How Can You Easily Thin Shellac? [In 3 Easy Steps]

You have tried refurbishing your old furniture with your Shellac. But, it’s not sealing your wood properly. This is what happens when your shellac doesn’t keep up its natural consistency. That’s when you should thin your shellac.

So, how to thin shellac?

Alcohol is the key ingredient to thin shellac. Methanol and ethanol are the two major alcohols that can diffuse and thin shellac. Methanol is a hazardous substance since it is toxic. Pure ethanol is another option to thin and clean shellac. But denatured alcohol at 95% could be the best solvent for thinning your shellac flakes.

This is only just some hints to thin shellac. We’ve provided you with a complete step-by-step process to thin shellac.

So, if you want to know, let’s get started.

Why Do I Need To Thin Shellac?

Shellac is a resinous substance that’s obtained as dry flakes. This substance is used to seal the gaps in the woods. It is also used to add evenness or intensify the beauty of the wood. Shellac has properties to seal out the moisture and possess strong insulation qualities.

Now, thinned Shellac works as an outstanding stain barrier coat. It especially works on softwoods and problematic or end grain before staining out. 

The reason for thinning the shellac is to help it penetrate the gap between the bands. Moreover, it‘s easy to brush, spray, wipe, pad and even dip when the shellac is thin.

how to thin shellac

3 Effective Methods on How to Thin Shellac

By now you know why you need to thin shellac. In the following, you’ll know what important elements you need to thin your shellac.

Thinning Shellac concerns quite a few steps. So, let’s jump into those-

Method 1: Thin with Rubbing Alcohol

Shellac can be thinned and cleaned by Rubbing Alcohol. But, Rubbing alcohol like Isopropyl contains 30% water in its solution. So there’s a chance that water can produce a cloudy residue in the shellac. This will spoil a shellac finish.

The water might turn the shellac to white or blush. Try to have your hand on 95% – 100% Pure Propanol or Isopropyl alcohol. With this, Thinning Shellac will be so easy to do.

So, to have a solution of pure alcohol, mix the rubbing alcohol with shellac flakes.

Method 2: Thin with Denatured Alcohol

Denatured alcohol is the best thinner and clear-up solution for shellac. Denatured Alcohol or Methylated spirit is formed with ethanol and specific additives. 

This alcohol works as a cleaning agent, sanding aid, and exterminator as a solvent. As for the shellac, it has the quality of cleaning substances and gives it a form. Plus it is 30% more effective than other alcohol solvents. For this reason, we use this alcohol to thin and clean shellac.

Method 3: Thin with Methanol

Wondering how to thin shellac without denatured alcohol

Well, methanol is quite effective for thinning shellac. However, if you are exposed to the vapours for an extended period, it is highly dangerous. So, unless you’re dealing with good exhaust, methanol isn’t a good idea.

You can use either one of these methods to make a cut. Preferably, massive people use Denatured Alcohol to thin shellac. But Methanol and Pure Isopropyl are good options too. So, just use the one that you can easily access. 

Step by Step Process to Thin Shellac

You can use either of the Rubbing Alcohol, Methanol, Denatured Alcohol to thin shellac. Any solvents work as an effective cut-off agent as long you follow the steps right. 

Now, we’ll head you to the complete process of thinning your shellac-

Step 1: Dissolving and Mixing Flake Shellac

First, combine in a dark plastic or glass with a tight-fitting covering. If a clear container is used, keep it in a cool and dark place. 

Immerse the flake shellac in roughly half of the total alcohol. Let it settle for 24 hours or longer (crush the button shellac to hasten to dissolve). Continue stirring from time to time until dissolved. 

Step 2: Set the “Cut”

“Cut” determines the consistency of shellac. Three pounds of shellac flakes per gallon of Denatured Alcohol solvent equals a three-pound cut. You can use this ratio for other alcohol solvents as well.

If you are thinning shellac for the first time, start with a light consistency. This could be about a 1-1.5 pound cut. 

Use a 2:16 ratio of shellac flakes to alcohol. This means 2 ounces of shellac flakes get dissolved in 16 ounces of alcohol. This is suitable for 1 pint of 1 pound cut liquid shellac. 

Heavier liquid cuts can work for thinning shellac. But it is better to have several thin layers rather than a few thick ones.

Step 3: Purify the Mixture

After the shellac has completely dissolved, filter it through a fine-mesh cheesecloth. This will remove any impurities from the shellac. 

Then the liquid shellac should be thoroughly shaken or mixed before use. Let it set aside for 24 hours and that’s it.

After perfectly dissolving, we can get thinner shellac for our work!


Question: How do you dilute shellac?

Answer: Start slowly while diluting the shellac. Dilute 100 ml of the prepared shellac in a glass jar to get a sense of how much alcohol to use. You can always add more. But you won’t be able to take it away.  Stir the solution well and set it aside for 15-20 minutes. Check the colour and wait for 2 minutes if it’s necessary.

Question: Can you thin shellac with mineral spirits?

Answer: Mineral spirits is a petroleum-based substance that is incompatible with shellac. Though it is thinner for varnish, it will also dissolve wax. So, you can’t thin shellac with mineral spirits. 

Question: Can you thin shellac with acetone?

Answer: Because of the acetone, green lacquer thinner cleans up well. And it works as effectively as the conventional lacquer thinner. So yes, you can use acetone to thin shellac.


Hopefully, now you’ve got some ideas about how to thin shellac. With the above instructions, you can easily perform the process. 

So, give it a shot. You might get surprised by the good results.

That’s all for today. Let us know how you carried it out.

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