TEMPERATURE
Waterborne paints are mainly composed by water dispersed resins which need a minimum Temperature, generally not lower than 10°C to complete drying.
If environment Temperature, both of the surface to be covered and of environment, are lower than 10°C the features of the dry film might be altered. During colder and humid season we advise to air the premises increasing Temp over 15°C and reducing moisture below 60%
COMPATIBILITY WITH TIMBERS
Check the type of timber which has to be painted, if broad leaf or conifer. Treatment of broad leaf big grain timbers like oak - iroko - niangon - meranti mahogany can cause several problems during impregnation phase carried on with waterborne products, due to tannin which are extracted during dripping. Specific products for these timbers must be used.
Sanding before impregnation must be done by 150 grain sanding paper and afterwards two coats of topcoat must be applied. The first one must be reduced, then sanded and finally recoated by the second one without reducing, at 150 m. Waterborne paints allow to migrate towards film surface all substances previously contained inside lignin without being damaged and when dried crystal is removed you can obtain a film perfect and without any defect. We advise to control regularly the condition of sanding stripes, to set calibration carpet speed between 6 and 8 Mt/min and roller speed at 14/16 Mt/min to reach a ration between them at 1 : 2.
The sanding paper for which we found best results is : 80 grain for the first roller, 120 for the second and 150 (or 180) for the third one. Second and third sanding papers should be not spaced and treated with antistatic material. The last one is in accordance to the conifer chosen
timber .180 grain can be used for fir, Canadian cedar, hemlock, 150 grain for fir, larch, yellow pine and douglas. Conifer timbers contain high concentration of resin which are discharged in late Spring; this feature gives waterborne finishes an advantage in comparison with solvent based which are vulnerable to resins leaking out. These resins irreparably damage film surface . Drying of these resins gives making of a crystal whose mechanical removal create a surface hole sensitive to be attacked by funga, mould and weather agents.
Enamelling of wood by waterborne paints faces the same problems than solvent based one, but resins and inhibiting substances leaking out deeply jeopardize the aesthetic aspect of covered substrate.
Broad leaf treatment is very difficult because tannin contained inside the grain are absorbed by lacquer and driven to the surface; stripes and small black cones may appear and these totally spoil the aspect of surface itself.
Varnishing of conifers like pine, yellow pine, larch and Douglas is not advisable for high resin concentration which, freely leaking out on the surface, creates wide yellow stains and, on expulsion spots, small black holes.
We therefore suggest to use timbers like white fir and hemlock to obtain a long lasting and easy to maintain lacquering and to apply at least two coats of ECO VERNIFOND WHITE WB BASECOAT before finishing by enamel.
COMPATIBILITY WITH STAINS
When covering indoor surfaces it is needed to control which kind of stain has been used to stain timber. The first coat may solubilize stain pigments and when sanding they are removed highlighting an uneven staining.
COMPATIBILITY WITH GLUES
When paining indoor surfaces you must always check glue type which has been used to stick veneers to substrates. Glues having seal lower than B 3 (DIN 68602) or D 3 (EN 204) may create crackles problems and bubbles on film, moreover lifting of glued layer.
COMPATIBILITY WITH SEALERS
Waterborne paints normally have basic Ph (higher than 7), therefore they may have compatibility problems with acetic silicon sealers (Ph lower than 5) which are used to seal frame glass. We advise to use neutral silicon sealers.
Both outdoor and indoor frames nowadays have gaskets having various sizes, colours and resistance. The maximum care in choosing them must be paid because they must be compatible with waterborne paints when these are used.
Small co-solvent percentage contained inside waterborne paints may melt gaskets when they are not compatible and they will be merged with paint and painted substrate. When you try to open the frame the film is then broken or even substrate might be deeply damaged. We advise neoprene gaskets or to ask for compatibility and resistance data both to paint and gasket suppliers.
VARNISHING EQUIPMENTS
Waterborne paints make common varnishing tools rusty; we therefore advise to use varnishing pumps endowed with stainless steel stalks.
We advise against using same equipments for waterborne and solvent based paints but if, for economic reasons, it is not possible to have two pumps we advise the following cleaning cycles:
· From solvent based paint to waterborne paint:
· Wash by using same thinner as paint (N/C, PU or white spirit)
· Wash by pure and perfectly clean acetone
· Wash by water
· From waterborne to solvent based paint:
· Wash by water
· Wash by pure and perfectly clean acetone
· Wash by using same thinner as paint (N/C, PU or white spirit)
Application pressare and spray guns nozzles are advise on each technical data sheet but we advise to check now and then tools tatus, from suction tube to high pressure tubes, from spray gun to piston gaskets, from sieve filters and gun butt to the condensate drain. We list standard working conditions when using waterborne paints:
· Traditional spray gun: pressure 3 - 4 Atm. Nozzle 1.9 - 2.5
· Airless pump: pressure 120 - 140 atm; Nozzle 09 - 011; Gun butt filter 100 m.; sieve filter 100 mesh
. Airmix pump: pressure 100-120 atm; nozzle 09 - 011; gun butt filter 150 m.; sieve filter 100 mesh.
Advised spray booths are both dry and water ; the former is preferred for easy maintenance, the latter for better overspray cutting down. To summarise we advise dry spray booth for waterborne paint usage less than 50 - 100 Kg per day and a water spray booth endowed with sludge separator for higher consumption. Paint remains and sludge are considered by general legislation as industrial wastes and it is totally forbidden to drain them inside sewer system.
They must be disposed in accordance to each Country Law.
STORAGE
Waterborne paints contain an extremely low solvent percentage and have flash point higher than 55°C. Therefore no special electric equipment are required in storage departments and generally IP 54 is accepted by safety Authorities.
Download Quick Guide to use of Vernites Waterbased Finishes
Click here for procedure sheet for external finishes
Click here for procedure sheet for internall finishes
Exterior Finishes: click here for details
Interior Finishes: click here for details
For Technical and Health and Safety Data Sheets on the full Vernites Range - Click here
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Falcioni Airless Pump for Waterbased Paints
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