

See also: Making wipe on poly instructions.

Step 5: Wet Sanding the First Layer

Use fine-grit sandpaper (wet it to avoid damaging the finish of the previous polyurethane) for sanding the first coat of the poly.

Step 6: Thin Your Polyurethane

Thin your poly by mixing two parts of oil-based poly with one part mineral spirits. Use distilled water-based polyurethane.

Step 7: Apply the Second and Third Coat

Apply the second coat of poly and allow 24 hours drying time before sanding and applying the third and fourth coats.

Recommended read: Can you use oil-based polyurethane over water-based stain?

How Can You Tell if Polyurethane Is Oil or Water Based?

Looking at the label of the polyurethane container is the easiest way to tell oil-based from water-based.

Sounds easy, right?

But is it true?

Well, there might be an error during labeling, so the best way to differentiate the two is to take a look inside. Usually, water-based poly is milky when inside the can. However, its brushes are clear.

Related post: Can I apply polyurethane over chalk paint?

How Many Coats of Water Based Polyurethane Should I Use?

If you’re after basic protection, using a minimum of 3 to 4 coats of water-based polyurethane will be a good start. However, you can add more coats if you aren’t on a tight budget.

Again, it is wise to do touch-up coats after a few years to have an ever-good-looking finish on your wood surfaces.

FAQs

1. What Can I Put On Top of Danish Oil?

Danish oil doesn’t build like a film finish, so you can put polyurethane over it. You can also use lacquer if you’re working on surfaces that may be exposed to liquids or abrasion.

Reapplying oil with and some wet sanding will restore the original luster if it suffers damage.

2. How Long Should Danish Oil Dry Before Polyurethane?

Danish oil finished surfaces may take up to 8-10 hours before use. However, if polyurethane is to be put over it, allow 72 hours before application.

3. Can You Seal Danish Oil?

Yes, you can. Danish oil doesn’t require sealing, but to give it extra hardness and durability, you can use any oil-based varnish, either resin or polyurethane, to seal it.

Read also: Can you paint on trex boards?

4. Can You Put Water-Based Polyurethane Over Oil?

Yes, you can put a water-based polyurethane coat over Danish Oil. It will adhere to the finish as long as the Danish oil coat is fully cured.

5. Can I Spray Polyurethane Over Danish Oil Finish?

Yes, you can spray poly over danish oil rather than brushing or wiping-on method. No matter the method you use, poly will bond fine with the oil.

6. Can you polyurethane over polycrylic?

Yes, you can polyurethane over polycrylic. However, are some important considerations to keep in mind. Before doing so, ensure that the polycrylic is well cured, which takes about 30 days. Additionally, lightly sand the surface to promote adhesion. Putting polyurethane over polycrylic can create a more durable and protective finish.

Can You Put Polyurethane Over Danish Oil?

As you’ve read, it is good practice to put polyurethane over Danish oil despite standing on its own.

Polyurethane will make your finish stand out, plus it is durable. It will take you several years before you do maintenance on your project.

To add, polyurethane is tear, abrasion, impact, mold, mildew & fungus resistant that’s why I recommend applying it over Danish oil.

Did I leave out something you wanted to know? Shoot us a comment, and we’ll work towards adding it to this article.

What next? Read our article on how to apply wipe on polyurethane and leave us a comment if you find the information helpful or have any questions!