It is similar tovarnish, shellac, and lacquer, except that polyurethane is polymer-based.
Oil-based polyurethane is self-leveling, which means that it will become smooth when applied to a horizontal surface.
Appearance
Water-based polyurethane begins milky-white in the can but dries clear.
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Very little, if any, color is imparted by the water-based polyurethane.
One or two coats apply nearly invisible and with almost no build.
It’s not unusual to use four to eight coats of water-based polyurethane.
Oil-based polyurethane coatings achieve a rich, golden glow in few coats.
Durability and Maintenance
Water-based polyurethane tends to be less durable than oil-based products.
Water-based polyurethane scratches and dents easily.
Oil-based polyurethane coatings provide excellent abrasion and scratch resistance.
program
Water-based polyurethane can be applied with a brush, roller, spray, or rag.
The smell is not noxious, though it’s always a good idea to ventilate the room.
Because water-based polyurethane is so thin, it can be challenging to see where you have applied the product.
Oil-based polyurethane can be applied with a brush, roller, spray, or rag.
During tool, the odor is sharp and pronounced, and many people find it objectionable.
By the time the product has fully cured, the odor will have gone away.
Tip
Applying polyurethane by spraying it is the best way to ensure even, professional-looking results.
Drying and Recoat Time
Water-based polyurethane dries and cures fast.
This allows for faster program of multiple coats compared to oil-based polyurethane.
Oil-based polyurethane dries and cures slowly.
One coat dries to the touch in two to three hours.
Recoat time for oil-based polyurethane can be up to 12 hours.
Clean-Up
Water-based polyurethane coatings require only soap and water to clean off hands or tools.
Oil-based polyurethane requires mineral spirits or paint thinner for cleanup.
How to Choose
Water-based and oil-based polyurethanes are not mutually exclusive.
Wherever you use water-based polyurethane, you might also use oil-based polyurethane.
Water-based polyurethane is easy to apply and clean up after.
Water-based polyurethane should be your choice if you are averse to dealing with messy, odorous solvents.
Typical uses for oil-based polyurethane include:
You should sand between coats of polyurethane.
Sanding between coats of polyurethane ensures a smoother finish.
Be sure to wait the full recoat time before reapplying the polyurethane finish.
With oil-based polyurethane, you should apply one or two coats.
With water-based polyurethane, you may need to apply as many as four to eight coats.
Wear a NIOSH-approved P-95 respirator mask when applying oil-based polyurethane.
The area should also be well-ventilated.
A respirator mask is usually not necessary when applying water-based polyurethane.
