June 2, 2021

How Many Coats of Polyurethane? The Only Answer You Need

How many coats of Polyurethane should I use? I hear that all of the time. As part of learning how to refinish furniture, many people have the misconception that they will have to apply specific coats of Polyurethane to finish off the wood. This is not quite the case, and it is possible to use Polyurethane just once, and then the work needs to be finished with a varnish. Let’s look at this in detail.

How many coats of polyurethane for wood floors?

Wood floors need at least three layers of polyurethane. Two or fewer coats expose the wood floor to wear since there is more traffic on floors than on cabinets that you use here and there. Since there are chances of having moisture daily on the wooden floors, three coats give better protection to the floor. 

However, the number of coats depends on the type of product you are using. Oil-based products require two coats as a minimum and three as a maximum. Four layers of water-based polyurethane are also allowed. Since more layers mean an added layer of protection, I advise you to run as many layers as you want. More layers ensure durability. 

How many coats of polyurethane for wood cabinets?

All wood requires two or more coats. The first coat is a primer and sealer and the second coat is a finish. A third layer is water-based polyurethane. Colored polyurethane needs several coats to reach the color tone of your choice on the wood cabinets. I advise you to make tests on a test material before you make your coats. 

I recommend the use of high gloss on cabinets. Low-gloss polyurethane is less durable on cabinets than high-gloss. Wood cabinets are exposed to heat and humidity hence the need for a perfect coat. The process requires minimal tools and preparation. 

How many coats of polyurethane for wood tables?

Varnish Gloss Wipe-On Polyurethane Solvent Based Quart

Unlike cabinets that you open occasionally, the table is for daily use. That is why you need three coats as the minimum for a perfect table finish. However, you are not limited to three coats. More coats give extra layers for a glossy and shiny finish. 

The first step involves spraying the coat finish. Spray it in the same direction, and each layer has to dry for 2 to 3 hours. Brush the coat finish and leave each coat for a minimum of two hours. The final coat has to rest for 24 hours. 

How many coats of polyurethane for wood table tops?

Three coats of polyurethane are for wood table tops. Polyurethane seals and protects the wood tabletop. It does not allow water and oil to penetrate the wood. The first coat involves dripping the bristles, tipping off drips, and painting along the grain. 

Repeat the process of applying the coat along the grain till you are satisfied. Do not touch the top till it is dry, and leave it to dry for 24 hours.

Sanding

There are pros to sanding when coating surfaces with polyurethane. The sanding process involves removing dirt, hair, and grit from the surface in preparation for the next coat or finish. Sanding is not time-consuming since you are allowed to run it while the other coat is drying. 

Sanding makes a rough surface that makes boning the next layer easy. It ensures smoothness and consists of multiple methods. Oil-based layers need steel wool, whereas an abrasive pad is for water-based polyurethane. 

How to apply polyurethane

  • Gather your tools and materials. The tools required are a sanding block and a shop vacuum. The materials include automotive polishing compound and rubbing compound, sandpaper, tack cloth, mineral spirits, and lint-free cloth. 
  • Sand the surface using sandpaper.
  • Remove the dust from the wood surface using a vacuum attached with a brush.
  • Wipe the surface with a tack cloth.
  • Seal the surface with polyurethane and mineral spirits.
  • Brush the sealer with a brush.
  • Use the brush to catch drips and smooth the surface.
  • Apply the first coat of polyurethane. 
  • Remove the bumps.
  • Wet-sand the first coat. 
  • Apply the second coat.
  • For several coats, wet sand and apply the coat.

Polish the surface 

Use fine-grit sandpaper to sand down the brush marks. Apply even pressure onto the area as you are sanding. Take a soft cloth and brush the sanded area. That has to remove traces of dirt and grit. Skipping the brushing process leads to material getting under your finish, and that ruins your project. It will not be accurate and beautiful as intended. 

Applying the second coat and third coat

Waterbase Polyurethane Satin Quart

Applying the second and third coat requires you to repeat the process followed for the first coat. Shave off the bumps on the first coating by sanding or using a sharp razor blade. Wet-sand the first coat and apply another coat. 

Are two coats of polyurethane enough?

Two coats of polyurethane are enough for surfaces not exposed to hard-wearing. Wood surfaces that are occasionally used use two coats of polyurethane. Floors should have more than three layers since they are used daily.

Can you put a second coat of polyurethane without sanding?

Applying a second coat of polyurethane without sanding brings negative results as much as you may use water-based polyurethane that is more self-leveling, sand before you apply it. Failure to sand brings dirt and grit under the coat. That affects the coating process as you will not have a perfect finish. 

The finish will not be smooth and flawless. That is unattractive, and it does not make the coat last longer. Sanding prevents drips or runs. You may replace sanding with a sharp razor blade. However, you still have to sand off the surface for a fresh coat. 

How long should I wait between coats of polyurethane?

You have to wait for 24 hours as you wait for the first coating to dry. Thin your formula using paint thinner. That makes the drying process faster. As soon as the first coat dries, sand the first coat using fine-grit sandpaper. After sanding and cleaning the first layer, apply the second coating. 

How to dry polyurethane faster?

Thin your polyurethane formula using paint-thinner thinning. As you apply polyurethane, the brush has to be along the grain. Stretch the polyurethane into a thin coat. It has to be thin. 

The second layer has to dry for 24 to 48 hours before sanding. After that, you are allowed to add another layer if you want. The same way you apply layers of nail polish is the same way you have to follow when applying polyurethane.

What happens if you don’t sand between coats of polyurethane?

If you do not want sand between coats of polyurethane, dirt becomes part of the surface. Bumps are a result of not sanding. The wood coat does not level. That makes flaws on the surface, and it might even disturb the whole process. 

Do you need three coats of polyurethane?

For surfaces that are exposed to wear, you need three coats of polyurethane. Although the standard coating consists of 2 coats, more coats are better than fewer coats. 

Do You Sand the Final Coat of Polyurethane?

You do not have to sand the final coat. The idea of sanding is to allow the second coating to rest and sit perfectly. Previous coats create an even base for the final coat. Advise you to spray or spread it, leveling it so that it gives a beautiful finish. Sanding the final coat leaves you with a dull and rusty look. For a matt look, sanding is appropriate. 

How Long Does Polyurethane Take to Dry?

Oil-based polyurethane takes 24 hours to dry, whereas water-based polyurethane takes 6 hours to dry. It depends on the type of polyurethane. 

David D. Hughes
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