In the meantime, with needing to clear a small level accessed via couple of risers of large rocks from previous blasting without using enough blasting medium (as explained by ex-miner member), ordered
- "feathers"/splitting wedges - 14mm=9/16ths" yes, but also 10mm=3/8ths"
- smaller SDS battery / cordless SDS drill
The unusually small 10mm "feathers" - hopefully SDS drill can do 10mm holes in the hard granite with cordless drill - whereas 14mm my instinct says (and various online commentators say) that is a bit of an "ask". Need is to break up blasted-out but not shattered boulders only inches dimension apart from length up to 3ft - so can easily move to the raise and lower down in cargo-net (tramming level below - cannot simply throw down).
"Smaller" cordless SDS drill - needs to easily go into a bag which can be carried down the ladders into the mine. Easy to put out-of-the-way until needed. And cost - be something you could cope with loosing as it's a bit of an envirnment down there.
Dust - instinct is to do bigger version of bottle used when mag-base drill for steel in workshop. Use scriber pushed through cap of plastic bottle like milk bottle, and spray enough water onto drill to make drilled material into a slurry (as you also do with watering can when using a gasoline "Stihl saw" to cut rock).
No idea how this will pan-out in reality. Sometimes you have to lunge at something. Whilst none of this is necessary, it leaves some of us lugging largish boulders along the overhead level and lowering to tramming level.
Thanks everyone for hints.
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I found that my Makita rock drill cut satisfactorily fast in NH granite with a 1/2" bit and bought the splitting sets to match. An adjustable nozzle spray bottle of water was enough to control the dust without wasting the limited water supply, with a bit of soap added to make it wet the fine powder better.