Outdoor wood furniture can add beauty and warmth to your patio, deck, or backyard. However, without proper care and maintenance, it can quickly become weathered, warped, cracked, or discolored. Sealing outdoor wood furniture is an essential step to protect it from the elements and make it last for years. This comprehensive guide will provide you with everything you need to know about sealing outdoor wood furniture.
Why Seal Outdoor Wood Furniture?
Sealing outdoor wood furniture provides a protective barrier against moisture, ultraviolet (UV) rays from the sun, insects, mold, and mildew. Here are some of the key benefits of sealing outdoor wood furniture:
- Prevents Cracking and Warping: Unsealed wood exposed to repeated wetting and drying can crack, warp, and split over time. Sealer penetrates the wood grain to make it weather-resistant.
- Minimizes Discoloration: Wood sealers with UV inhibitors help prevent graying and bleaching from constant sun exposure. This helps maintain the rich color of the wood.
- Repels Water: Sealers make wood impervious to moisture, preventing water saturation and damage.
- Resists Mold and Mildew: Sealers deny moisture to mold and mildew spores. This prevents staining, decomposition, and foul odors.
- Deters Wood-Boring Insects: Insects are repelled by protective sealers since they cannot easily penetrate the wood surface.
- Prolongs Furniture Lifespan: Overall, sealing shields wood from deterioration, helping furniture last 2-3 times longer.
Regular sealing is vital for all outdoor wood furniture, whether store-bought or homemade. It protects your investment from irreparable damage.
What Type of Wood Needs Sealing?
All outdoor wood furniture and structures require protective sealing, though some wood types need it more than others:
Softwoods
Softwoods like pine, cedar, redwood, and cypress have a lower density with wider wood grains. They absorb more moisture and deteriorate faster. Annual sealing is recommended for:
- Pine
- Cedar
- Redwood
- Cypress
- Fir
- Spruce
Hardwoods
Denser hardwoods like teak, ipe, and mahogany have natural oils that make them more resistant to weathering. However, sealing is still required every 2-3 years for:
- Teak
- Ipe
- Mahogany
- Eucalyptus
- Walnut
- Oak
Engineered Woods
Engineered woods like plywood, particleboard, and MDF are very porous. They can swell, delaminate, or decompose quickly without adequate sealing. Seal them every 6 months to 1 year.
Regardless of wood type, new furniture without factory-applied sealers needs immediate sealing. Also, assess older wood pieces annually and refinish worn surfaces that expose unsealed wood.
When to Seal Outdoor Wood Furniture
Sealing outdoor wood furniture is largely dependent on weather and climate:
New Wood Furniture
- Seal immediately to prevent surface damage during storage or transportation.
Change of Season
- Spring – Seal stripped furniture and recoat worn surfaces after winter exposure.
- Fall – Apply fresh sealer before furniture storage for winter.
Routine Maintenance
- Every 1-3 years for hardwoods like teak and mahogany.
- Every 6-12 months for softwoods like pine and cedar.
- Every 6 months to 1 year for engineered woods.
After Cleaning or Refinishing
- Seal again after intensive processes like stripping, sanding, staining, or varnishing.
Relocation
- Seal wood moving to a new home with a different climate.
Monitor your furniture and local weather patterns. Adjust sealing frequency based on wear. Immediately refinish damaged areas.
How to Prepare Wood Before Sealing
Proper preparation is key for the sealer to adhere well and provide optimal protection:
Clean thoroughly
Use a stiff brush and mild detergent to remove dirt, grime, residue, mold, and mildew. Rinse well and let dry completely.
Sand lightly
Sand with 180-220 grit sandpaper to smoothen and prep the surface. Always sand along the wood grain.
Remove old sealer
Strip off flaking or peeling sealer with chemical strippers or sandpapers. This prevents lifting or delamination.
Eliminate stains/discoloration
Bleach and oxalic acid can remove graying, mildew stains, and water marks. Rinse after treatment.
