Author Topic: Underwater drilling  (Read 2747 times)

Offline irnbru

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Underwater drilling
« on: March 31, 2013, 10:27:17 pm »
Hi - I may need to attach a bolt to some brickwork which is underwater (4m).

Is there a power drill for this type of thing or am I looking at a few hours of underwater misery with a hand drill

Online Les W

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Re: Underwater drilling
« Reply #1 on: March 31, 2013, 11:58:12 pm »
Fresh water or salt water?

In fresh water a battery drill may well do the job as the water isn't very conductive, but you will need to dry it out thoroughly after if it is to survive. A battery drill in salt water, being very conductive, will probably not be any use...

It is possible to use air tools under water as well so if you have access to an air drill and a supply (Dive cylinder or compressor) then that might be the way forward.
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Offline bograt

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Re: Underwater drilling
« Reply #2 on: April 01, 2013, 12:07:37 am »
Air is preferable but you might have problems with freezing valves if you use a bottle.
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Offline irnbru

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Re: Underwater drilling
« Reply #3 on: April 01, 2013, 10:26:41 am »
Hi - many thanks. It is (almost) freshwater pH 6.0

                          PROJECT          TAP WATER
Al  Aluminium     1.43               0.02
B  Boron            <0.2              <0.2
Ca  Calcium       1.156            15.06
Fe  Iron             0.033            0.0848
K  Potassium     0.99              0.98
Mg  Magnesium  0.85             1.95
Mn  Manganese  0.14             0.01
Na  Sodium         5.75             7.37
P  Phosphorous  0.02             0.73
Si  Silicon            2.91             1.96
Sr  Strontium      0.014           0.041
« Last Edit: April 01, 2013, 10:37:09 am by irnbru »

Online Les W

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Re: Underwater drilling
« Reply #4 on: April 01, 2013, 10:22:08 pm »
Battery drills should work underwater so long as the water isn't conductive enough to short the current away from the armature. I'm pretty sure that they have been used before in fresh water. Salt water is probably too conductive, the current will short through it and not drive the armature.

Drying it out thoroughly is important as leaving it wet from submersion for any length of time will result in corrosion and the leaching out of lubricants. It might be a good idea to disassemble it, dry the parts and re lubricate it before putting it away for any length of time after.

What I wouldn't suggest is that you try working under water with a mains drill, that would be a bad idea...  :-\
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Offline keri.lewis

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Re: Underwater drilling
« Reply #5 on: April 02, 2013, 11:01:52 am »

If you decide to use an impact tool like an air chisel you need to be careful of the shockwaves from the impact. Water carries shockwaves a lot faster and more efficiently than air (as a diver you know the effect on how you hear things..). So the net result is the same as louder noise. It is entirely possible that an air chisel is "loud" enough to burst an eardrum without suitable protection.

At the moment I am planning to experiment with the airgap created by a pro-ear mask and earplugs underneath for protection... if I can't hear anything afterwards it'll have failed!

Mask is like this -

http://www.amazon.co.uk/Scuba-Diving-Mask-Around-Protection/dp/B0021OZ1PW

It provides an air-gap to reduce transmission of the impact.. hoping this will be enough as when we tried the air chisel out of the water it was pretty loud!

K

Offline Gareth Davies

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Re: Underwater drilling
« Reply #6 on: April 06, 2013, 11:37:05 pm »
If the job only requires a small single bolt in a limestone block then a spit is easily installed in about 10 - 15 mins. I've put a number of bolts in underwater to winch rocks clear and its quite an effective method. Its certsunly cheaper than trashing an expensive drill.

Offline Pitlamp

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Re: Underwater drilling
« Reply #7 on: April 08, 2013, 09:54:26 am »
The issue of hearing damage with power tools underwater has been well documented in CDG literature over the years (starting in Oliver Lloyd's era). Long before the vibrations become intense enough to affect the eardrum itself there is a great risk of damaging the auditory nerve endings in the cochlea (hearing organ) of the inner ear. This damage would be permanent. My advice is not to mess with power tools underwater unles you've thoroughly reasearched the hazards and mitigated against them in such a way as to eliminate risk. You only get one set of organs of hearing and when they're gone they're gone. And tinitus is such a drag . . .

