Water-based varnish takes around 6 hours to dry between coats and around 24 hours to cure (fully dry). Oil-based varnish takes around 24 hours to dry between coats and around 5-7 days to cure (fully dry).
Oil-based varnish takes longer to dry because its solvent (oil) takes longer to evaporate from the coating.
How Long Does Varnish Take To Dry Between Coats?
Water-based varnish takes around 6 hours to dry between coats, while oil-based varnish takes around 24 hours. The dry time between coats refers to the time to wait before applying the next coat.
The exact varnish dry time depends on the room humidity, temperature levels, type of varnish, and the number of coats. For instance, if you apply more coats the finish will take longer to dry.
For varnish to dry, the solvent (water or oil) must fully evaporate and the coating must become hard or rigid.
Water-based varnish uses water as the solvent and dries faster than oil-based varnish. Since water evaporates fast from the coating, the sealer also dries fast.
To know if the varnish coating is dry enough for a re-coat, inspect the finish. If the finish is sticky, it hasn’t dried yet. If the finish is rigid and has a dry appearance, it has dried.
To know if the varnish coating is dry between coats, use fine-grit sandpaper (220-grit). Swipe the fine-grit sandpaper over the finish, if the sandpaper gets clogged, the finish hasn’t dried. If the sandpaper moves freely, the finish is dry.
A varnish coating is dry when the following things happen.
- The coating isn’t sticky or tacky.
- The coating feels hard.
- You can sand the coating without the sandpaper getting clogged.
- The coating has a shiny or glossy appearance and reveals the wood grain.
How Long Does Varnish Take To Cure (Fully Dry)?
Water-based varnish takes around 24 hours to cure (fully dry), while oil-based varnish takes around 5-7 days to cure.
The varnish finish reaches its maximum durability, adhesion, and water-resistance level once it cures (fully dries).
If you use or clean a varnish finish before it has cured or fully dried, the finish can peel off or turn sticky. It’s recommended to wait at least one (1) week before exposing the finish to water or cleaning.
How To Speed Up Varnish Dry Time?
To speed up varnish drying time, do the following things.
- Use a Hair dryer.
- Use Paint Thinner.
- Improve the Air Circulation.
1. Use a Hair dryer
Use a hair dryer to increase the heat around the varnish coating so the solvent (water or oil) evaporates faster.
To use a hair dryer to speed up the varnish drying time, do the following.
- Turn on the hair dryer.
- Set the heat to medium.
- Move the hair dryer around the varnish coating for a few minutes.
- Wait 5 minutes.
- Re-do the whole process.
- Allow the varnish coating to dry naturally.
Don’t fully dry the varnish coating with a hair dryer as the paint particles won’t dry naturally nor have enough time to bond, and the finish can develop paint cracks.
2. Use a Paint Thinner
To make varnish dry faster, thin it with paint thinner before applying the sealer. Thin varnish coats will dry faster as there’s less solvent (oil or water) to evaporate and the coating becomes hard or rigid faster.
To thin oil-based varnish, use turpentine, mineral spirits, or paint thinner. To thin water-based varnish, use water.
To thin varnish before applying it, do the following things.
- Pour varnish into a clean paint bucket.
- Add paint thinner to the varnish in a ratio of 1:3 (1 part thinner to 3 parts varnish).
- Stir the mixture for around 5 minutes.
- Apply the thinned varnish.
Don’t over-thin varnish as it will create a weak finish that may peel off.
3. Improve the Air Circulation
Varnish dries faster if you improve the air circulation around the coating because the solvent will evaporate faster.
To improve the air circulation around the varnish coating, do the following things.
- Open all windows, doors, and air vents.
- Turn on the fans and direct them toward the coating.
- Set the air conditioner to “blow” or “fan.”
Other methods to speed up varnish drying time are listed below.
- Turn on the dehumidifier to reduce moisture content (humidity) in the air.
- Apply the sealer only if the temperature is higher than 50°F (10°C) and the humidity levels are lower than 50%.
- Apply light varnish coats.
How Long Do Different Varnish Types Take to Dry?
Spirit Varnish
Spirit Varnish takes around 24 hours to dry between coats and around 5-7 days to cure (fully dry).
This varnish dries fast as it doesn’t have oils on its formula and it’s made of resins, solvents, and alcohol.
Acrylic Varnish
Acrylic varnish takes around 12 hours to dry between coats and around 24 hours to cure (fully dry).
Exterior Varnish
Exterior varnish takes around 24 hours to dry between coats and 5-7 days to cure (fully dry).
Exterior varnish is formulated with extra protective additives to make the finish more durable for outdoor weather elements. The extra additives increase the dry time of the sealer as more solvent has to evaporate.
Polyurethane Varnish
Polyurethane varnish takes around 24 hours to dry between coats and around 3 days to cure (fully dry).
