When installing threaded rod with epoxy for structural fastening. Why does hilti require compressed air, and not just a vacuum with a straw like nozzle on the end? The brush makes sense, but i tested it just to see if there was a difference, and the hose works just as well, actually a bit better.
Hilti injectable adhesive anchors require compressed air that is delivered at a minimum of 90 psi and 3.5 cfm as indicated in the Instruction for Use. Furthermore, the published load values in our technical documents are based on the 2x2x2 (blow-brush-blow, 2 times) cleaning procedure. The Hilti Safe Set which incorporates our hollow drill bit and vacuum system may be an alternative to the 2x2x2 procedure and will be included in the applicable product technical documents and Instruction for Use. For more information regarding the effects of improper hole cleaning on the capacity of the anchor, please refer to this video.