What are the key points for applying varnish correctly?
The application of a varnish is an important step in the successful realization of a waxed concrete. This is what will determine the quality of your waxed concrete's protection and facilitate its daily maintenance.
1/ Matt, satin or gloss?
The first step is to choose the look of your varnish: most are available in matte, silk matte, satin or gloss. Most work is done in silk-matte or satin-matte, as this retains a certain depth of material, while giving a pleasing finish to the eye.
Shiny finishes, on the other hand, are rarely used with mineral materials, as they give a somewhat flashy surface appearance. However, gloss goes well with black, for example, or red, to give a lacquered effect.
Finally, matte varnish gives depth to materials and a very contemporary raw look. It is particularly well-suited to walls, to give them depth in relation to the light.
2/ Once the look has been determined, how do you choose the right varnish from the Marius Aurenti range?
For wall protection, we recommend our single-component acrylic wall varnish. Simple and effective, it's applied with a roller, using criss-cross strokes. It provides sufficient protection against accidental splashes, and can be washed off the wall for regular cleaning.
In high-traffic areas, two-component, polyurethane-based HR1 and n°7 Visco varnishes are the ideal choice. They include a base and a hardener. Marius Aurenti develops water-based varnishes, but for high-traffic areas such as kitchens, bathrooms and high-traffic floors, professionals use our range of solvent-based varnishes. These increase mechanical strength and resistance to chemical agents, and guarantee ease of cleaning and longer life.
3/ How much varnish should I use?
Once you've decided on the effect - matt, satin or gloss - and the type of varnish to use, you need to calculate the quantity of varnish you'll need for your job. If, for example, you need to cover a 50 m² floor and the varnish is quoted at 250 g per square meter, you'll need 12.5 kg of varnish. It's important to use up all 12.5 kg of varnish, adapting the number of coats you repeat until the quantity is used up. It's the quantity, and the quantity alone, that determines the quality of the protection!
Regarding application, avoid applying very thick coats. They won't stretch very well and won't form the film needed to protect your work.
It is therefore preferable to apply more thin coats than fewer thick ones. In addition, each varnish requires a specific drying time between coats. This time must be respected to ensure that the new coat doesn't melt or technically soak the previous coat by depositing it too hastily.
4/ Good site conditions
On a building site, the temperature and humidity of the air and substrate are crucial. In fact, if you apply your varnish on concrete If the concrete is still wet, the film will mix with the water and, once dry, won't play its role of stain protection. It is therefore important to allow the concrete to dry, ideally 48 hours at 20° C, before applying the varnish.
Temperature also influences humidity, as it determines the speed at which the varnish sets. Ideally, therefore, you should work two days after applying your concrete at a temperature of 20° and humidity conditions of 65 %. If these conditions are not met on your site, you can use a heating or dehumidification system if necessary.
5/ Preparing the varnish
In the case of two-component varnishes, preparation must respect the mix between component A and component B, as indicated on the packaging. A scale is therefore required to prepare your mixture for a single coat. Note that solvent-based varnishes require a thin first coat with a longer drying time, generally overnight, to allow the concrete pores to be thoroughly sealed. Water-based polyurethane varnishes, on the other hand, may require prior application of a pore filler.
Repeat for each coat of varnish. If any varnish remains after one coat, do not save it for the next, as it will have lost its stain-resistant quality.
6/ Applying varnish
When using solvent-based varnishes, make sure you have the necessary protective equipment and a special mask.
Two-component varnishes, such as HR1 or n°7 Visco, require the hardener to be thoroughly mixed with the base to ensure correct reaction. Allow to stand for five minutes before application, and stir again before starting.
Before applying the first coat, it's important to remove dust from the substrate with a vacuum cleaner, and to ensure that your worksite is dust-free between coats.
Start by applying to edges and corners using a brush or small microfiber roller. Then, for larger surfaces, use a 10 mm microfiber roller, criss-crossing the coats. You can lightly sand with 240 grit paper between coats, if necessary.
Once the varnish has been applied, the surface dries very quickly. It can usually be walked on with protective footwear the next day, but will not have finished drying.
Traffic is possible after three days, and a varnished surface can be made wet after 7 days at 20° temperature and 65 % humidity.
7/ Varnishes tested and approved for over 35 years
Marius Aurenti varnishes are recognized by professionals, and have been used for over 35 years in public buildings, residential settings and intensive-use establishments. They are extremely resistant and require very little renovation, given their solidity. A good regular cleaning system ensures their longevity, and they can also be polished with sanding tools in the event of micro-scratches.
If, after several years, you wish to renovate your surface, you can do so by lightly sanding it with 120-grit sandpaper after stripping, and renewing one to three coats of varnish if necessary. One last point: check that varnishes are fresh and can be stored in frost-free and heat-resistant conditions.
Good application, your job is almost done!