Overcoat old synthetic resin paint with the same type of paint

The overpainting of old or fully dried synthetic resin paint is possible without any problems. In order to achieve optimum coverage and uniformity, solvent-based synthetic resin paint should again be used. Water based acrylic paints can get in some difficulties with the opacity and durability.

Grinding is usually enough

In general, overcoating is ideally done with the same type of paint that makes up the existing paint. When in doubt, a synthetic resin paint for overcoating is always a safe bet. Dried and cured old synthetic resin paint can be treated like a plastic layer.

The mechanical roughening with abrasives of the grit sizes 200 and 300 forms the hold that the new varnish layer needs. Fat and dust must be given in addition. Lots of old paint residue and exfoliation must be completely removed. Should the ground, such as wood, be exposed in places, the different absorbency must be counteracted.

Sand all surfaces

In order to be sure of the order, the old synthetic resin varnish should be pretreated with a primer or primer. However, if the old synthetic resin varnish is in perfect condition in the distribution on the varnished surface, pretreatment can be dispensed with and the new synthetic resin varnish applied directly.

When sanding the old paint surface, any bumps and any traces of scratching should be leveled. Profiles, inlays, trims and cassettes must also be processed by hand along the edges, depressions and corners. Caution is required for door leaves whose inserts or cassettes are made of thin wood and can be easily crushed during grinding.

Always try water-based acrylic paints first

If water-based acrylic lacquers are to be applied to the synthetic resin lacquer, a sample lacquering must prove the opacity. In this case always work with a primer or a primer.

Concerning the opacity there are natural limits. When light acrylic varnishes are applied to dark pre-varnished old paints, a shadowless new paint is not always possible. With renewed use of synthetic resin paint even very dark pre-paintings can be thoroughly covered.

Tips & Tricks

If you want to switch to acrylic paint, especially for environmental reasons, you should completely free wooden doors and windows from the old synthetic resin paint. Only then can water-based glazes and paints play to their advantages and strengths.

Video Board: How to Varnish an Acrylic Painting