Hi John, I'm going to ask a different question here. Maybe there's someone else too that has useful experience. I know the sierra blaster and micro blasters have been talked about a lot here on T-net already but I haven't been able to find great answers to my question yet.
I am interested in a micro-blaster or sierra blaster for mineral collecting and possibly gold prospecting purposes. It's one of those things I don't exactly have a spot for right now where I NEED one, but I tell myself I will use if I had one and seeing a good deal on a used sierra blaster I'm wondering if I should jump on it. I'm looking for the lightest, most portable system. First, I thought the original microblaster with one head and a pull lanyard trigger would be best because no compressed air or electricity source is needed for a trigger. Then I realized that with only one head you don't have any control over how rock will break. I also read that the microblaster charges can be pretty finicky while sierra blasters are more robust. How compact of a system can ou expect running a sierra blaster of a battery? How big of a battery is needed and can all sierra blaster systems be used with a battery? Also, is one of these really practical for trying to get crystals out of wall rock or would they be too destructive? I read the sierra blaster charges pack more of a punch.
Then there's the drill and weight associated with that. Not sure how many holes you can drill on a charge.
Just looking for some advice, thanks!
If I were buying a system new, I would go with the Sierra Blaster. The charges are a bit larger (10mm diameter vs 3/8) and waterproof. Both can be used with multiple heads and weigh similarly. They hold 1-2 grams of material, and you can add booster cartridges with either if you are able to drill a deep hole.
Both companies have a similar pricing model - their equipment is expensive, but the charges are reasonably-priced. Considering that a blasting cap is $7+ and a small pyrotechnic rock breaker from Autostem or Royex is around $10, paying $1-2/ea for the Sierra Blaster or EZ-Break charges isn't too bad.
The compressed air for the "shock tube" initiation on the EZ-Break isn't a big deal if you can rig up a regulator to use bulk CO2 paintball tanks. You can also use a CO2 bike tire inflater.
On the Sierra Blaster, you have an electric match that needs around 1amp to fire. This is the same system that pro fireworks enthusiasts use to shoot their cakes and mortars, and those are often fired from a LiPo drone battery that weighs around 1/2lb. You can also use a "blast box" like you use for real blasting. Unfortunately, they may not sell you one without a blaster's license.
Either of these will break several cubic feet of rock with one head if you are shooting a boulder or something with 2 exposed rock faces. Expect to do more drilling and more shooting if you are trying to dig something out of a solid wall of rock in a mine/etc. It still works, but it's less dramatic.
Get a high quality cordless drill in any case. The Ryobi 18V isn't beefy enough. Go with at least the DeWalt or Milwaukee in a model that is rated to drill 1" holes and takes SDS+ bits. The 36V models are even better, but more expensive, and of course the batteries cost more. Get a set of drill bits in the right diameter, from 4 inches long, to 6, 8, 12, 16 and 24". Do not try to drill the holes in one pass - start with a short drill and keep changing bits as you go. Those little drill bits get hot FAST and you really want to rotate through them so that they don't burn up. They also wander a lot if if you drill with one big drill.
If you are shooting in-place rock, I recommend making a "burn cut" or drilling a cloverleaf pattern of bigger holes in the middle of the rock you are trying to break. Start small and then ream them out to 3/4" or even 1" if possible. The rock needs somewhere to expand into when you are breaking into a hard mass of stone.
Get extra batteries, so that you can swap them out as well as let them cool down between holes. Batteries overheat just like drill and bits do.
Also, start a "blast log" and document your work. You my want to apply for a blaster's license in your state later, and you can use this as "experience" in places like California that require "3 years of documented blasting experience" in order to apply.