Tung oil and linseed oil are both popular wood finishes derived from natural oils. While they share some similarities, there are important differences between these two oils that users should understand before applying them. This comprehensive guide compares tung oil and linseed oil to help you determine which is better for your next wood finishing project.
An Overview of Tung Oil and Linseed Oil
Tung oil, also known as China wood oil, is extracted from the nuts of the tung tree. Linseed oil, also called flaxseed oil, is derived from the seeds of the flax plant. Both oils are considered “drying oils”, meaning they harden and cure into a solid protective finish after exposure to air.
Tung oil has been used for centuries in China as a wood finish, waterproofing agent, and wood preservative. It was later introduced to the West around the 1900s. Linseed oil has an even longer history, being used as a wood finish since ancient Egypt. Today, both oils are popular options for finishing and protecting wood.
When applied to wood, linseed oil and tung oil penetrate deep into the pores to provide a flexible, breathable seal. They accentuate the natural color and grain of wood beautifully. The main considerations when choosing between the two oils are drying time, durability, appearance, and cost.
Key Differences Between Tung Oil and Linseed Oil
Drying Time
One of the biggest differences between tung oil and linseed oil is their drying time.
- Tung Oil – Tung oil dries remarkably fast, especially compared to linseed oil. A thin layer of tung oil will usually dry to the touch within 30-60 minutes under normal conditions. Several thin coats can be applied in one day.
- Linseed Oil – Raw linseed oil dries very slowly, sometimes taking 3-7 days for a thin coat to fully harden. This makes the finishing process lengthier compared to tung oil. However, solvent-thinned “boiled” linseed oil dries much faster, in about 24 hours.
Tung oil’s rapid drying time makes the application process quicker and easier. Multiple coats can be built up in a single day to achieve the desired finish. Linseed oil’s slower dry time means you need more patience between coats.
Durability
When fully cured, both tung oil and linseed oil produce durable, water-resistant finishes. However, tung oil is widely regarded as the more durable of the two finishes:
- Tung Oil – Forms an exceptionally tough, flexible, and waterproof finish that resists scratches, heat, water, acid, alkali, and abrasion better than linseed oil.
- Linseed Oil – Provides good water resistance but is less scratch and abrasion resistant than tung oil. Not as durable for high-wear surfaces.
Tung oil is one of the most durable natural oil finishes available. Many sources consider tung oil more durable than modern varnishes and polyurethanes. This makes it ideal for high-traffic wood surfaces like floors and furniture. Linseed oil is best suited for low- to medium-wear applications.
Appearance
Both tung oil and linseed oil enhance the natural appearance of wood:
- Tung Oil – Provides a deep, slightly amber tone that brings out the natural color and grain of wood beautifully. Leaves a smooth, silky sheen.
- Linseed Oil – Has little color on its own so provides a more neutral, natural look. Imparts a gentle satin luster.
Tung oil offers a richer, warmer visual effect that subtly pops the wood grain. Linseed oil is more clear and neutral. Neither oil feels oily or greasy after drying. Tung oil leaves a smoother, more lustrous finish.
Cost
- Tung Oil – Significantly more expensive than linseed oil. Costs $15-30 for a 16 oz bottle.
- Linseed Oil – Very affordable, available for $5-15 per 16 oz. Far cheaper than tung oil.
The higher cost of tung oil can be prohibitive for large projects. Many woodsworkers reserve tung oil for smaller surfaces and use linseed oil when price is a concern.
Additional Key Differences:
- Tung oil does not require any chemical thinners. Linseed oil often needs solvents to improve drying time.
- Tung oil provides good UV resistance. Linseed oil finishes degrade faster in sunlight.
- Tung oil cures to a harder, more scratch-resistant film. Linseed oil remains more flexible when dry.
- Tung oil is more resistant to mildew and fungal growth.
- Tung oil contains natural insect and water repellent properties.
- Tung oil is safe for children’s toys, cutting boards, and surfaces that contact food. Raw linseed oil is not FDA-approved for such uses.
Advantages of Tung Oil Finishes
Tung oil offers several unique advantages that make it a premium wood finish:
Exceptional Durability – Cures into one of the toughest, most water-resistant natural finishes available. Withstands scratches, water, heat, and abrasion better than most finishes.
Rapid Drying Time – Thin coats dry remarkably fast, in about 30-60 minutes. Allows multiple applications per day for faster finishing.
Enhances Wood Grain – Penetrates deeply to accentuate figure and grain. Has a warm, slightly amber tint that gives wood a rich, natural look.
Easy Application – Can be applied easily by rag, brush, or spray. No need to dilute or mix with chemical thinners.
Non-Toxic – Made from natural tung oil. Contains no VOCs or toxic solvents. Safe for children’s toys and food contact surfaces when cured.
Flexible Finish – Resists cracking or peeling over time. Expands and contracts with the wood without damage.
UV Resistance – Offers good UV protection to reduce finish breakdown in sunlight.
Mold and Mildew Resistant – Naturally resists fungal growth better than linseed oil.
