Selected Answers

From Pedro Juan Moreno Junco of IPT PERU SAC on September 29, 2020:
In order to determine that the abrasive to be used ...read more In order to determine that the abrasive to be used in the field is clean, two stages or moments must be considered. 1) Before starting a blasting process 2) During the abrasive blasting process, when collecting the abrasive (steel shot, garnet, copper slag, etc.) 1) For the first case, the vial test described in the ASTM D7393 standard can be used to qualitatively verify that the abrasive does not contain fats, oils or any other contaminants. It is also necessary to check the conductivity of the abrasive to verify the amount of total salts present in it. To do this, the ASTM D4940 standard must be used, which indicates that the measured value should not exceed 1000 uS / cm, I recommend that it not exceed 500 uS / cm. In addition to these rapid tests carried out in the field, it is necessary to verify the quality certificate of the abrasive that at least meets the requirements described in the standards SSPC-AB1, AB2, AB3, AB4, ISO 11126, ISO 11127 mainly With these initial tests you can have a more precise criterion that the abrasive is suitable to start an abrasive blasting process. 2) During abrasive blasting, when recycling the used abrasive (for example steel shot or garnet) I recommend the following points: - Use machines that clean shot, they are used both in workshop work and on site, which improves the quality of work. - Have an Inspection Points Plan for recycled abrasives, in which samples are taken again from time to time and re-evaluated under the ASTM D7393 and ASTM D4940 standards.

From Wole Abimbola of Navante Oil and Gas Company Limited on September 28, 2020:
The most common way to be sure of an abrasive's cl ...read more The most common way to be sure of an abrasive's cleanliness is by Viral Test. Reference document; ASTM D7393 Standard Practice for Indicating Oil in Abrasives.

From Jaime Marcos of Profesional independiente on September 28, 2020:
To achieve good surface preparation by blasting, c ...read more To achieve good surface preparation by blasting, clean, dry compressed air is required. But the selection of the abrasive is also important, which must be clean, classified and dry. Once the abrasive to be used has been selected, it is necessary to check, on site, at least: granulometry, cleanliness (absence of contaminants), humidity, presence of salts. The applicable ISO Standards are: • ISO 11124 Specifications for metallic abrasives. • ISO 11125 Test methods for metallic abrasive materials (Sampling. Granulometric analysis. Hardness. Apparent density. Percentage of defective particles. Foreign matter. Moisture). • ISO 11126 Specifications for NON-metallic abrasives. • ISO 11127 Test methods for non-metallic abrasive materials (Sampling. Granulometric analysis. Bulk density. Hardness. Moisture. Determination of water-soluble contaminants. Determination of water-soluble chlorides).