1. Methylated Spirits (Denatured Alcohol) – The Best and Most Common Choice
The most widely used and recommended alcohol for French polishing is methylated spirits, also known as denatured alcohol.
Why it's ideal:
- Dissolves shellac flakes quickly and thoroughly
- Evaporates at the right speed for smooth application
- Leaves a clear, clean finish
- Easily available and affordable
- Works perfectly for both polishing and "spiriting off"
In Australia, purple-dyed methylated spirits is the standard and works extremely well for French polishing.
2. Industrial Alcohol (Ethanol) – High Purity, Professional Use
Pure or near-pure ethanol is highly effective for French polishing, especially in workshops.
Benefits:
- Very clean burning
- Minimal residue
- Produces a clear, crisp polish
- Ideal for premium, high-gloss finishes
Downside:
- Harder to buy because it is regulated
- More expensive
- Not necessary for most projects
Restoration professionals sometimes prefer high-grade ethanol for museum-quality work or large instruments.
3. Isopropyl Alcohol (IPA) – Not Ideal
Some people ask whether they can use isopropyl alcohol.
Short answer: No.
Reasons:
- Doesn't dissolve shellac as well
- Slower evaporation leads to streaks
- Can soften or cloud the finish
- Not suitable for polishing or thinning
It is acceptable only for cleaning tools — not for making shellac polish.
4. Methanol – Effective but Unsafe
Methanol dissolves shellac very well, but it is very toxic and unsafe, especially indoors.
Issues:
- Highly poisonous
- Dangerous fumes
- Absorbs through skin
- Not recommended for home or professional use
Most modern restorers avoid methanol entirely.
5. Denatured Alcohol vs Pure Alcohol — What's the Difference?
Denatured alcohol contains small additives to make it undrinkable. These additives don't affect the performance for French polishing.
The key factors are:
- Evaporation rate
- Purity
- Absence of oily additives
High-quality methylated spirits from a hardware store is perfectly suitable.
What Alcohol Should You Use for the Best Results?
✔ Best Overall:
Methylated Spirits (Denatured Alcohol)
Affordable, reliable, safe enough for indoor use, and perfect for dissolving shellac.
✔ Best Professional Choice (Premium):
High-purity Ethanol (95–99%)
Ideal for high-end restorations and instrument finishing.
✘ Avoid:
- Isopropyl alcohol (IPA)
- Methanol
- Alcohols with oils, scents, or additives
Why the Right Alcohol Matters
Using the correct alcohol ensures:
- Shellac dissolves evenly
- The pad glides smoothly
- Layers dry clean and streak-free
- The finish develops a clear, rich shine
Poor-quality alcohol leads to cloudiness, drag marks, and uneven layers.