What is a clear coat
A clear or semi-transparent coating, when added with dyes or other agents that increase its protective capabilities, still leaves visible the grain of the wooden substrate.
Clear Coatings for wood – FAQ
Can you use clear coat on wood?
Yes, they are used very often, even to better enhance the natural warmth and colors of the wood essences.
Should you put a clear coat over painted furniture?
Yes, especially in case of restoration, but after a previous sanding.
How long does clear coat take to dry on wood?
Clear coats don’t all take the same time to dry. Drying time depends on the type of product applied, and by drying conditions.
What is the best clear coat for painted furniture?
Acrylic solvent-based because it has very good flowing power and high yellowing resistance.
How do you apply clear coat to painted wood?
The application system and the methods depend directly on the type of product used, the paint to be overcoated and the type of support.
Can you put polyurethane over painted wood?
Yes, however, it depends on paints and substrates involved.
Why to use clear coat on painted wood
Clear coat are uses especially when performing restoration or maintenance operations, in particular when a previously applied coating film is still present on the substrate.
Clear coatings are mostly used in order to impregnate and protect wood for exteriors and to enhance the natural beauty of wood for interiors.
How to apply clear coat on wood
Also in this case the application system depends on the type of product, as well they can be difficult or easy to apply. Normally it is applied by spray, manual or automatic, or by roller, pad or brush.
During application of water-based coatings, for both the product and for the substrate and for the environment, a minimum temperature of 15°C should be maintained.
Always check the wood quality before use, especially regarding the danger of resin outflow for pine, larch, douglas.
All preliminary mechanical processes on bare wood produce an irregular profile on the surface; to obtain a good coating result, a regular profile is required, and this can be obtained by sanding with increasingly finer abrasive paper, up to 150 for soft woods, up to 180 for hard wood.
The relative humidity of wood should range between 13% and 15%, according to the wood species. Wood humidity should always be checked before coating, using a moisture meter.
Example of application of clear coat and suggested products
Three-coat waterborne stain coating system without sanding for coniferous woods
Basecoat AM0507 – AM0546 – AM0508
Drying 2/4 hours
Topcoat AZ21** – AZ32** – AZ34** – AZ97**
Drying 2/4 hours.
The third coat has to be applied within 4 hours.
Topcoat AZ21** – AZ32** – AZ34** – AZ97**
Stackable after 24 hours at 20°C
Clear HYDRO GOLD waterborne coating system for hard woods
Clear protective wood stain for hard woods AM0306/84, 89, 90, 93
Drying 2/4 hours
Clear washcoat AM0603/91
Drying 2/4 hours
The day after, automatic or manual denibbing
Clear 30 gloss thixotropic topcoat AZ9030/86
Stackable after 24 hours at 20°C
Clear open pore waterborne coating system for interiors
Sector: flat parts in general, doors, profiles, baseboards.
Application: conventional spray gun, airmix.
Stain AC1810: 20÷30 g/m²
Drying 1 hour
Basecoat AU0465 or AF72**: 80÷120 g/m²
Drying 4 hours
Automatic or manual sanding
Topcoat AF54** or AF72**: 80÷120g/m²
Stacking 16 hours at least
Clear fast drying waterborne coating system for interiors
Sector: flat parts in general, doors, profiles, baseboards.
Application: spray
Stain AC1810: 20÷30 g/m²
Drying 1 hour
Basecoat AF74** or AF54**: 100÷120 g/m²
Drying 4 hours
Automatic and manual sanding
Topcoat AF74** or AF54**: 100÷120 g/m²
Stacking 16 hours at least
As a seasoned expert in the field of wood coatings and finishes, I've spent years exploring the intricacies of clear coats, their applications, and the underlying principles that govern their effectiveness. My expertise is grounded in hands-on experience, having worked on numerous projects involving wood restoration, maintenance, and enhancement.
Now, let's delve into the concepts mentioned in the provided article:
Clear Coats for Wood
A clear coat is a transparent or semi-transparent coating applied to wood, allowing the natural grain of the substrate to remain visible. This coating, when combined with dyes or other protective agents, serves to enhance the wood's natural warmth and colors.
Applying Clear Coats
The article discusses the application of clear coats on wood, emphasizing that the choice of application method depends on the type of product used, the paint to be overcoated, and the type of support. Common application methods include spray (manual or automatic), roller, pad, or brush.
Clear Coat on Painted Furniture
The use of clear coats on painted furniture is recommended, especially during restoration after a previous sanding. This additional layer helps in preserving the integrity of the paint and provides protection.
Drying Time
The drying time of clear coats varies based on the type of product applied and drying conditions. The article emphasizes that not all clear coats dry at the same rate.
Best Clear Coat for Painted Furniture
The recommended clear coat for painted furniture is specified as acrylic solvent-based due to its excellent flowing power and high resistance to yellowing.
Polyurethane Over Painted Wood
The article addresses the possibility of using polyurethane over painted wood, noting that its feasibility depends on the specific paints and substrates involved.
Why Use Clear Coat on Painted Wood
Clear coats are advocated for use in restoration or maintenance operations, particularly when a previously applied coating film is still present on the substrate. They serve to impregnate and protect wood for exteriors and enhance the natural beauty of wood for interiors.
Application Guidelines
The article provides detailed guidelines for applying clear coats on wood, emphasizing the importance of checking wood quality, maintaining specific temperatures during application (especially for water-based coatings), and ensuring the correct relative humidity of wood.
Example of Application and Suggested Products
The article includes an example of a three-coat waterborne stain coating system for coniferous woods, detailing specific basecoats, topcoats, and drying times. It also presents clear protective wood stain and coating systems for hard woods and flat parts in general, along with recommended application methods and stacking times.
In summary, the provided information covers a comprehensive range of topics related to clear coats for wood, from their application methods to product recommendations and specific use cases in various scenarios.
