How to Fix Varnish Mistakes? (6 Fixes Included)

Applying varnish is one thing; applying varnish without mistakes is a completely different matter. Due to the thickness and slow-dry time of varnish, it’s very common to run into problems before, during, and after applying varnish.

Today, we are going to look at common varnish mistakes, why they occur, and how to fix them. Sweet right? Let’s dive in.

1. Bubbles on Varnish?

The first varnish mistake on the list is bubbling varnish and this usually happens after varnish application.

When you see bubbles forming on your varnish coat after applying it, it’s a problem. If you don’t address the problem, some of the bubbles will pop causing tears and holes in the varnish that will allow air and moisture to get in and eventually ruin the finish.

Why Does Varnish Bubble?

There are a few reasons for bubbles developing in varnish but the most common reason is air. When air pockets get trapped in your varnish, each coat you apply will develop bubbles meaning that the air is trying to get out. If the bubble pops, the air will rush out leaving a tiny gap in your varnish.

Here are other reasons for bubbles in varnish:

Moisture Leak – When moisture (or water) gets under your varnish coating, the varnish will develop bubbles. In case you didn’t know, air exists in water.

So, the water that gets trapped under your varnish contains air and water. Both of these elements will cause bubbles a few hours after getting in the varnish. The most likely cause of moisture in varnish is when you apply the varnish on a wet surface.

You Stirred the Varnish Too Fast – When you stir varnish too quickly, you’ll force the varnish to mix with air. These air pockets will get trapped in the varnish and cause bubbles.

Next, let’s find out how to get rid of bubbles in varnish.

How To Fix Bubbles In Varnish?

To fix bubbles in varnish, you’ll have to pop the bubbles, sand the varnish down to the wood, and reapply the varnish correctly. Here is a guide for this:

  1. Pop the bubbles using a razor or needle
  2. Use a plastic putty knife to scrape the varnish off of the wood
  3. Sand down the remaining varnish till you get to the wood – use fine-grit sandpaper
  4. Wipe and remove dust
  5. Reapply up to 3 coats of the varnish – leave enough dry time and sand between coats.

Note: Though bubbles can be fixed by laying another coat on the bubbled varnish, this is only a temporary fix. If you do this, the new coat will eventually develop bubbles because you haven’t gotten rid of the trapped air in the existing varnish.

2. Yellowing Varnish?

Another common problem with varnish is yellowing and this happens a few weeks or months after applying the varnish.

This is when the clear and transparent varnish layer starts to develop yellow tints. The yellowing often starts at the edges of the varnish and this problem is common with oil-based varnishes.

Why Does Varnish Turn Yellow?

Varnish starts to develop a yellow or amber-like tone due to the presence of oily deposits in the varnish coating. This problem affects oil-based varnishes.

Since the varnish is dissolved in natural or synthetic oil, there will be oil deposits in the varnish. When the varnish dries, these oil deposits will be left behind and will begin to tint the varnish after a few weeks.

Though varnish turns yellow, you should know that the yellowing isn’t severe. In fact, the yellowing is often unnoticeable because it blends into the tone of the wood.

How To Fix Yellowish Varnish?

Unfortunately, there is no way to fix yellowing in varnish. You can sand the varnish but you’ll eventually sand down the entire varnish because each coat will turn yellow. You can touch up the varnish but the new coat will still turn yellow too.

The only way to fix yellowing varnish is to avoid it. If you don’t want the yellowing, you should apply a water-based varnish. Since water-based varnishes are not dissolved in oils, there are no oil deposits to tint your finish.

3. Varnish is Turning White?

Whitish varnish as it’s usually called is a problem that usually develops several months after applying the varnish. This is when the clear varnish coat starts to turn white or milky. This makes the entire finish look pale and unattractive.

Why Does Varnish Turn White?

Here are reasons your varnish coat is turning white:

Water Exposure – When your varnish coating is exposed to water, the varnish will develop white water rings which will spread across the entire coat and turn the varnish white or milky.

The white-water rings develop because there is moisture trapped in the varnish. The usual cause of water on varnish is when you clean or wipe your varnish with a wet rag or mop.

Chemical Cleaners and Soda – Your varnish coating can also turn white when you use chemical cleaners, soda, or bleach to clean the varnish. In this case, the tone of the varnish will fade gradually till the finish turns white. Chemicals and acid in bleach are responsible for the whitish appearance.

UV Exposure – Your varnish can also turn white when exposed to UV rays from the sun. The heat and UV rays will gradually fade the varnish tone. To prevent this fading, it’s advised to use varnish with UV blocker additives like exterior varnish.

How To Fix Whitish Varnish?

The first step to fixing whitish varnish is to find out the cause of the whitish appearance.

If the white look is caused by UV exposure or chemical cleaners, you’ll need to touch up the area with new coats of exterior varnish (ensure it has UV-blocking additives).

If the white appearance is caused by moisture, you need to sprinkle baking soda on the varnish and leave it for 24 hours. The baking soda will soak the moisture.

4. Varnish is Cracking?

Cracking varnish is another problem that develops after applying the varnish. This is when the varnish coat starts to crack or split.

These cracks usually develop first as hairline cracks – tiny lines on the varnish. Over time and due to the effects of the elements, these cracks start to widen and can eventually cause large holes in the varnish.

Why Does Varnish Crack?

The main reason for cracking varnish is over-thinning.

