Rock Drilling T ools 38 www brunnerlay com Brunner Lay Tips on Drilling 1 Be Pr epar ed Experienced skilled drill oper a tor A v oid impr oper bit handling ie carbide a gainst carbide dama ge Drill rig pr oper l y lubrica ted Suffcient drilling accessories on hand K eep accessories c lean and fr ee fr om dama ge Striking f ace is squar e and tr ue 2 Star ting the drill Fir m f ooting f or the drill Align and collar the hole pr oper l y Be gin slo wl y and adjust the f eed and thr ottle as the bit buries 3 Drilling Maintain enough r ota tion f or good penetr a tion Ex cessiv e r ota tion will w ear the gauge Maintain cor r ect f eed pr essur e Insuffcient air pr essur e leads to a loose drill string and pr ema tur e w ear Suffcient air pr essur e is ideal to k eep the bit fr om bouncing on the bottom T oo muc h pr essur e will buc kle and bind the steel in the hole Ov er f eeding in har d r oc k will r educe penetr a tion Ov er f eeding in soft r oc k can lead to bur ying the bit and hanging the steel 4 Clean hole Blo w the hole fr equentl y w hen drilling deep Soft or mud dy g r ound can seep causing the steel to hang up Blo w with e v er y drill r od ad ded belo w the hole pr e v enting a plug ged steel 5 Drill dieseling Occur s with insuffcient f eed pr essur e Also ha ppens with full thr ottle w hen withdr awing the bit Dieseling hea ts up the drill and bur ns of f the lubricant R esults could inc lude a destr o y ed hammer Stop dieseling by r educing the drill thr ottle and incr easing f eed pr essur e 6 Changing bits T r y to f ollo w a lar ger bit with a smaller bit T r y to use new bits with new steel Use lubricant on bits as w ell as couplings and steel thr eads R emo v e bits with a bit wr enc h or r a ttle loose no bea ting with a hammer