Tung oil’s fast dry time, durability, and ease of application make it an ideal finish for a wide range of bare wood projects. The premium performance comes at a cost, as tung oil is significantly more expensive than linseed and other oils.
Advantages of Linseed Oil Finishes
Linseed oil provides its own set of useful benefits:
Inexpensive – Available at a fraction of the cost of tung oil. Budget-friendly for large projects.
Prevents Cracking/Checking – Flexible finish moves with wood to prevent cracks from developing over time.
Penetrates Deeply – Absorbs well into porous woods with excellent penetration.
Easy Application – Can be applied by wiping, brushing, or spraying. Minimal equipment needed.
Low Sheen Finish – Provides a smooth, natural-looking satin luster. Not shiny.
Minimal Color Change – Has very little color on its own, allowing natural wood tones to shine through.
Traditional Oil Finish – Long history of use dating back centuries. Familiar option for many.
Non-Toxic When Dry – Made from food-grade flaxseed oil. Safe for children’s items when fully cured.
Raw linseed oil is best suited for indoor surfaces that don’t require ultimate durability. Solvent-thinned boiled linseed oils offer much faster drying times. While not as hardy as tung oil, linseed oil still gives good protection at a wallet-friendly price.
Using Tung Oil on Wood
Tung oil is applied similarly to other penetrating oil finishes:
Surface Preparation – Ensure the wood is clean, dry, and properly sanded. Sanding to 220-320 grit is recommended to allow good penetration into the grain.
Thin First Coats – Apply a thin, even coat using a clean rag or lint-free cloth. Allow 30-60 minutes for the first coat to dry.
Apply Additional Coats – Lightly sand with 400 grit sandpaper between coats to produce an ultra-smooth finish. Add 3-5 thin coats for best durability.
Allow to Fully Cure – Let the oil cure fully for 5-7 days before use. Curing time hardens the finish.
Optional Buffing – Buffing with extra-fine (0000) steel wool once fully cured can further smooth the finish.
Clean Tools Promptly – Clean brushes, rags, and tools with mineral spirits immediately after use.
Tung oil cures slowly in the weeks after application to achieve maximum hardness and water resistance. Gentle surface sanding between coats creates a flawless finish. Always allow proper drying time between coats – applying oil over uncured oil can leave a gummy surface.
Using Linseed Oil on Wood
Linseed oil application involves similar steps as tung oil:
Prep Surface – Ensure wood is clean, dry, and sanded up to 220-320 grit for optimal penetration.
Wipe On Thin Coats – Apply a thin, even layer of oil across the wood grain using a clean rag or brush.
Allow Proper Dry Time – Let oil fully absorb into the wood. Wait 24 hours between coats for boiled linseed oil, and 3-7 days for raw oil.
Add Additional Coats – For durability, apply 3-5 thin coats until wood is saturated. Sand lightly between coats for a smooth finish.
Cure Completely Before Use – Allow linseed oil to cure for 1-2 weeks before regular use. Curing hardens the finish.
Clean Tools – Wipe off excess oil. Clean brushes and rags with mineral spirits to prevent fire hazard from spontaneous combustion.
Applying too much linseed oil at once can create a gummy surface. Maintain thin coats and allow proper curing between layers. Raw linseed oil may darken some woods over time.
Tung Oil vs. Linseed Oil – Which is Better for Specific Surfaces?
Wood Furniture
Tung oil is the best choice for most wooden furniture, both indoor and outdoor:
- Extremely durable, scratch-resistant finish withstands daily wear and tear.
- Waterproof and resistant to spills, foods, and liquids.
- Rapid drying time makes application fast and convenient.
- Enhances natural wood grain beautifully. Leaves a smooth, rich appearance.
Linseed oil works for low-use indoor furniture:
- Provides decent protection for indoor surfaces at a budget-friendly price.
- Flexible finish won’t crack over time as wood expands and contracts.
- Minimal color change allows natural wood tones to shine through.
Wood Floors
Tung oil is ideal for hardwood floors:
- Extreme durability withstands heavy foot traffic over time.
- Waterproof finish resists spills, moisture from cleaning, etc.
- Rapid drying allows quick recoating to refresh worn areas.
Linseed oil is only suitable for very light-duty floors:
- Does not stand up to heavy foot traffic over time. Requires frequent recoating.
- Not waterproof enough for kitchens, entryways, bathrooms.
- Slow dry time makes recoats tedious.
Cutting Boards and Kitchenware
Tung oil is preferable for most cutting boards, butcher blocks, and wood kitchen tools:
- Creates a sanitary, moisture-resistant surface. Minimizes bacteria.
- Dense film resists knife scars over time with proper care.
- Does not turn rancid or impart flavors/odors. Safe for food contact when cured.
Many prefer to use food-grade mineral oil on cutting boards instead of any drying oil. Linseed oil is not FDA-approved for surfaces that contact food.
Children’s Toys and Furniture
Tung oil is ideal for children’s items thanks to its safety:
- When fully cured, forms an inert, non-toxic finish safe for children.
