Coating Reference Handbook - Hempel

HEMPEL
ABRASIVES, SPENDABLE R2b
Spendable abrasives are typically used only once or a few times
The are normally NON-METALLIC and typical examples are:
* Quartz sand
* Aluminium silicate
* Copper Slag
* Oven or Coal Slag
A lot of local products are found.
Spendable abrasives should be sharp edged and hard, they should be high quality,
washed with fresh water, dried and classified, and should not leave any foreign
matter on the blasted surface.
Suitable abrasives should comply with ISO 11126:1993.
For tank coating jobs, the abrasive should be checked according to the tank
coating specification before starting the job.
Sea sand and river sand are often rounded and chloride contaminated, and should
therefore be avoided for heavy duty coatings.
SIZE DISTRIBUTION:
The size distribution is often given in manufacturers own grade numbers and.
in mm.
Typical distributions are:
0.4-0.8 mm For general blasting, fine profile
0.4-1.2 mm For general blasting, somewhat coarse profile
0.2-2.0 mm For high profile blasting on old pitted steel
1.2-2.0 mm For high profile blasting on new, unpitted steel
Suitable abrasives grain size distribution should as a minimum comply
with ISO 11126:1993.
Mixture of grades for specific purposes can usually be supplied in the distributions
or mixtures thereof as requested.
ISO 11126 - Water Solubles Conductivity Measurements:
The ISO 11126 states as a requirement to conductivity of water extracts of
abrasives a maximum of 25 mS/m. This method is now described in page R6a,
and R6d.
INSPR2b ed3 VALIDITY SUBJECT TO CONFIRMATION 10/02/03 EMi