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View Full Version : 270 pound Mobile Core Drill Rig

12-09-2012, 03:08 PM
Good to have you here Peluk,

Was hoping you could show the guys a photo or 2 of your yellow core drilling machine you use at the beach? You sent me a photo of it a few years back but I didn't want to post it without your ok? Unfortunately, I don't know what happened to said photo.

-Tom V.

12-10-2012, 07:23 PM
Tom,the drill is a Mobile "Minuteman".It is made by Foremost or Mobile Drills in Indiana.It does cores or augered samples.They have a new motor on it now but it is basically the same.If I find the pics,I'll send them to you if you place your email address here.I'm no whizz at posting pics so you could post it if you would like to.

12-11-2012, 04:18 PM
See if this works, core drill used by Peluk in Nome, AK if I remember right?

-Tom V.


12-12-2012, 03:49 PM
Could you use one of these small drills to sample a placer claim for evaluation? How much gold would you need to find in a hole to decide it would be profitable for a one person operation? Sorry if this is a dumb question.

12-17-2012, 06:57 AM
The question is probably not being answered because many are unfamiliar with using a drill for sampling.I can't address this question right now but I may give you some typical drill info from a drill log I have here in front of me.I've checked out drill logs on other locations and there are often variations in sampling methods as well as equipment used to drill.

When I get a chance,I will post a thread on this log from "Hammond Consolidated Gold Fields" here in Nome.You'll probably be able to see that this drill will, or can,provide enough information to put you ahead of the game.

Steve Herschbach
12-17-2012, 12:42 PM
Actually lack of answers is proably due to it being a question asked as part of a classified ad for a totally different item. I have moved to the prospecting forum as a separate thread.

12-17-2012, 04:35 PM
Went to the site and here is my take.

I have a old Deep-Rock drill. Same-o, same-o. Only difference is mine is 2-cycle. I have fishtails, 3-winged, home-made reamers and even a couple core bits.

In the alluvial material along the river here, it is a complete failure.

I also have an Earthquake 2-man post-hole auger with an 8" auger bit. It could be easily mounted to the Deep-Rock tower, but it wouldn't matter. The auger hangs up in the cobbles/boulders and so the tower would tip over.

For around here, the auger needs beaucoup mass to hold it in place and some form of real down pressure.

Perhaps in your area, the alluvial material is much smaller or not as tight.

Geo Jim
12-18-2012, 05:02 PM
I will attempt to answer your question about how much gold you would need for a one man operation. Honestly this is impossible to answer with out a whole lot more information from you. Rather than that, answer this question, "Do you have cobbles or large pebbles to drill through?" If you answer "Yes", then the questioning is over. This machine will not be of any use to you because it will not drill through those rocks. If it did manage to drill through the gravel, then you could not trust the gold data. If you said, "All I have is sand." Then maybe more questions would get somewhere. The bottom line is you will most likely be very disappointed with this drill. This is made for taking soil samples, not gravel samples and never for gold samples.
Geo Jim

12-18-2012, 06:19 PM
Thank you Jim. I only have a dredging claim right now. I am trying to learn as much as possible so that in a few years, when I will be able to spend the whole season up north, I could possibly move up to a small shaker/bobcat operation. I would need to find or purchase a different claim. I know that you have to sample to evaluate a claim so that is why I was asking about these small drills.

12-18-2012, 07:59 PM
flyfishnv, I bought the 2-man posthole digger just for placer sampling. When that auger hangs up, it just about rips you arms off. And if one of you lets loose, someone can get hurt as it spins the handlebars around before the engine drops to idle.

The only two uses I've had for it after finding out my brilliant scheme was a failure was renting it out as a posthole digger and digging an outhouse hole.

bill-costa rica
12-19-2012, 05:01 AM

sounds like the only pleasure you would get from using that machine would be being able to be the first one to use the outhouse hole.


12-19-2012, 12:37 PM
Overtheedge, have you tried your core drill bits on frozen gravels? Have you thought about mounting it on an old vehicle/atv? How old is it and are you interested in selling it?

12-19-2012, 04:33 PM
No, I haven't tried on frozen though I suspect that the water used to keep the bit cool and lift cuttings would freeze. The way the thing works is you have a couple of settling pits filled with water and pump out of the far pit. The cuttings come up with the bentonite filled water (drill mud) and settle out in the first pit and the overflow goes into the second pit for recirculating.

One core bit is diamond, but the other is a home-made one using carbide brazed to pipe. I don't really want to sell as I still have to get my well drilled and the glacial clay locally has erratics embedded in it. The reason I haven't got it done yet is I bought the stuff used and between old fuel and storage, the carburetor needs rebuilt. And I get side-tracked during the summer: gone prospecting.

But it would be no problem for you to have a carbide core bit made locally. If you chose to drill frozen ground, you might need a boiler to reheat and keep the mud from freezing. Small engines pretty much require small bits and so not much mass/volume to the mud to stay warm.


12-19-2012, 06:14 PM
Sorry Ron,a lengthy response was lost when i went to post it.It stated I was not logged in.Of course I had to be to respond .That's enough for me.
The "Deeprock" Eric spoke of is a different type of drill.The Minuteman has an automotive transmission,downpressure capability,ability to be truck mounted on a frame below the bed...it's a different beast.You don't just need gold in your sample,you need to know how far above the gold bearing layer you could be also.A small drill cabn tell you a lot.The rotary drill is not for rocky ground but I use a 2 7/8" auger and it is suitable for my needs.I can reset when I get too much resistance.
On the beach,I don't even stake it.
Wow,I lost a lot of info and time on that one.

Steve Herschbach
12-20-2012, 06:14 AM
Having been around the forums since their inception many years ago I have found the Internet in general to be a poor place for word processing. The longer the item and the more time invested in it the better off i am doing it offline then posting when done. Sorry to hear we missed out on that one!

12-20-2012, 11:39 AM
Peluk brought out a good point. Mounting the drill/auger to a larger vehicle to counter the down pressure.