Varnishes vs Sealers – Why Environmentally Friendly Water-Based Sealers Make Sense

When it comes to protecting wood, the choice between varnish and sealer is important — but the bigger decision is what type of sealer you use. If you’re aiming for durability, easier application, and a finish that’s environmentally friendly, water-based sealers have clear advantages over solvent-based sealers.

Solvent-based sealers use petrochemical solvents that release high levels of volatile organic compounds (VOCs) into the air. These VOCs contribute to poor indoor air quality, are linked to health issues, and add to environmental pollution. They often have a strong odour and require harsh chemicals for brush and tool cleaning.

Water-based sealers, by contrast, use water as the primary carrier. This means:

Low VOC content – better for the environment and safer indoors.

Low odour – more pleasant to use for indoor wood projects.

Easy cleanup – warm, soapy water is all you need.

These qualities make water-based sealers the go-to choice for anyone looking for a non-toxic wood finish that’s safer for both people and the planet.

Wood isn’t static. It expands and contracts naturally with changes in moisture and temperature. This movement can put any coating under strain.

An oil-based sealer cures to a very hard, rigid film. It looks good at first, but over time, when the wood moves, that brittle coating can crack — especially at joints and edges. Once cracked, water can get in, and rot can develop under the surface.

A water-based sealer cures to a hard but slightly more elastic film. It completely seals the wood from moisture penetration, but retains enough flexibility to accommodate natural wood movement. This helps prevent cracks from forming, keeping the protective layer intact and extending the life of the wood.

Another advantage of water-based sealers is that they stay clear wood sealers — they don’t amber or yellow with age. This means lighter timbers keep their original colour. In contrast, many oil-based coatings will yellow over time, altering the appearance.

For exterior wood, choosing a UV protection sealer will help maintain colour and resist sun damage, without relying on the high solvent levels of traditional products.

If you want a finish that’s durable, environmentally friendly, and designed to handle wood’s natural movement, a high-quality water-based sealer is the smart choice. You’ll avoid the VOC emissions, strong odours, and brittleness of solvent-based sealers, while still getting long-lasting protection.

Harlequin’s range of water-based sealers delivers professional-grade results — whether you’re sealing indoor furniture, exterior wood, or decorative joinery — with an eco-conscious approach.