Repair imperfections
Fill cracks, holes, and splits with appropriate wood fillers. Allow proper drying time.
Allow to dry
Wood must be absolutely dry before sealing. Moisture prevents absorption.
Proper prep allows for uniform sealing and maximum adherence. It also enhances the final look.
Types of Sealers for Outdoor Wood Furniture
There are many sealer options specially formulated for exterior wood:
Oil-Based Sealers
- Tung Oil – Provides a rich patina on hardwoods. Requires multiple coats.
- Linseed Oil – Economical option derived from flaxseed. Has a strong odor.
- Penetrating Oils – Contain oils, resins, and mildewcides. Offer minimal protection.
- Teak Oil – Penetrates dense teak while enhancing its golden hue. Requires frequent reapplication.
- Marine Spar Varnish – Provides a glossy coating with UV protection. Ideal for boats and outdoor furniture.
Water-Based Sealers
- Water-Repellent Sealers – Contain waxes/oils to repel water. Offer short-term protection.
- Water-Based Polyurethane – Acrylic versions provide UV resistance without yellowing over time.
- Water-Based Spar Urethane – Offers a clear, protective finish similar to traditional varnish. Low odor and fast drying.
Lacquer Sealers
- Marine-Grade Spar Lacquer – Dries into a hard, glossy finish that resists cracking, peeling and moisture.
- Exterior Acrylic Lacquer – Satin or glossy finish. More fade and scratch-resistant than varnish.
Epoxy Resin
- Two-Part Epoxy – Seals wood pores completely. Use for heavily damaged furniture. Gives a plastic-like finish.
Consider oil-based for hardwoods, epoxy for rot repair, and water-based for easy application. Read labels to pick the best sealer for your particular wood type and finish.
How to Apply Wood Sealer
Here is a step-by-step guide to applying sealers for flawless results:
1. Prepare the Wood Surface
Follow the cleaning, sanding, stripping, and repair steps mentioned in the preparation section. The surface must be pristine before sealing.
2. Read Product Instructions
Read the manufacturer’s instructions for application directions, dry times, recoat times, and any precautions.
3. Choose an Outdoor Work Area
Pick a shaded spot away from direct sunlight. Sunlight and heat can cause the sealer to dry too fast. Work in dry, wind-free conditions.
4. Stir the Sealer
Stir the sealer thoroughly before and during use. This mixes the ingredients evenly.
5. Apply a Sealant Pad
Adhere pliant sealant pads on table bottoms and chair legs. This prevents sticking to deck or patio surfaces.
6. Wear Protective Gear
Use gloves, eye protection, and an appropriate mask to avoid exposure hazards from fumes.
7. Use a Natural Bristle Brush
A high-quality natural bristle brush holds sufficient sealer and releases it evenly onto wood. Disposable foam brushes don’t work as well for smoothing and brush strokes.
8. Apply Along the Wood Grain
Use smooth, thin, even strokes along the length of the wood grain – not across. This maintains the wood’s natural appearance.
9. Maintain a Wet Edge
Overlap coating passes to keep a wet edge for uniform adhesion within sections. Work from one end of the furniture to the other.
10. Coat All Surfaces
Seal all exterior surfaces – front, back, sides, and bottom. Don’t forget crevices and joints.
11. Allow Proper Dry Time
Let the piece dry adequately between coats as per manufacturer’s directions. Insufficient drying impairs absorption and curing.
12. Apply Multiple Coats
For optimal protection, apply at least 2-3 thin coats for penetrating oils and 3-4 for film-forming sealers like varnish or lacquer.
13. Clean Equipment Promptly
Clean brushes and other tools in appropriate solvents like paint thinner right after use. Don’t let sealer residue dry on them.
With the right tools, ventilation, and technique, you can easily get a professional-looking, long-lasting wood sealer finish.
