Using Air Drill Underwater

[aswetich]

Long Story:
New In-Ground 20X40 Liner pool installed two years ago. When the installer was putting in the light they broke the screw on the top of the niche that holds the light in. They guy has been unresponsive (Big Surprise in the pool industry) to fix it so I have been lookin at my options and wanted opinions.

1. Can I use a air drill to drill the center of the broken screw and then use a screw extractor ? Leave the water as is and when I am done just disasseble and re-oil the drill ?? Would a standard air drill work under water ?

2. Lower the water to the screw level and use a cordless drill ?
(I have well water and I prefer not to drain)

3. Lower the water below the complete light Niche and replace it. I have a built in Secure-a-Matic electric cover that is currently out for service that is in a recessed housing by the light that with it out makes the niche accessable.

The light has a tab that holds it in the bottom of the Niche and the screw on the top.

My cover will be out for a couple of weeks so this is my best time to resolve this issue .


Thansks

[JohnT]

I doubt an air drill would work under water. The exhaust would be restricted by the water, which might keep it from working and could be dangerous. The amount of bubbles generated by the drill would keep you from seeing anything. Oil would be introduced into the pool as well.

Lowering the water level is your best option. You might investigate if a nearby fire department has a portable tank you could pump the water into temporarily. There are large canvas tanks that are used for temporary water storage in areas where there is not much water available.

My recommendation is to use left-handed drill bits instead of an extractor. You have to drill anyway, and the left-hand bit will usually pull the screw out during the drilling process.

[Poconos]

Just a comment on the air drill....I see no reason why it wouldn't work underwater as the pressure they operate at, 100+ psi, would mean the performance certainly isn't affected by a couple feet of water. As for the oil...yup, bubbles....yup.
Al

[aswetich]

Everything you said makes sense. Don't they make a long wire like extension that you can attache to a drill ? Maybe I could use a cordless above the waterline with the lony 3' flex extenstion on the bit. If I bring the water level down to the screw I wonder what the chances are of getting it out with a left handed bit ?? Where can I get a left handed bit ? (Sears)

Thanks

[INLANDSMOG]

Just a piece of advice from an auto tech who has seen many broken bolts, if the screw or bolt was cross threaded while tightening and the head broke off, don't use an extractor, odds are it will break then you will have a piece of hardened steel embedded in your screw (not fun). The left handed drill bit is the first thing I would try, making sure you are PERFECTLY centered, if it doesn't come out, then it's time to get a tap of the same size and tap new threads, sometimes you may have to go bigger and/or a different pitch.
Good luck

[aswetich]

My light Niche is Plastic with a metal sleeve imbedded where the screw goes. Here is my latest plan.

1. Get a 90 Degree drill bit accessory. Harbor Freight $10
2. Get three 12" drill bit extentions. 3 @ $8 each = $ 24
3. Left handed bit. ($5 ??)
4. Have a buddy on the diving board with cordless drill while I push on the bit where the 90 degree drill bit accessory is.

Can I get a left handed bit at Sears ?? All I seem to be able to find are the left handed screw extractors ?? I am assuming the screw is stainless so will I need a special bit ? Any comments on my latest plan ? For $50 I think it is worth a shot .....

[Ready2swim]

There is NO REASON in the world why your air drill wouldnt work under water. It would be a lot easier to just use this method rather than have a budy holding the drill above water. (Note: if you do use this method please take pictures because I would love to see it...should be a good laugh) not to mention the safety issues with trying to coordinate your timing..."ok drill, ouch STOP"!

The air drill will work just fine, you will have a little bit of oil but most likely it wouldnt be a problem...since you are aware of harbor freight pick up a few oil pads that you can set on top of the water and it will soak up whatever residule you have in no time at all. The bubbles will be a bit of a problem but if you have a snorkel mask that would solve that problem since the exaust will be above the drill bit.

I would suggest a left hand drill bit and keep in mind you must have a steady hand or the fixture will be ruined forever.

Let us know what you decide to do...

[aswetich]

As you described the diving board method I actually could see it happing just like that and I could not stop laughing !!! I think I will try the drill in a bucket 1st (Also will get rid of the largest amount of oil) and if that works I will go for it. Plan "B" will be the "Diving Board" method and Plan "C" will be the drain down. I will be doing this tommorow so any other sugestions would be appreatated.

[Poconos]

Something else I just thought of...a Helicoil. For those that don't know it's a coil type insert that gives you the original thread when the hole is damaged. Available at auto stores. Kit comes in different thread sizes with a special size drill, tap, and an insertion tool. My only question would be the coil itself standing up to the water and chemical environment.
Al

[GHM]

I had to do a similar drilling job underwater. I just took my old Makita cordless down in the water and drilled away. Worked fine.
Afterwards I blew the excess water out with a compressor and the drill has worked fine ever since.