Due to the thick nature of varnishes, painters often thin the paint with mineral spirits to make it easier to apply. However, you are not to thin the varnish to more than 50% mineral spirits.

If you use too many mineral spirits or paint thinner, the varnish will become too thin when you apply it. Since the varnish is thin, it will take little contact to cause it to crack and break. A dropped item on over-thinned varnish will cause it to crack.

Here are other reasons for cracked varnish:

Pest Activity – If you apply the varnish over termite-infested wood, the varnish will crack within days as the termites move around and chew on the wood underneath.

Varnish Dried Too Fast – If your varnish dried too quickly, the paint particles will not bond properly. This will cause weak adhesion in the varnish causing it to split and develop cracks. Sometimes, these cracks will form a web across the varnish coating.

How To Fix Cracked Varnish?

If the cracks aren’t deep or much on the varnish, you can fix them by sanding the cracked spot and buffing it with polish or wax. However, if the cracks are deep or plenty on the varnish, the only way to fix it is to strip the varnish and apply new coats. Here is a guide for this:

  1. Scrape the cracked varnish with a putty knife
  2. Sand the remaining varnish down to the wood
  3. Apply a primer or wood stain (if required) – wood stains add color to the transparent varnish
  4. Apply up to 3 coats of varnish on the wood.
  5. Leave enough dry time to prevent cracking.

5. Wrinkles in Varnish?

It’s a common mistake for varnish coats to develop wrinkles. This is when the varnish coating starts to shrink or pull together. Sometimes, these wrinkles develop waves across the entire varnish coating.

Why Does Varnish Wrinkle?

The main reason for wrinkles in varnish is surface drying – this is when only the top layer of the varnish dries while the bottom layer remains wet.

The wet undercoat causes the entire varnish to move and shift since it’s not yet solid. As the varnish expands and shifts, it causes a web of wrinkles to form on the varnish.

Here are other reasons for wrinkles in varnish:

Water Leak – If there is a water leak beneath the varnish, the bottom part of the varnish will become wet and this will cause the varnish to absorb water and develop wrinkles.

You Applied the Varnish in Cold Weather – Varnish while wet is very sensitive to the weather. If you applied the varnish in cold temperatures or during the winter season, the varnish coat can shrink to cause wrinkles on the paint.

How To Fix Wrinkled Varnish?

If the wrinkles were caused by water exposure, you might get away with it by using a hairdryer to allow the varnish to dry properly. In some cases, this will work but, in most cases, it won’t.

The best way to fix wrinkles in varnish is to strip the varnish coating, apply a waterproof varnish primer paint, and reapply the varnish. Here is a guide for this:

  1. Use a paint scraper to scrape off the wrinkles varnish – since the varnish is wet, it would be easy to scrape it off
  2. Wipe the wood with mineral spirits and leave it to dry
  3. Sand the wood using fine sandpaper
  4. Remove dust
  5. Apply waterproof primer paint and leave for at least 2 hours to cure
  6. Apply up to 3 coats of the varnish – leave enough dry time and sand between coats of the varnish.

6. Varnish is Peeling Off?

Peeling varnish occurs at random – it can happen a few days after applying the varnish or after a few years. This happens when parts of the varnish coating start to break and peel off of the surface.

Why Does Varnish Peel-Off?

The main reason for peeling varnish is old age. As fine and durable as varnish is, it also has a time limit. When the varnish reaches that time limit, it begins to fall off gradually meaning that you need a new finish. It takes between 20 and 30 years for varnish to reach this stage.

If your varnish is not 20 years old and it’s beginning to peel off of the surface, here are a few other causes to look at:

You Varnished Over a Filthy Surface – If your varnish is peeling off a few days after applying it, this is the reason. When you apply varnish over a dusty or filthy surface, the varnish will not adhere well to the surface.

Instead, the varnish will stick to the loose particles of dirt on the surface. The loose nature of the dirt causes them to move and since that’s the base of your varnish, the varnish will peel off bit by bit.

Sunlight and High Temperature – If you expose your varnish to direct sunlight, the heat and rays from the sun can weaken the adhesive in the varnish causing it to peel off gradually. Applying varnish on hot surfaces can also cause the varnish to peel because varnish is not heat resistant.

How To Fix Peeling Varnish?

The only way to fix peeling varnish is to scrape the varnish off, fix the problem, and reapply the varnish. Here is a guide for this:

  1. Scrape off all of the peeling coats
  2. Sand down the remaining varnish till you reach the surface underneath
  3. Remove dust and apply a waterproof varnish primer paint
  4. Apply up to 3 coats of varnish and leave to dry – ensure to leave enough dry time and sand between coats of the varnish.

How To Prevent Varnish Mistakes?

  1. Allow enough dry time between coats
  2. Sand each coat before applying the next
  3. Follow manufacturer’s instructions when applying varnish
  4. Remove existing varnish before applying a fresh coat
  5. Ensure the surface is clean and dry before applying varnish
  6. Use the right type of varnish
  7. Always wipe off excess varnish after application
  8. Thin the varnish in the correct ratio – less than 50% paint thinner
  9. Don’t apply less than or more than the recommended number of varnish coats
  10. Use the right varnish applicator.

Final Words

In summary, varnish application takes some time to perfect, and while on that journey of perfection, you are bound to make any of the above-listed mistakes.

But don’t fret because now you know how to fix those mistakes and more importantly, how to avoid them.

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