Problem Solving Forum
November 22 - November 28, 2010
What quality control checks can I use to assure the cleanliness of steel abrasive in a fabricator's or shipyard's shop?
Selected Answers
From
Craig Wallbank of W Abrasives on
November 24, 2010:
Just further to my earlier post: yes, a scree ...read more
Just further to my earlier post: yes, a screen analysis is always a good procedure to do, to see if the mix contains dust or contamination. Dependent upon the size, it will usually be found from the 50 mesh down to and including the pan. If this is the case, then possibly more airflow is required at the separator to remove this unwanted and potentially damaging waste.
From
Craig Wallbank of W Abrasives on
November 24, 2010:
The cleanliness of the abrasive is dependent ...read more
The cleanliness of the abrasive is dependent upon if the process is equipped with an air wash separation system. Using metallic (steel) abrasive is by far the most cost-effective way and can give higher production rates over mineral abrasives. There is a section in the SSPC-AB 2 spec that tells how to test recycled abrasive. The recycled abrasive appears to be suppliers of this material and not the abrasive within the shotblast machine itself. As described above the airwash separation system is paramount to the operation and needs to set correctly to remove ALL contamination from the blasting process, but to leave the 'clean' useful abrasive within the system. Please also note that recycled abrasive may have previously been blasted on projects that may have contained lead paint, i.e., old bridge structures, etc., so it is imperative that the abrasive is clean by the supplier of this material. NEW is always the best, as you know where it has come from. Hope this helps.
From
remko tas of Futuro SRL on
November 24, 2010:
Size and mix can be checked with diferent mes ...read more
Size and mix can be checked with diferent mesh size strainers (about 2-3)
Sharpness or roundness can be checked visually by comparing with new steel abrasive. Check for contamination with oil and grease by putting some grit in a glass of warm water and look for oil floating. Salt contamination can be checked by putting some grit in a glass of water and running a conductivity test.