Trouble drilling starter hole in stainless steel pot

[lhommedieu]

I thought that I'd post this and then walk away from the problem for a while, in hopes that someone with more practical experience than me could offer some advice.

I am currently 1 hour into a project that would normally take me 10 minutes or so: drilling a starter hole for a step bit that could drill a 3/8" hole near the top of a twenty gallon stainless steel pot, I want to attach a float valve near the top of the pot and connect it to a RO water filter line. So far I am only about half of the way through to the other side, despite using a cobalt drill bit, and a piece of wood on the inside, from hole side of the pot to the other side, to buttress the pot and and add some rigidity to keep it from bending. I am thinking that my next step might be to punch a hole with a nail and short-cut the process.

It's just a stainless steel pot and I've never had this much difficulty with similar pots. Thoughts?

 

[kh54s10]

Sharp bit, slow speed, cutting oil. And patience. But when I did it it only took about 5 minutes. Very thick SS pot.

 

[FloppyKnockers]

^^ Beat me to it. Sloooooooooow and cutting oil (or WD-40) are key.

 

[Stillraining]

SS work hardens easily..that's whats happen to you now. so now as mentioned very sharp high quality bits, slow and once its cutting dont let it stop and just spin, keep pressure on and keep it cutting..

 

[imasickboy]

It's possible you already overheated the bit and killed the sharp edges.

 

[lhommedieu]

Thanks for your replies. It's a thick pot. Possibly I hardened the steel by drilling at too high a speed. I'm using oil but I definitely did not drill at a very slow speed. I'll see what happens tonight and get a new bit tomorrow if I can't make any progress.

 

[wilserbrewer]

What kind of drill are you using?

You want low speed with a fair amount of down pressure. The bit should be cutting a spiral of steel, not spinning fast making steel dust.

 

[patthebrewer]

SS work hardens easily..that's whats happen to you now. so now as mentioned very sharp high quality bits, slow and once its cutting dont let it stop and just spin, keep pressure on and keep it cutting..

What he said....I've accidentally work hardened SS a few times. When I've done that I've switched to a slightly larger diameter bit, then the one I was using, and as has been mentioned cutting oil (mobil one works great), slow rpms, and keep the pressure up

 

[Carlscan26]

I had the same experience with a Concord pot - they are apparently an alloy that is a harder version of SS than 304. After breaking several cobalt and titanium bits (the titanium ones were old but the cobalts were brand new) I knocked on my neighbor's door (he has a small shop in his garage) and he pulled out a carbide bit and it was ridiculous how fast he got the hole made. I was kicking myself for not asking him sooner. From there I was able to use my step bits just fine but I've never had such a hard time getting a starter hole made. I thanked him with a few bottles of my IPA. Oh and cutting oil is a huge pain to clean up but makes such a difference imo.

 

[MaryB]

Use real cutting oil, not WD40 or car oil. It has very different properties to keep bits from dulling and to transfer waste away from the bit.

 

[stz]

I always use a knockout punch, the type you tighten up with a spanner. While of course there are plenty of ways to skin the cat in the workshop some prove better than others and this has to be the best ratio of easy/finish/price for me and I would recommend it to anybody who already doesn't know what they are doing.

Got a hand drill and very good (v.expensive in large sizes) or brand new average HSS (they'll stay good for a hole or three) bits and feel able to supply adequate feed pressure without leaving duelling scars all over your shiny stainless baby and don't mind a few triangular holes due to harmonic slop in the chuck? Got a good stepped bit in the right size to de-burr ready to wear out? You are all ready to spend more time to hopefully do a comparable job to a punch and a half round file. Larger holes straight up drilled by hand usually tear and practically always look super ugly. Of course if you've the equipment and experience to overcome all these issues then you fall in the category of already knowing what you are doing though 20gal pots aren't the easiest thing to get clamped down under the drill press.

Of course you've still got to drill a pilot for the knockout, but a quick tap with a centre punch to give it something to start on and those smaller HSS bits are cheap enough to be disposable.

