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Finish:
The appearance of the paint film after drying under optimum conditions, -
given as high gloss (>90), gloss (60-90), semi-gloss (30-60), semi-flat
(15-30), or flat (<15). All figures are in gloss units and according to
ASTM D 523-67 (specular gloss, 60 degree geometry). The actual
appearance will depend on the conditions during application an
drying/ curing.
Flash point:
The lowest temperature at which a liquid liberates sufficient vapour to
form a mixture with the air near its surface which, if ignited,
will make a small flash, but not catch fire.
The flash points of Rangan Far, s paints are measured
according to the setaflash metho (closed cup).
The figures are given as guidance with view tolocal regulations for
precautions against fire during use. Substantial changes owing to
reformulation will be followed by the issue of a revised product data
sheet.
Adding thinner to paint may
change the flash point of the diluted material.
Volume solids:
The volume solids (VS)
figure expresses in percentage the
ratio:
dry film thickness
wet film thickness
The stated figure has been determined as
the ratio between dry and wet film thickness of the coating applied in the
indicated thickness under laboratory conditions, where no paint loss has
been encountered.
The method of determination follows the rules of ISO 3233/ASTM D 2697,
yet by drying at 25°c and 60% relative humidity for
7 days instead of drying at higher temperatures.
Volume solids are usually slightly higher than the theoretical value,
which is found by a calculation based on the paint composition
taking specific gravity and solid content of each individual raw material
into consideration.
Volume solids take into account that small amounts of solvents are usually
retained, and that air may be entrapped in the dry paint film either in
the form of vacuoles or as interstices in zinc silicates. Volume solids
are in better agreement with practical measurements of dry film thickness
than the theoretical value.
Dry film thickness (D.F.T):
Dry film thickness (D.F.T) is
indicated in a thickness frequently used in specifications. Note:
Several products are specified in different film thicknesses
for different purposes. checking of dry film thicknesses is, generally,
done with gauges calibrated on smooth reference steel panels.
Specific
gravity:
The weight in kilograms per
liter at 25°C/77°F an equivalent figure is given in Ibs per
us gallon.
For two-component products the
specific gravity is given for the
mixed product.
Theoretical coverage:
The theoretical coverage rate
of the paint in a given dry film thickness on a completely smooth
surface is calculated as follows:
volume solids % x 10
= m2/litter
dry film thickness
(micron)
In the product data
sheet the theoretical coverage rate is stated for an indicated by film
thickness (D.F.T) that is usually specified for the product. Some
products may be specified in different dry film thickness for different
purposes affecting the coverage rate accordingly. Theoretical coverage
rate can not be given for paint materials used for saturation of an
absorbing substrate i.e., wood, concrete, etc.
Drying time :
Drying time tested according to
ISO 1517. Records the time to elapse before dust will not stick on
to the painted surface.
Touch dry:
The drying time in the product
data sheet is “touch dry” unless otherwise indicated.
The drying time refer to a temperature of
25°C with adequate ventilation. “Touch dry”: a slight pressure with
a finger does not leave a mark or feel sticky.
Dry to handle :
The paint surface is sufficiently hardened to be handled with care without
coming off/being damaged.
Full cure:
The curing time is given for two- component products at 25°C . The
curing is accelerated at higher temperatures and retarded at lower
temperatures. For products where the curing time is
given at 25°C only, the following rough rule of thumb can be
utilized: Curing will stop almost completely below the temperature stated
under application conditions as the lowest temperature at which the paint
should be applied.
Pot life:
Roughly speaking, the pot life
for solvent –born paints depends on the paint temperature as
follows:
The pot life is halved at an increase in temperature of 10°C / 18°F,
and doubled at a decrease in temperature of 10°C / 18°F.
For Rangan Far products the pot life is usually shorter for
application by airless spray than for brush application. Thus the high dry
film thickness usually specified by
airless spray application is only obtainable within the pot life indicated
for airless application.
Note: pot life cannot be
extended by thinning.
Mixing ratio:
Two – component, chemically curing products are supplied as base(resin)
and curing agent( cure) in the correct mixing ratio. the
mixing ratio must be strictly adhered to, also when sub-dividing. Add the
curing agent to the base 30 minutes before use (at
25°C ), unless the pot life is (very) short,
and stir well.
Application method:
Gives the possible or
recommended method (s) of application. As a general rule, the first coat
of a rust-preventing primer should be applied by brush or airless spray to
obtain best possible wetting and penetration into the substrate.
Application by brush or roller usually
demands more coats applied to achieve the specified film thickness than
application by spray equipment.
Recoat interval:
The time required or allowed to
pass at 25°C or the relevant temperature range for the product
in question before the subsequent coat is applied. The
intervals are related to the temperature, film thickness, number of
coats, type of future (in service) exposure and will be affected
correspondingly. For maximum intervals the temperature in this context is
the highest surface temperature during the period. For some
products the interval is more critical in regard to undercoat
adhesion than others. If the maximum interval is exceeded it
may be necessary to roughen the surface to ensure adhesion of the next
coat. On the other hand, for some paint types the interval may
not be critical in respect of adhesion, but a primer coat
should not left unprotected for too long in an aggressive
environment. If nothing else is mentioned the indicated intervals
refer to recoating with the same paint. Other paints of
different types may require other (recoating) intervals.
After exposure of any painted surface in polluted environment thorough
cleaning by high pressure fresh water hosing or another appropriate
measure is always recommended before recoating.
Shelf life:
The time the product will keep in good condition when stored under cover
in original, sealed containers under normal storage conditions. Shelf life
is indicated only if it is one year or less at 25°C .it will
usually decrease at higher temperatures.
If no specific limitation is given,
paint should not be stored for more
than one year from the date of
invoice. This interval has been chosen
as a practical guideline.
Surface preparation:
The recommended degree of cleaning of the surface before painting. The degrees of
cleaning refer to ISO 8501-1:1988. Pictorial surface preparation standards for
painting of steel surfaces, unless otherwise indicated. For previously
painted surfaces the method and degree of preparatory cleaning is
generally indicated.
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