I’ve made my fair share of wooden coasters over the years—usually as a way to use up scrap wood from bigger projects.
At first, I didn’t put much thought into the finish… until I started seeing water rings and dull, worn-out surfaces after just a few uses.
That’s when I realized not all finishes are up to the task.
Some look great but won’t stand up to moisture, while others give solid protection that lasts.
So in this post, I’m sharing the 5 finishes I trust for wooden coasters—and 2 I learned to avoid the hard way.
Two Types of Finishes: Oil vs. Film
Wood finishes fall into two broad categories: penetrating oils and film-forming finishes. Each works differently and offers unique benefits depending on the project.
Penetrating oils soak into the wood fibers to enhance the grain and offer basic protection.
Film finishes sit on top of the surface, forming a barrier against water, scratches, and wear.
Best Finishes for Wooden Coasters
These finishes offer the most reliable durability, waterproofing, and overall performance.
1. Water-Based Polyurethane
Water-based poly dries fast, has minimal odor, and is easy to apply. It forms a waterproof, protective layer without darkening the wood.
Multiple coats (4 to 6) are needed for full protection. It’s a great choice for indoor coasters with minimal hassle.
Why I like it:
- Dries fast with little odor
- Inexpensive and I usually have it on hand
- Doesn’t change the wood’s natural look (in general)
- Easy cleanup and low toxicity
- Great for light-duty or decorative coasters
2. Oil-Based Polyurethane
This finish forms a thick, hard shell that is completely waterproof. It’s extremely durable and ideal for coasters that see regular use.
The tradeoff is a strong odor and long dry time. With proper ventilation, it delivers long-lasting results.
Why I like it:
- Long-lasting protection with fewer coats
- Fully waterproof and highly durable
- Great for heavy use or outdoor coasters
- Adds a warm amber tone to the wood
3. Lacquer
Lacquer dries quickly, creates a smooth surface, and resists water and wear. It’s easy to apply and available in spray cans for quick jobs.
It doesn’t yellow over time and needs little maintenance. Great for coasters with a clean, glossy look.
Why I like it:
- Clean, modern-looking finish
- Dries fast—great for batching coasters
- Resists moisture and everyday wear
- Spray can option is beginner-friendly
4. Varnish
Varnish offers excellent water resistance and protection against scratches. It forms a tough, clear coating ideal for coasters used daily.
It tends to have a yellowish tint but performs well indoors or out. A solid, traditional choice for hard-wearing projects.
Why I like it:
- Ideal for rustic or classic finishes
- Durable and water-resistant
- Holds up well to heat and spills
- Good for both indoor and outdoor use
5. Tung Oil
Tung oil is a natural, food-safe finish that hardens as it cures. It penetrates deep into the wood and provides moderate water resistance.
You’ll need several coats and proper drying time. While not fully waterproof, it’s better than most oils for handling moisture.
Why I like it:
- A good option when avoiding synthetics
- All-natural and food-safe
- Gives wood a rich, hand-rubbed look
- Soaks in deep for decent protection
Finishes to Avoid for Coasters
These options don’t provide the moisture protection needed for coasters.
Danish Oil
Danish oil dries to a nice satin finish and is easy to apply. But it’s only water-resistant—not waterproof.
It works well for furniture, but not for coasters that deal with wet glasses. Better left for low-contact indoor items.
Why I don’t recommend it:
- Better suited for shelves, desks, or decorative pieces
- Only resists light spills—won’t block water rings
- Not reliable for daily coaster use
- Varies by brand, so results aren’t consistent
Linseed Oil
Linseed oil enhances the wood grain and penetrates deeply. However, it takes a long time to dry and doesn’t repel water.
Even boiled linseed oil doesn’t offer enough protection. It’s not suitable for anything that faces repeated exposure to moisture.
Why I don’t recommend it:
- Best used on indoor pieces not exposed to liquids
- Extremely long drying time (especially raw)
- Doesn’t protect against moisture or spills
- Needs frequent reapplication to maintain
Final Thoughts
If you’re going to put time into making wooden coasters, it’s worth choosing a finish that holds up.
Water rings, dull spots, and damage can all be avoided with the right protection.
For the best results, stick with water-based poly, oil-based poly, lacquer, varnish, or tung oil—each one offers solid durability and moisture resistance.
And while Danish oil and linseed oil have their place in the shop, they’re just not the right fit for something that deals with wet glasses day after day.
Choose the right finish upfront, and your coasters will keep looking good no matter how many drinks they see.