- Resists moisture, saliva, and liquids to maintain durable protection.
- Applies easily to tight corners and small parts.
Linseed oil is not recommended for children’s toys or furniture, since raw linseed oil is not compliant with regulations for child safety when not fully cured.
Outdoor Wood Projects
For exterior wood projects like outdoor furniture, doors, and millwork, tung oil is superior:
- Waterproofing abilities resist rain, snow, and moisture.
- Holds up very well to sun, heat, cold, and freezing temperatures.
- Maintains flexibility so won’t crack, peel, or flake off over time.
Linseed oil provides mediocre exterior performance:
- Lacks the moisture resistance needed for outdoor use. Requires frequent reapplication.
- Prone to UV degradation, yellowing, and wearing away faster than tung oil.
Interior Wood Projects
For interior surfaces like paneling, cabinets, or trim, either oil can provide good protection:
Tung Oil
- Tough, scratch-resistant finish maintains beautiful appearance.
- Resists denting, liquids, and scuffs well. Easy to locally re-coat worn areas.
Linseed Oil
- Much more budget-friendly for large interior projects.
- Minimizes cracks by flexing as wood expands and contracts.
- Subtle sheen enhances natural wood tones.
So while tung oil is superior, linseed oil can be adequate for low-wear indoor surfaces where aesthetics and economy are priorities.
Application Tips and Tricks
Following some best practices will help ensure you achieve the best results from tung or linseed oil:
- Use high-quality, pure oil from a reputable brand. Avoid cheap thinned oils.
- Test on scrap wood first to confirm desired appearance and compatibility.
- Apply in thin coats, only to the point of saturation. Overapplication creates gummy surfaces.
- Allow proper drying time between coats – oil over uncured oil leaves a mess.
- Lightly sand between coats with fine (320-400) grit for an ultra-smooth finish.
- Clean brushes and rags immediately in mineral spirits to prevent spontaneous combustion fire hazard.
- Allow curing fully for 5-7 days before use for maximum hardness.
- Buff cured oil finishes gently with steel wool for a refined sheen.
- Maintain the finish by occasionally re-oiling worn, dry areas. Don’t let it strip completely.
Proper surface prep is also critical prior to applying any oil finish. Sand bare wood progressively up to 220-320 grit so the oil can optimally penetrate the grain. Ensure surfaces are clean, dry, and dust-free before applying.
Safety and Disposal
Oil finishing involves some basic safety precautions:
- Work in a well-ventilated area. Avoid breathing vapors.
- Wear gloves and eye protection. Avoid skin contact – oils can irritate skin.
- Store rags soaked in oil in an airtight metal container until disposal. Oily rags left out can combust.
- Dispose of used rags and steel wool containing oils or solvents properly in accordance with local hazardous waste regulations.
- Keep oils and solvents away from sparks, flames, or other ignition sources.
When dry, both tung oil and linseed oil cure into an inert, non-toxic film safe for human contact. Allow 1-2 weeks full curing time before use for food-safe surfaces. Always check and follow the manufacturer’s safety guidance when using any wood finishing product.
Frequently Asked Questions
Is tung oil food safe when cured?
Yes, when fully cured tung oil undergoes a chemical conversion and becomes inert and non-toxic. Pure tung oil is compliant with FDA regulations for surfaces that contact food like cutting boards and bowls once fully cured (typically 5-7 days).
Should tung oil be diluted?
No. Tung oil does not require any sort of chemical thinner. It can be used pure right out of the can. Occasionally tung oil is cut with citrus solvents to create a wipe-on product, but a full-strength oil generally provides the most durable finish.
How long does it take boiled linseed oil to dry compared to raw?
Raw linseed oil can take 3-7 days for a coat to fully dry. Boiled linseed oil contains metallic dryers and solvents that reduce the drying time significantly, to about 24 hours between coats.
Does linseed oil expire and go bad?
Yes, linseed oil has a shelf life of 1-2 years before it starts to oxidize and become gummy. Store in an airtight container out of sunlight to maximize lifespan. Discard linseed oil that is thick, clumpy, or rancid smelling.
What’s the best way to revitalize an oil finish?
To freshen up an oil finished wood surface that is looking worn or dry, lightly sand to degloss and remove any damaged finish. Wipe on a fresh thin coat of the same oil used originally. Allow to cure fully before use.
Can tung oil be applied over linseed oil?
It is generally not advisable to apply tung oil over a linseed oil finish. To switch oils, the previous finish must be completely stripped first for proper adhesion and curing. Tung oil can be applied over cured varnish or shellac finishes.
Conclusion
Tung oil and linseed oil are both classic, natural finishes that enhance wood beautifully. For surfaces that demand supreme toughness and water resistance like floors and furniture, tung oil is the clear winner. It dries fast to a durable, flexible film. Linseed oil is more budget-friendly for large indoor projects where durability is less critical. Consider the costs, benefits, and project specifics when choosing between these two iconic wood finishing oils. Apply either oil properly following safety precautions, and you can obtain years of protection and enjoyment from your wood projects.