Polyurethane varnish for wood can be used on doors, window frames, floors and other joinery structures. Providing a tough finish, they are great for protecting wood against abrasive scuffs, knocks and scratches. So, if you are looking for more a durable and protective wood finish than wood oils offer, for bare woods or previously stained/varnished surfaces, Rawlins Paints have a great selection of polyurethane varnishes from Blackfriar, Coo-Var, Jotun and Mathys.
Don’t forget that Rawlins Paints also stock a wide range of fire retardant varnishes for wood, should you require improved fire protection at your work premises or commercial/private property. These coatings will maintain the look of timber surfaces, whilst providing up-to 60 minutes’ fire resistance.
- What is Polyurethane Varnish?
- Polyurethane Varnishes at Rawlins Paints
- Technical Support. 12
Polyurethane varnishes are super-tough ‘coatings’ popularly used as a finishing layer for protecting interior and exterior wooden floors, stairs and other surfaces prone to pedestrian wear and tear – some products can also be used on chipboard, plywood, hardboard, and parquet surfaces. Easy to use, with water-based polyurethane varnishes containing lower VOCs than solvent or oil based versions, and more durable than standard wood varnishes, they are a popular choice for woodworkers, furniture makers and restorers, and joiners. From floors to cabinets, and stairs to bar surfaces, polyurethane varnishes can deliver excellent protective qualities in gloss, matt or satin finishes.
A polyurethane finish can best be described as a hardening liquid plastic coating. Frequently used in renovation, restoration and repair work within libraries, hotels, restaurants, bars, cafes and independent boutique retail shops, the finished coat is designed to provide long-lasting, durable and hard-wearing protection.
Today, water-based polyurethane varnishes differ from older production of varnishes, in that they produce lower VOCs than resins, oils and solvents previously used. Many manufacturers produce clear polyurethane varnishes, but they are also available in the following tints and shades:
- Antique Pine
- Light Oak
- Medium Oak
- Dark Oak
- Golden Oak
- Dark Mahogany
- Spanish Mahogany
- Deep Red Mahogany
- Golden Teak
- Burmese Teak
- Dark Jacobean
Although labelled as a clear polyurethane varnish, as with any varnish, the finished effect depends on the type of wood it is applied to – with some darkening the wood grain.
- Solvent and oil-based polyurethane varnishes can dry to leave a slightly amber finish, warming up the wood and its grain. Being slower to dry than the water-based products, it of course means that there needs to be longer periods of time left between additional coats.
- These products contain higher VOCs, and application equipment requires cleaning up with solvent.
- Water-based polyurethane varnishes have a milky tint in colour, but will dry to leave a clearer, more transparent finish than solvent-based products – preferable to some users.
- Application equipment for water based polyurethane varnishes can be cleaned-up with soap and water – always refer to product datasheets for manufacturer specific recommendations for cleaning and storage.
The choice of finishes available – gloss, matt and satin – typically rely on user preference.
Solvent and oil-based polyurethane varnishes are stronger and more durable than water-based ones, with products stocked at Rawlins Paints focusing on commercial and trade usage on floors and within hospitality sector, rather than domestic and DIY projects.
There are alternatives to polyurethane varnishes for use within the marine sector and for wooden surfaces that are required to be fire retardant.
Polyurethane that is used in floor varnishes, for example, are water or solvent based plastic resin coatings, typically clear, that deliver a specific finish on wood – this differs from other types of polyurethane application use, including flexible/rigid polyurethane foam, thermoplastic polyurethane (TPU), reaction injection molding (RIM), and other automotive, electronic, medical or packaging varieties.
Most wood finishes penetrate the wood surface and soak into the substrate, including some varnishes. Polyurethane wood varnish dries on top of the surface, protecting it with an anti-abrasive sealed layer. Primarily clear/translucent/transparent ‘topcoats’, polyurethane varnishes:
- Dry quicker than standard wood varnishes
- Contain a water or solvent-based plastic resin, compared to standard varnishes containing resins, oils and solvents
- Can be applied by brush, spray or roller. Traditional varnishes, in comparison, are usually brush applied only.
- Are more durable than traditional wood varnishes.
