[Coral-List] Drill Inquiry

Thu May 17 09:19:35 EDT 2018

I have seen Mark's solution used to drill short cores in coral for growth
measurements. In those instances, it took about a tank of air per 10-15 cm
core as I remember. Even if my estimates are of by a hundred percent, that
would get you 20-30 cm into the reef. Also, keep in mind that most of those
coring operations were in shallow water. Because the proposed system is
pneumatic, the same depth relations we think about when breathing from a
tank apply here - go to ca 30 ft and you'll need twice the air volume - to
99 ft double again. And, on top of this, friction in the hole increases
exponentially with depth (more surface area --> more needed torque). If you
have a reasonable surface-supplied air system capable of putting out the
volume adjusted for working depth, this could be viable - and the pneumatic
option might provide more instantaneous torque than simple and constant
rotation - but, if you start to get stuck, it can get you REALLY stuck. I
don't see SCUBA tanks as a viable option.

Dennis

On Wed, May 16, 2018 at 1:25 PM, Mark Tupper <Mark.Tupper at utt.edu.tt> wrote:

> Hi David,
>
> For your application, I would recommend using an underwater pneumatic
> drill over a battery-powered model. You will typically get twice the power
> output for the same sized drill. Electric drills lose about half their
> power output from the armature to the drill bit, so a 1750 Watt electric
> drill actually produces about 875 Watts at the bit. In pneumatic drills,
> power in equals power out, so a 1750 Watt drill puts all its power to the
> bit.
>
> You can buy specialty underwater pneumatic drills (both rotary and hammer
> versions) here: https://www.egamaster.com/en/component/egamaster/
> categorias/508/Tools_for_underwater_use/PNEUMATIC
>
> They are a bit expensive, so one way to go cheap is to use a garden
> variety pneumatic drill (easily found in hardware or auto parts stores).
> The drill can be hooked up to a portable compressor on a boat, or simply
> powered by a SCUBA tank - you will just need to remove the second stage of
> your regulator and find a fitting that can connect the drill to your air
> hose. You may need a dozen tanks for a couple of hours' work but a few
> dozen air fills is a whole lot cheaper than one compressor. To stop the
> drill from rusting, remove the casing and soak the drill overnight in
> diesel, then let it dry. I used this system for several months with no
> problems.
>
> Cheers,
> Mark
>
>
> Prof. Mark Tupper | The University of Trinidad and Tobago
> Programme Head | Maritime and Ocean Studies
> Chaguaramas Campus | Tel: (868) 642-8888 Ext#22126 | Mobile: (868)
> 385-2545
> mark.tupper at utt.edu.tt | www.utt.edu.tt
>
>
>
>
>
>
>
>
> -----Original Message-----
> From: coral-list-bounces at coral.aoml.noaa.gov [mailto:coral-list-bounces@
> coral.aoml.noaa.gov] On Behalf Of David Weinstein
> Sent: Wednesday, 16 May 2018 7:13 AM
> To: Dennis Hubbard <dennis.hubbard at oberlin.edu>
> Cc: Margaret Miller <m.miller at secore.org>; Coral Listserver <
> coral-list at coral.aoml.noaa.gov>
> Subject: Re: [Coral-List] Drill Inquiry
>
> Hello Margaret and others,  I was wondering if anyone had any more
> information about thesebattery operated underwater rotary or hammer-drill
> systems Margaret asked about.  Specifically, we are wondering if they are
> strong enough to actually take short cores (about a m) through coral
> limestone substrate such that the cores have a diameter of around 5 cm?  We
> would like to do some simple drilling but want to make sure these electric
> systems are strong enough to fit a coring tube onto them and retrieve a
> core (specifically at 45 m).  Thank you.
> David Weinstein
> ---Zuckerman Postdoctoral  Scholar
> Hebrew UniversityInteruniversity Institute for Marine Sciences in Eilat
> http://www.rsmas.miami.edu/users/dweinstein/
>
>
>
>
>
>
>
> On Sun, Apr 29, 2018 12:39 AM, Dennis Hubbard dennis.hubbard at oberlin.edu
> wrote:
> Hi Margaret:
>
>
>
>
> I wasn't familiar with this unit so I did a little surfing. It appear that
>
> it is pretty much a cordless drill but with some sort of waterproofing. I
>
> do have a fair bit of experience with what look like similar units in a
>
> wood-working setting and have spent a lot of time tinkering with everything
>
> from small throw-away pneumatic systems to larger.... and much larger....
>
> coring systems. Unless there is something extraordinary in the battery life
>
> and torque, my sense is that you're going to be frustrated on both fronts
>
> unless your goal is to insert small pins as markers.
>
>
>
>
> I know that Rich Berry lurks on the site and when I have any questions on
>
> suck things, he's been my most dependable resource. If he reads this, I
>
> hope he will contact you. If not, let me know and I'll ask his opinion
>
> offline and try to get the two of you together. He's spent more time around
>
> rugged and crazy marine hardware than anyone I know.
>
>
>
>
> Best,
>
>
>
>
> Dennis
>
>
>
>
> On Mon, Apr 23, 2018 at 1:06 PM, Margaret Miller <m.miller at secore.org>
>
> wrote:
>
>
>
>
> > Dear Coral-Listers,
>
> > We are contemplating a significant investment in one of the new
> > battery
>
> > operated underwater rotary (Nemo V2 Divers Edition) or hammer-drill
> > (Nemo
>
> > Divers Hammer Drill). I would appreciate to hear from folks who may
> > have
>
> > experience with either of these. How many holes on one battery charge
> > (3
>
> > vs. 6 amp)? What types of reef substrate have been successfully (or
> > not)
>
> > drilled. Please email me off-list with any advice.
>
> >
>
> > Many Thanks,
>
> > --
>
> > *Margaret W. Miller, PhD*
>
> > *Research Director*
>
> > *SECORE International*
>
> > *www.secore.org <http://www.secore.org>*
>
> > *614.973.3559*
>
> > m.miller at secore.org
>
> > _______________________________________________
>
> > Coral-List mailing list
>
> > Coral-List at coral.aoml.noaa.gov
>
> > http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
>
> >
>
>
>
>
>
>
>
>
>
>
> --
>
> Dennis Hubbard
>
> Chair, Dept of Geology-Oberlin College Oberlin OH 44074
>
> (440) 775-8346
>
>
>
>
> * "When you get on the wrong train.... every stop is the wrong stop"*
>
>   Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"
>
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-- 
Dennis Hubbard
Chair, Dept of Geology-Oberlin College Oberlin OH 44074
(440) 775-8346

* "When you get on the wrong train.... every stop is the wrong stop"*
 Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"