Can anyone lend us an underwater drill?

[Pitlamp]

We have had one of these on order for almost 4 months:

Nemo SDS Rotary Hammer - 50M - Nemo Power Tools

See pricing and learn more about Nemo SDS Rotary Hammer - 50M %

nemopowertools.com

But none has been delivered to this country for a while so we're on a waiting list. However, we have an obstacle in a very shallow sump (in the Dales) in which we need to drill a number of 14 mm holes, to use plugs and feathers. The sump is very close to daylight and easy access.

This is a long shot but does anyone have a submersible cordless electric drill such as the above which they'd be prepared to lend to us for this one off job? Or any other suitable drill? (But it needs to be reasonably compact as we're working in a restricted space.) Please could you PM me if you're able to help?

Thanks.

 

[georgenorth]

Would a hydraulic core drill be an option? Obviously you’d need to be able to get a hydraulic power pack to the entrance! Might be easier to get hold of than an underwater cordless drill though…

 

[Pitlamp]

Thanks George - but probably not practical in this particular location.

I'm almost toying with the idea of buying one of these dirt cheap things and using it as a sacrifical item: https://www.aldi.co.uk/ferrex-20v-rotary-hammer-drill/p/809036556437801

Do folk reckon this would work effectively? (Maybe bodged to receive its supply via a cable from a battery on the surface?)

What about using it with an attached battery - would that be safe?

 

[bograt]

Thanks George - but probably not practical in this particular location.

I'm almost toying with the idea of buying one of these dirt cheap things and using it as a sacrifical item: https://www.aldi.co.uk/ferrex-20v-rotary-hammer-drill/p/809036556437801

Do folk reckon this would work effectively? (Maybe bodged to receive its supply via a cable from a battery on the surface?)

What about using it with an attached battery - would that be safe?

Think you're on to a loser trying to submerge that one, a small compressor and pneumatics ? (noise could be a problem)

 

[PeteHall]

maxf of this parish has a prototype that he's working on. Might be worth dropping him a message.

 

[Steve Clark]

Cheap air drill (£30-50) driven from a cylinder? Adjust the reg IP down to about 6bar.

 

[digscaves]

PM sent

 

[Leclused]

An other option is a airpresseare

Think you're on to a loser trying to submerge that one, a small compressor and pneumatics ? (noise could be a problem)

or with 300bar cilinder and no compressor. I known a few divers here in belgium who work that way far underwater.

 

[Pitlamp]

Pete - do you mean Max is working on a battery drill? Or is his project using compressed air?

Steve and Bograt - we've had an offer of a compressed air drill. Yes, noise is a problem. But we've got around this in the past by making a sound absorbing sonic screen (as used with air chisels at Malham in the past). I've seen something elsewhere on this forum not so long ago suggesting SDS hammer drills do work underwater. If the drill's cheap enough, maybe it's worth a punt?

Thanks Leclused - using cylinders may not be ideal because air tools quickly exhaust the air supply. Then again, it may be betterthan no drill.

 

[PeteHall]

Pete - do you mean Max is working on a battery drill?

Yes, battery drill. Not sure if it's ready for action yet though.

 

[Pitlamp]

Aha - now that is interesting. You've got my email address Pete - could you pass it on to Max and ask him to get in touch directly?

 

[Duncan Price]

Thanks George - but probably not practical in this particular location.

I'm almost toying with the idea of buying one of these dirt cheap things and using it as a sacrifical item: https://www.aldi.co.uk/ferrex-20v-rotary-hammer-drill/p/809036556437801

Do folk reckon this would work effectively? (Maybe bodged to receive its supply via a cable from a battery on the surface?)

What about using it with an attached battery - would that be safe?

Looks identical to the Lidl job I bought several years ago for £50. I have used it for drilling shot holes - it does only one. Having tested it I wish i'd bought two (for the spare battery and drill when i break the latter). I am in the market for a new hammer drill and am tempted to buy 2 or 3 (I'll have a look at my Lidl "Parkside" job and see if they match) - just noticed does not include battery and charger - so might just score some batteries.

 

[Pitlamp]

Thanks Duncan - do you mean you've used it to drill holes underwater?

 

[Duncan Price]

Thanks Duncan - do you mean you've used it to drill holes underwater?

No but from bitter experience flooding the batteries is not good for them - the drill might be OK (I didn't flood that and have known others who have dived drills which still work). If you are going down this route then a more water resistant power supply might be advised.

 

[Pitlamp]

Thanks - that's exactly what I was thinking; battery on the surface and a short cable feeding the actual drill.

 

[Rob]

Pelicase drill batteries are common and very easy to make dive proof for shallow depths

 

[SamT]

In my experience of flooding drills/batteries. Its not a case of the drill working or not, I'm pretty sure an electric motor will work whilst flooded. Its more a case of the circuit boards that sit within the batteries and the drill, that provide 'overload' protection or speed/trigger control and that sort of thing, short circuiting and frying the electronic components that stops it working.

 

[Pitlamp]

Rob - thanks; agreed. But the site in question is only 3 or 4 metres into the sump, so the battery could easily be left on land. Sam - thanks; yes, I'm sure you're right. But if the above was the situation, it'd only be the drill electronics we'd need to worry about. Worst case scenario is that it kills the drill (it's not going to cause a major fire in a sump). Maybe possible with a very old / sacrificial drill - or even a dirt cheap new one from Lidl / Aldi?

Here's a picture of the site. There is a thin airspace overhead (i.e. it's extremely shallow). What looks like the roof is merely a reflection; the real roof is very dark and is only about 20 mm above the water surface. You can see that the smaller slab to the right has suffered some abuse. We managed to jack the two apart to where they are now before both jammed. What we want to do is drill a line of 14 mm holes in the larger left hand slab, then use plugs & feathers to split it. Even chamfering just 100 mm off it would greatly help. We've been passing over this for a year with never more than 2 x 7 litre tanks on. I suspect that soon we'll need to get a lot bigger tanks through this restriction.

Does anyone have an old model of an SDS drill they never use (due to batteries knackered or superseded by a far newer / more efficient model) who might be willing to donate it to the cause? Maybe an old Bosch 24VRE, which has fairly unsophisticated electrics? I gave two away myself recently, as they were redundant (fool that I am!)

 

[cavemanmike]

I’ve got an old sds you can have if you can get it picked up from north Wales

 

[Pitlamp]

Thanks Mike - that may well do the trick!

I know someone involved in N Wales cave rescue team who is also in my club. Are you involved? Maybe best if you send a PM with more specifics about where you are / who you cave with?