- Protect wood surfaces – floors, desks, furniture, counter-tops, etc. – for longer than standard wood varnishes, and as such are slightly more expensive than the economically priced counterparts
Keep an eye out for an upcoming article on single and two-pack polyurethane paints and coatings available at Rawlins Paints, from manufacturers including Sikafloor, Teamac, Nullifire and Rust-Oleum.
Blackfriar Heavy Duty Varnish is an odourless, two pack water-based polyurethane varnish, primarily designed for wooden floors – but can be used on bar tops, furniture or concrete floors. Delivering a highly durable, non-yellowing and chemically resistant finish, it also resists boiling water, alcohol, coffee, red wine and dilute acid and alkalis.
- Touch dry – 2 hours (20°C)
- Hard dry – 8 hours (20°C)
- Full cure – 3 days (20°C)
- Recoatable after 4 hours
Blackfriar Polyurethane Floor Varnish is primarily designed for use on wooden floors, but can also be used on doors, wood panelling and other joinery applications. For interior use only, it delivers excellent protection against knocks and stains, dilute acids and alkalis.
Available as a gloss or satin, and applicable by brush, roller or spray, Blackfriar Polyurethane Floor Varnish is touch dry in 2-4 hours, and recoatable after 16 hours – under normal conditions.
As with all wood varnishes, ensure that the substrate that is to be varnished is sound and free from any surface contaminant likely to cause adhesion problems – e.g. wax, grease, polish, etc. Always degrease previously wax polished floors prior to sanding and applying the polyurethane varnish.
Blackfriar Polyurethane Varnish is a tough and durable matt, silk or gloss coating that will bring out the natural grain and colours of wooden surfaces. Transforming interior woodwork, with a variety of wood colours and shades available, it offers great protection against common stains, including hot water damage from spills and splashes.
Suitable for all types of interior woods, the matt finish option is not suitable for use on floors, nor should it be used over French polished surfaces.
Please note that the final shade of the applied varnish will depend upon the original colour and absorption of the wood or timber. It is recommended to test for shade on an off-cut or inconspicuous area. When using two tins, it is recommended mixing them, to ensure an even shade is obtained.
The product may be applied by brush or roller. If applying by brush, apply evenly using light strokes following the grain of the wood. If applying by roller, use a short nap mohair roller. For best results 3-4 coats are recommended on new wood and 2-3 coats on previously varnished surfaces. Prior to application of the final coat or if the overcoating time is exceeded lightly abrade with fine glass paper working with the grain and remove dust.
Coo-Var P101 2 Pack Polyurethane Varnish is a clear aliphatic polyurethane coating which provides a hard-wearing protective coating for internal or external wooden floors which regularly undergo heavy foot traffic. It is ideal for gymnasiums, dance floors and performing arts studios.
The product is supplied in two containers: one larger than the other and labelled Base. The other smaller one labelled Hardener. The contents of the pack marked Hardener are added to the contents of the larger pack marked Base and thoroughly mixed together, preferably by slow speed electric mixer for 2 minutes or until thoroughly mixed. Failure to mix the material correctly will lead to uncured areas in the coating.
Polyurethane varnish is a single pack product of exceptional durability based on urethane alkyd. It is intended for interior use only, on restaurant, café and kitchen worktops, and internal doors.
Available in gloss, matt and eggshell varnish finishes, this clear coating can also be used on smaller floor surface areas.
Coo-Var Polyurethane Clear Floor Coating delivers an economical gloss, eggshell or matt finish to most wooden floors. This single pack, clear floor varnish, is oil-based and dries to a hard glaze, which is easy to clean in busy areas – such as classrooms, meeting rooms, etc.
Rust-Oleum 4900 Polycoat 2K is a clear, water-based, 2-component polyurethane topcoat for use on wood, concrete and pre-painted surfaces, also serves as an anti-graffiti coating. Very abrasion resistant, available in a matt or gloss finish, does not yellow, can be used internally and externally, resists boiling water, alcohol, coffee, red wine, dilute acid and alkalis.
- Clear varnish for parquet to protect against stains and scratches
- Clear sealer for concrete to decrease dusting and increase cleanability
- As an anti-graffiti coating
- As a topcoat on previously painted surfaces to provide extra protection and/or change gloss level
If you require any further information than that covered in this article, please leave a comment below, or contact Rawlins Paints’ technical support team.