Coating Reference Handbook - Hempel

HEMPEL
TRUE SURFACE AREA R15a
PROJECTED TRUE
SMOOTH" "TOPOGRAPHIC"
SURFACE AREA SURFACE AREA
SURFACE AREA RATIO (Estimated).
Rz "SMOOTH" "TOPOGRAPHIC"
micron
30 1 1,27
40 1 1,36
50 1 1,45
60 1 1,54
70 1 1,63
You may think that this affects the paint consumption of the
primer coat, but this is not the case with Standard HEMPEL
specifications - i.e. if the surface roughness is specified
in the specification, and if the guidance for DFT-measurements
given in this booklet and in HEMPEL'S Code of Practice 0209-1
is followed
Only in three cases will compensation have to be considered:
A: When applying SHOPPRIMERS.
Reference is made to the TECHNICAL DATASHEETs and
section R7 in this booklet.
When applying SHOPPRIMERS, their dry film thickness
is often lower than the roughness of the substrate and
they dry so quickly, that the film follows the contour of
the roughness.
B: When surface roughness deviates from that specified.
In this case refer to page R15b.
C: If PrEnISO 19840 is referred to in the specification
including its normative reference section.
Then compensation will have to be done depending
on substrate roughness.
Study the standard carefully if You meet it, also when
responding to the specification.
INSPR15a ed3 VALIDITY SUBJECT TO CONFIRMATION 28/11/06 EMi