Varnish will turn sticky (or tacky) if you apply too many coats too soon, if there’s improper drying conditions, or if the surface wasn’t prepared properly.
To fix sticky varnish, use mineral spirits and wipe off the excess, or remove the varnish and re-apply it.
Tacky varnish can eventually dry if the tackiness is caused by low temperature (or high humidity) or because you applied too many coats. But, if the tackiness is caused because of improper surface preparation, the tacky varnish won’t dry.
Why Does Varnish Turn Sticky?
Varnish turns sticky for the following reasons.
- You Applied Too Many Varnish Coats.
- Humid Drying Conditions.
- You Applied it Over a Wet (Damp Surface).
1. You Applied Too Many Varnish Coats
Varnish turns sticky if you apply too many coats as dry time will increase and it takes the extra coatings longer to dry.
If you re-coat varnish too soon, the evaporation process of the existing coating will be delayed, and the solvent will prevent the new coating from adhering or drying.
2. Humid Drying Conditions
Varnish will turn sticky and take longer to dry if the temperature is lower than 50°F (10°C) and the humidity levels are higher than 50%.
Low temperature and high humidity levels will delay the solvent evaporation process, which increases the varnish dry time and turns it sticky.
3. You Applied it Over a Wet (Damp Surface)
Varnish will turn sticky if you apply it over a wet (or damp) surface. The water (moisture) on the surface will prevent the varnish from drying and adhering properly, creating a tacky or sticky finish.
The moisture level must be lower than 15% for the varnish to dry and adhere properly.
A water leak underneath the varnish finish will cause it to turn sticky, too. Always inspect the surface before painting or sealing it.
Does Tacky Varnish Eventually Dry?
Tacky varnish does eventually dry if the tackiness is caused by low temperature (or high humidity), if you applied too many coats, or if you didn’t wipe off the excess.
Once the temperature rises and the humidity levels decrease around the varnish coating, the evaporation process will speed up and the finish will dry. Also, once you remove the excess varnish coats, the remaining will eventually dry.
Tacky varnish doesn’t eventually dry if the tackiness is caused by water leaks, wet moisture, or improper surface preparation. If the varnish coating has been tacky (or sticky) for several days, it won’t dry and you must remove it.
If the tacky varnish is caused by a water leak, the underneath water (or moisture) will prevent the varnish from drying until you either fix the water leak or remove the water from the surface. In most cases, you must remove the varnish, fix the surface issues (water leak), and re-apply the sealer.
How Long Does Varnish Take To Dry?
Water-based varnish takes around 6 hours to dry between coats and 24 hours to cure (fully dry). Oil-based varnish takes around 24 hours to dry between coats and 5-7 days to cure (fully dry).
The exact dry time depends on the drying conditions, such as temperature and humidity levels, the type of varnish, and the number of coats. For instance, the sealer dries faster if the temperature is higher and humidity is lower.
For varnish to dry and cure, its solvent (water or oil) must evaporate from the coating and the coating must polymerize. Once the sealer dries, it produces a glossy moisture-resistant finish.
If the varnish has been tacky (or sticky) for more than three (3) days it won’t dry and you must remove it. A tacky varnish will accumulate and attract too much dirt and create a dark and dirty finish.
How To Fix Sticky Varnish?
To fix sticky varnish, do the following things.
- Use Mineral Spirits and Wipe off The Excess.
- Remove the Varnish and Re-apply It.
1. Use Mineral Spirits and Wipe off The Excess
If varnish is sticky because you applied too many coats, use mineral spirits to soften the varnish coating, wipe off the excess, and leave the remaining to dry.
The tools you need for this method are listed below.
- Clean rags
- A paintbrush
- Fine-grit sandpaper
- Mineral spirits
To fix sticky varnish with mineral spirits, do the following things.
- Damp a rag with mineral spirits.
- Use the dampened rag to wipe the sticky varnish.
- Wait a few minutes.
- Remove the excess varnish.
- Allow the remaining to dry.
- If the varnish finish is too thin, touch up with one (1) more coat.
2. Remove the Varnish and Re-apply It.
If the sticky varnish is caused by a wet surface, water leak, or improper surface preparation, remove the varnish, fix the surface issue, and re-apply the sealer.
If the sticky varnish is caused by improper surface preparation, the finish won’t dry as the water (moisture) on the surface will prevent that. Unless you fix the surface, the finish will peel off eventually.
The tools you need for this method are listed below.
- Paint scraper or putty knife
- Fine sandpaper
- Mineral spirits
- A plastic bag
- Paintbrushes
- Varnish
To remove the varnish and re-apply it, do the following things.
- Pour mineral spirits directly over the finish.
- Wait 5 minutes.
- Wipe the varnish with a cloth.
- Re-apply the mineral spirits to the remaining.
- Wait 5 minutes.
- Scrape the varnish off the surface.
- Remove the mineral spirits residue from the wood.
- Fix the surface issues, such as water leaks.
- Wait for the wood to dry.
- Re-apply the varnish.
What Happens If You Don’t Wipe Off Excess Varnish?
If you don’t wipe off excess varnish, the finish may turn sticky, tacky, or peel off. Excess varnish is a result of applying too many coats in a short period of time.
If you apply too many coats, the excess varnish won’t dry and will remain on the surface until it peels off. Even if the remaining varnish dries, the finish will look blurry.
It’s recommended to wipe off excess varnish 30 minutes after applying it. If the excess is too hard to wipe off, damp a rag with mineral spirits and wipe it off.
Can You Paint Over Sticky Varnish?
You can’t paint over sticky varnish as the paint won’t adhere to it and will peel off too. A sticky varnish isn’t rigid (hard) and will prevent paint penetration and adhesion.
If you paint over sticky varnish, the finish won’t dry and the colorants of the paint will mix with varnish and create a discolored finish. If that happens, you must remove the entire finish, dry the surface, and re-apply it.
