The following is Inpol Inc.’s suggested procedure for lubrication of a six-inch or 15.24cm hammer with Inpol-Lube. The procedure was derived from field tests conducted by Charlton Well Co., Charlton, Massachusetts, USA.
1. All hammers must be frequently disassembled and inspected for damage or wear. How often the hammer will be inspected depends on the drilling conditions and general condition of the hammer itself. Generally, most down-hole hammer manufacturers recommend, when used for standard dry drilling (little or no water), an inspection every 175 hours to 200 hours. Under hard drilling conditions, the hammer should be inspected and cleaned every 100 hours.
Notes: The hammer should be clean and in good working condition prior to adding Inpol-Lube. Check with your hammer manufacturer for inspection intervals and storage procedure. Inpol -Lube is an ester-based lubricant formulated with natural food grade vegetable oils that biodegrade over time. For that reason, it is not recommended for long-term, DTH hammer storage.
2. The hammer is first setup for per lubrication with 2 to 3 oz. or (59 to 89 ml). Then set in an appropriate holding jig and cycled for 20 sec. at 100psi. Making sure that the compound has dispersed thru the piston and reached the drill bit spline surface. The hammer is now reedy for drilling. Note: For a eight- inch hammer, increase by adding > 1 oz. (30ml) of Inpol Lube to all additions.
3. After 4 to 5 hours or 300 ft, 91.4m.of continuous drilling, add 2 to 3 oz. into the top of the drill string. At >300psi there will be ample air pressure to push the lubricating compound down the drill rod.