10 most common mistakes by Marmorino Venetian Plaster applicators
There are two kinds of Marmorino Venetian Plaster available on the Market:
Marmorino Fine and Grained Marmorino. Applying Marmorino Fine is usually the same as any fine Venetian Plaster: 3 coats of the same material with compressing and polishing in the end.
However, Grained Marmorino (like Calcherra Marmorino by Fresco or Coarse Marmorino by Rivesto) is an entirely different process.
We recommend the so called “two and half” coats process: primer, first coat, next day – second coat and additional wet on wet take off, compressing and polishing. See below for the most common mistakes by Marmorino applicators:
Using regular Latex or Oil base primer will lead to excessive working time when applying the first coat (the material is not going to hold onto primed surface as you apply it and you would have to manipulate with the trowel much longer to get the right result). And in the end the finish could peel off the wall.
Using special primer Fixafond 400 by Fresco (primer contains silica) will hold the first coat very well and you would spend less time flattening the first coat.
Using the same kind trowel for Grained Marmorino as for Fine Venetian Plaster will leave a lot of scratches on the surface.
The fact is that you need Leppato stainless steel trowel (with beveled edges) not Lucido with just rounded edge. The Leppato will help you to apply first coat very evenly and compact the second without rolling the grain over.
Applying smaller amount of material than required will lead to uneven coat with a lot of scratches all over.
Apply material generously and keep it leveled to the size of the grains. Let your coat dry a bit before flattening it down.
Applying the second coat the same day will lead to cracks all over the surface.
Let the first coat dry overnight.
Flattening the second coat right after it was applied is a total waste of your time. It will simply create a mess on the wall.
Let the second coat dry a bit (depending on particular material and weather conditions, it can be 5 -10 minutes) and then go ahead with additional take off. But use a bit less material this time, squeeze the juice out of the Marmorino and spread it around. Let it dry a bit again and then begin to flatten it down gently compressing. The good indication of when to compress is when the coat starts getting matt because of losing the water into the first coat.
Compressing the topcoat without adding a bit of water will be shortening your working time and can result in an uneven finish with different appearance and shine.
Spraying a bit of water before you start flattening the material down will give you more working time and a nicer finish as well.
Overdoing the compressing or polishing will squeeze the water (with bonding materials) out of the fresh coat and can develop cracks all over.
Do the polishing very gently at the beginning gradually increasing the pressure. Be patient: let the material work for itself. Stop polishing when the surface becomes hard.
Applying the wrong sealer will ruin your work.
Applying water base Aquawax by Fresco will make Marmorino sing. Apply it with a rag or sponge and buff it when is dry. For the exterior projects use Parapierra sealer by Fresco and apply it with a sponge.
Exterior application of Marmorino under direct sunlight will ruin your finish.
Carefully plan your working day, use shadow areas to apply Marmorino.
Starting your project with Marmorino without an approved sample is not a good idea.
Always make the board sample and have your client approved it by sighing and dating the back of the sample.
VENETIAN PLASTER INSTALLATION @ CLUB MONACO, TORONTO →
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