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Old 05-01-2012, 02:57 PM   #61
Oct 2010
Posts: 243
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I figured since I saw my old thread resurrected I would throw the experiences I had after reading it in:

Since my original post I've drilled 10-15 holes in flat sided pots and keggles. The best advice was, indeed, to go slowly with a lot of pressure. I used cutting oil and dipped the entire bit into it every minute or so. This was sufficient to cool it.

You should be seeing 'ribbons' of material as the bit cuts, not flakes or powder. This is a good sign that you are moving slowly enough and not over-hardening the metal, as well as applying the right pressure.

I did use a corded drill, if that means anything.

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Old 05-01-2012, 05:12 PM   #62
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Bobby_M's Avatar
Aug 2006
Whitehouse Station, NJ
Posts: 23,384
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Just for good measure and future readers, I'm pasting in the text on my instructions page on drilling stainless. This is collective knowledge from a couple years of drilling for other people and supporting customers on their own projects.

Drilling stainless steel is a tricky maneuver if you haven't done it before but you'll get through it if you take your time and heed all warnings and tips here.
Lay the pot/keg on its side on a piece of cardboard or old carpet on the floor. Line the interior of the pot/keg with a rag, newspaper or a towel to catch lubricant and shavings for easier cleanup.

The first step is to make a tiny divot or depression at the centerpoint where you intend to drill. A pointed center punch and hammer is preferred but if you don't have one, you can use a 10 penny nail. This keeps the bit from wandering across the surface. We recommend first drilling a "pilot" hole of approximate 1/8". Step bits are not great at making that first piercing cut.
Fill a shot glass or similar sized cup with vegetable oil, chuck the step bit into your drill, dip the bit about half way into the oil, position over the 1/8" predrilled hole and apply a firm pressure when you start the drill. After you reach each new step on the bit, stop. Dip the bit back into the oil and let it drip off before drilling the next step. Don't make the mistake of overdrilling the diameter. The WL bulkhead and any other 1/2" NPT penetrations require a 7/8" hole.
While you're drilling, it's best to have someone help by holding the vessel stable. Hold the drill firmly and even prop the back of the drill against your thigh if you can so that if the bit grabs and tries to rotate the drill motor in your hands, you don't hurt your wrists.

Technique Tips and Tools:
The general mantra for drilling stainless is heavy pressure and slow speed. As the step bit turns against the work, it should be slicing a thin ribbon of material away the entire time. If the bit is spinning but NOT cutting, you run the risk of work hardening the stainless which is wear the bit down almost immediately. One of the biggest problems people have with this job is that their dril does not have enough low speed torque to allow for the pressure required to be applied. In other words, if you push as hard as you should be, some drills bog down. The user will try to overcome this problem by running the drill faster. Stop, stop.... No one likes to admit defeat but you may want to ask a friend or neighbor to borrow their drill. A 12 volt or higher cordless drill/driver that is multiple speed adjustments is highly recommended. The reason these work so well is that their speed adjustability is done with gearing, not a variable trigger squeeze. The low RPM setting provides a LOT of torque while keeping the speed slow. We love the DeWalt XRP series, not that you were shopping for a new drill.

We are being extremely wordy here, but it's important because we've received a lot of complaints about how cheap and dull our step bits are. While they are not the same quality as Klein or Greenlee, those higher end bits would also fail miserably with poor technique and a drill with inadequate torque. If you do not have a high torgue/low speed drill and can't borrow one from somewhere, you'd be much better off finding a plumber or electrician that can use a 1/2" conduit punch on your pot/keg. We have drilled many many holes using these "cheap" step bits and we know for a fact that you can get at least a half dozen holes drilled before you make them paper weights.
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Old 05-02-2012, 12:44 AM   #63
megalomani's Avatar
Oct 2007
Cincinnati, OH
Posts: 178
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Thanks to everyone's advise and the good folks of BrewHardware and Bargain Fittings my pots/kettle are finally pimped.

Low RPM is the way to go for sure but as stated above you need the torque to keep the bit moving. My problems of past were related to faulty battery cell which must have caused lack of torque or my arms were too tired to apply enough pressure.

Here is the drill I bought as a replacement:

The DeWalt is likely much better. Still the Hitachi however was under $40 and had a speed control dial so you don't have to rely completely on trigger pressure. Other than brewing projects, I don't do a lot of work to need a really nice drill.

I only got a corded drill because this drill had what I was looking for and wasn't much more than a replacement battery. I don't have any application where I would need to be cordless anyway.

Thanks everyone for helping me get this done.
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