How to Maintain and Repair Sealed Wood Furniture
To make your sealed outdoor wood furniture last for years, incorporate these care and maintenance practices:
- Inspect furniture periodically for wear, cracks, peeling, discoloration, mold, etc. Refinish affected areas promptly.
- Clean regularly with a mild detergent and soft brush. Avoid harsh cleaners or abrasives.
- Move/cover furniture during construction or renovations to avoid damage from debris.
- Use furniture coasters and tablecloths to prevent hot items from causing sealer damage.
- Keep wood hydrated with approved products like teak oil. This prevents drying and splits.
- Sand lightly and recoat with sealer every year as needed to reinforce worn surfaces.
- For deep cleaning, use a sealer-safe deck cleaner and brightener. Rinse off completely.
- Replace broken hardware like screws, dowels, and handles that compromise structural integrity.
- Make repairs ASAP to prevent moisture ingress and greater damage. Use appropriate color-matched wood fillers for cracks and holes.
- If the finish starts heavily deteriorating, fully strip the existing sealer and start over.
With timely repairs and refinishing, your sealed outdoor wood furniture can serve you season after season.
FAQs About Sealing Outdoor Wood Furniture
What is the best sealer for outdoor wood furniture?
For outdoor use, marine-grade spar varnish, tung oil, and water-based polyurethane provide the best protection against water, sun, and moisture damage. Opt for oil-based sealers for hardwoods and water-based for softwoods.
How long does wood sealer last outdoors?
On outdoor wood furniture, most sealers last 1-3 years before needing renewal. Softwoods and engineered woods require more frequent sealing than dense hardwoods. Climate, exposure, and usage impact sealer lifespan.
Can you use indoor sealer outdoors?
Sealers formulated specifically for exterior use stand up much better outdoors. Interior polyurethanes and varnishes lack the UV inhibitors and water resistance needed for outdoor furniture.
What are the signs that wood furniture needs resealing?
Look for a faded milky appearance, peeling, flaking, cracking, splintering, bleaching, discoloration, spots from water beads, mold or mildew growth etc. These indicate the protective seal has worn off.
How long should sealed wood dry before recoating?
Oil-based sealers require 72 hours minimum between coats. Water-based types need 2-4 hours drying. Always follow manufacturer directions for recoat times. Insufficient drying affects adhesion.
Can you apply sealer over old sealer?
Yes, sealers can be applied over existing coats that are cleaned, lightly sanded and structurally sound. Removing all old sealer is needed only if it is extensively damaged, peeled, or flaking.
How do you remove sealer from outdoor wood furniture?
Use chemical strippers to dissolve the layers of sealant and remove it. Refinishing products like Interlux Interstrip work well for thorough stripping before resealing.
Why does my sealed furniture turn white?
White spots and hazy areas on varnished wood are caused by moisture condensation getting under the finish. This is called blushing. Refinishing is needed to restore its clarity.
Sealing outdoor wood furniture properly helps it withstand the elements year after year. Follow these comprehensive tips to protect your valued furniture.
Conclusion
Outdoor wood furniture graces many houses with its beauty, but without proper sealing it is vulnerable to environmental damage. Sealing creates a protective barrier against the effects of moisture, sun, pests, and time. This comprehensive guide covers why and how to seal outdoor wood furniture for longevity and enjoyment.
We have provided key information on ideal sealing timelines, recommended products for different wood types, surface prep, application techniques, drying times, maintenance, repairs, and more. Invest wisely in high quality sealers like marine spar varnish and tung oil. Apply multiple layers along the wood grain after thorough cleaning and light sanding. Inspect and recoat as needed every year or few years based on wear and wood type. Address any damage quickly.
With diligent sealing and care, your outdoor wood furniture can thrive outdoors for decades, becoming even more gorgeous as years pass. Use these tips to defend and extend the life of your cherished wood pieces. Let your outdoor wooden furniture glow with health for generations to come!