How to varnish a wooden surface so that there are no bubbles
Good afternoon. Bubbles appear on the surface. The varnish is three-component, we cover the floor. Tool velor roller. Tried with a brush, no bubbles, the floor shines better. Gloss varnish PTL 500. Hardener and thinner from this varnish series. We use a roller for varnishes. Advise what is better to paint and that there are no bubbles. Airbrush?
Albert
Expert Answer
Good afternoon, Albert!
Small bubbles appearing on the painted wooden surface indicate that the varnish foams when applied - this often leads to multicomponent decorative compositions. At the same time, defective places often become so rough and unsightly that they require repeated application of the varnish coating after grinding.
There are several reasons for this kind of trouble:
The varnish was prepared in violation of technology. Multicomponent polyurethane compositions require mixing in proportions and with the conditions specified by the manufacturer. You should definitely look at the date of manufacture and expiration date - if the storage conditions are violated, the decorative coating loses its quality.
The PTL500 varnish of your choice is thixotropic, that is, those that thicken at rest, and when agitated, regain excellent fluidity. The flip side of this process is the saturation of the mixture with air, which when applied is released in the form of small bubbles. Such a phenomenon can only be avoided if the varnish is applied using a spray gun (which, however, is exactly what the manufacturer recommends) or with a paint brush. In the latter case, the appearance of bubbles can be easily eliminated by translational movements. Simply put, your chosen method of dyeing with a roller, even if of the highest quality, velor, is not suitable in this case.
Mixing the components during preparation of the PTL500 thixotropic gloss varnish results in foaming of the mixture. You should not start painting the floor immediately after the hardener, diluent and base have been bonded - you must wait until the resulting foam settles. Otherwise, the bubbles that form it will transfer to the surface to be painted.
In order to avoid the appearance of bubbles, check for deviations in the technology of preparing the coloring composition and be sure to adhere to the technology of its application. Having eliminated all the factors contributing to the foaming of the varnish, you will get a floor that is evenly painted, sparkling with a glossy gloss.
