Page 15 - Piste Ciclabili

paint&thinner

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GIORNI

PREPARING

CONCRETE FLOOR

The concrete has to be clean, free from substances which decrease the adhesion, com-
pact and dry. Always verify, before applying:

MOISTURE IN CONCRETE EFFLORESCENCE AND LAITANCE
The following test “plastic Sheet Method” is an easy, On new or old concrete check for components
fairly reliable method to detect the presence of outcrops which appear as white non-adherent dust.
moisture (ASTM D4263-83). Tape a plastic sheet on They must be removed by mechanical abrasion and
the concrete surface being tested. After 24 hours removing the causes of any swelling or detachment
remove the plastic sheet and measuring with hy- of paint:
grometer. Cementitious substrates must not have a - new concrete, not yet completely dried
residual moisture content over 4%, - occasional infiltration or constant moisture
- rising moisture
PORORSITY OF THE SURFACE
The absorption of the cement can be verified by pou- CURE OF NEW CONCRETE
ring water on the surface. If it soaks rapidly, paint A curing period of at least 40 days before painting
will likely adhere to the surface after the necessary is required for the concrete to react and become
pre work is performed. If the water remains on the less alkaline. In presence of basicity, proceed with
surface or is absorbed very slowly It’s necessary to washing with hydrochloric acid solution followed by
etch any bare or previously uncoated concrete to rinsing and drying. Apply just on neutral concrete
impart some roughness and porosity by using a so- (ph7). if the concrete is old, it’s necessary to remove
lution one part muriatic acid in nine parts of water. flaking parts.
Rinse well with water. After floor is completely dry,
to proceed with application. If this treatment is not
sufficient, to proceed with mechanical abrasion.

In the presence of old coated floor verify compatibility with the new cycle and obviously
the adhesion of the old paint. Make an adhesion test by cross-hatch and strop with tape.
Proceed with the solvent method application, rub the paint with a white cloth soaked in
thinner to see how easily the paint will dissolve.
If the top layer is not well anchored to the support, or the support is covered with an epoxy
or polyurethane, proceed with mechanical abrasion.
Read carefully the data sheet before applying paint.