I think the problem with electric drills is the issue of incompressibility of water in the percussion mechanism which can adversely affect efficiency. If you really must try this, try it with someone else's drill!

Frankly, banging in an 8 mm anchor with a small hammer is by far the easiest option for your situation, as Gareth has pointed out.

(Readers might like to note that I've now been in discussion with irnbru directly about this; I'm really posting these thoughts here to emphasise the problems of certain options discussed above, in case searches by others in future pull this topic up.)

Online SamT

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Re: Underwater drilling
« Reply #8 on: September 24, 2017, 11:01:19 pm »
Little known fact: The new & powerful Nemo SDS Rotary hammer can chisel & drill rock at 100M depth, and allows BATTERY REPLACEMENT UNDER WATER! This brush-less beast out performs hydraulic & pneumatic tools in both power and endurance. Limited first production batch now available for pre-orders at: http://nemopowertools.com/product/nemo-sds-rotary-hammer/

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Online SamT

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Re: Underwater drilling
« Reply #9 on: September 24, 2017, 11:02:29 pm »
Little known fact: The new & powerful Nemo SDS Rotary hammer can chisel & drill rock at 100M depth, and allows BATTERY REPLACEMENT UNDER WATER! This brush-less beast out performs hydraulic & pneumatic tools in both power and endurance. Limited first production batch now available for pre-orders at: http://nemopowertools.com/product/nemo-sds-rotary-hammer/

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the above popped up on my Facebook feed.. just thought I'd share it hear (sic)

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Offline Pitlamp

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Re: Underwater drilling
« Reply #10 on: September 25, 2017, 07:12:46 am »
Thanks for that Sam - it's certainly of interest.

Online SamT

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Re: Underwater drilling
« Reply #11 on: September 25, 2017, 01:24:21 pm »
I've just seen the price!!!  :o

Still, hearing issues notwithstanding, I just thought I'd mention it.  Could be something a few people club together for,  such as the CGD, for communal use etc.

Offline pwhole

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Re: Underwater drilling
« Reply #12 on: September 25, 2017, 06:11:30 pm »
I guess for what it does, it's pretty good value, especially if they've damped the noise. I particularly like the 'sterile' model for lab use.

Offline adrian paniwnyk

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Re: Underwater drilling
« Reply #13 on: September 25, 2017, 08:52:59 pm »
Has anybody used a rechargeable drill underwater or is it something that has only been talked about in practice but not actually done? It's just that we have an old Bosch GBH 24vdrill and we were talking about doing just this. We will tell you what happens!

Online SamT

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Re: Underwater drilling
« Reply #14 on: September 26, 2017, 12:47:48 pm »
We had a brand spanking new Makita Lion 18v that got properly submerged in a leaky 'dry' bag during a hours worth of wading on its first ever trip.

The drill was OK (and still is a good few years later) after I'd dropped the gear box apart to empty the water!! Plus I left it in an airing cupboard wrapped in silica gel sachets.
 
Two of the batteries survived after the same treatment as above.  This was principally because the circuit boards withing the batteries seemed to be coated with a water proof sealant layer.

The third battery however was completely fried with the chips etc on the circuit board actually burnt. 

I guess it depends on the complexity of the electronics within your drill.  I wouldn't expect switch gear etc to last very long at all as they'll soon rust/corrode.  Cells withing the batteries would be similar I suppose.  I recall some old bosch NiCad cells being wrapped in paper.  :confused:




Offline adrian paniwnyk

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Re: Underwater drilling
« Reply #15 on: September 26, 2017, 08:06:19 pm »
Must admit hadn't thought very much about what might happen to the power supply.
One option we have is a pair of exceptionally heavy lead acid batteries in a ammo tin which I assume might be reasonably waterproof.

Offline MJenkinson

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Re: Underwater drilling
« Reply #16 on: September 26, 2017, 08:28:53 pm »
I know Mr Cordingley installed a ring bolt in Malham using a star drill (ye olde SDS).