 

[patthebrewer]

Use real cutting oil, not WD40 or car oil. It has very different properties to keep bits from dulling and to transfer waste away from the bit.

Yup... wise words. Not sure if the your mention about car oil was meant for me....but I would totally agree with you. I would just clarify that Mobile One makes a special cutting oil, to which I was refering

 

[MaryB]

Mobile One all alone is car oil lol

Yup... wise words. Not sure if the your mention about car oil was meant for me....but I would totally agree with you. I would just clarify that Mobile One makes a special cutting oil, to which I was refering

 

[MaryB]

I drilled 6 holes with a hand drill and step bit after drilling a pilot hole. No issues whatsoever and that drill had a LOT of use on it!

I always use a knockout punch, the type you tighten up with a spanner. While of course there are plenty of ways to skin the cat in the workshop some prove better than others and this has to be the best ratio of easy/finish/price for me and I would recommend it to anybody who already doesn't know what they are doing.

Got a hand drill and very good (v.expensive in large sizes) or brand new average HSS (they'll stay good for a hole or three) bits and feel able to supply adequate feed pressure without leaving duelling scars all over your shiny stainless baby and don't mind a few triangular holes due to harmonic slop in the chuck? Got a good stepped bit in the right size to de-burr ready to wear out? You are all ready to spend more time to hopefully do a comparable job to a punch and a half round file. Larger holes straight up drilled by hand usually tear and practically always look super ugly. Of course if you've the equipment and experience to overcome all these issues then you fall in the category of already knowing what you are doing though 20gal pots aren't the easiest thing to get clamped down under the drill press.

Of course you've still got to drill a pilot for the knockout, but a quick tap with a centre punch to give it something to start on and those smaller HSS bits are cheap enough to be disposable.

 

[lhommedieu]

I had the same experience with a Concord pot - they are apparently an alloy that is a harder version of SS than 304. After breaking several cobalt and titanium bits (the titanium ones were old but the cobalts were brand new) I knocked on my neighbor's door (he has a small shop in his garage) and he pulled out a carbide bit and it was ridiculous how fast he got the hole made. I was kicking myself for not asking him sooner. From there I was able to use my step bits just fine but I've never had such a hard time getting a starter hole made. I thanked him with a few bottles of my IPA. Oh and cutting oil is a huge pain to clean up but makes such a difference imo.

Thanks to everyone for your input. I'll try again when I'm back at my house with a carbide bit and cutting oil. I'm not in a hurry but I would like to get my RO system back up and running so I can brew again soon.

 

[lhommedieu]

Just an update:

No luck with the hardened drill bit.

I ordered a 1/16" carbide drill bit and a recommended cutting oil, and used the drill at the lowest setting that I could manage. No problem getting through with firm, but not too heavy pressure (I was worried that too much pressure would snap the bit in the hand drill).

A 1/8" bit is in the mail, and then after I have a starter hole, I'll see if a step drill bit can get the work done.

Links to the products I've used/will be using are below:

https://www.amazon.com/gp/product/B002M8OPBS/?tag=skimlinks_replacement-20

https://www.amazon.com/gp/product/B003JTI7W2/?tag=skimlinks_replacement-20

To be continued...

 

[kh54s10]

I think on one of the holes I drilled I used a punch awl to make a starter "indent" then just used the step bit. No starter "hole". But.... That was 4+ years ago..... I probably also used my drill press.

 

[lhommedieu]

No problem with the 1/8" carbide bit and oil (slow speed, medium-hard pressure). The pot just laughs at my step bit.

Looks like I'll move up to 1/4" and then 3/8" in carbide....

 

[lhommedieu]

Done. I ended up expanding the 1/8" hole with a 1/4" carbide drill bit. I knew that my step bit wasn't going to work at this point, so I was going to buy a 7/16" carbide bit, from the same source, above, but at $80 the cost was prohibitive. I went to the hardware store to find a carbide-tipped bit, but couldn't find one. I ended up buying a tungsten bit in the same size.

The difference between a carbide bit and a tungsten bit was huge. In retrospect, a carbide bit would have been a lot easier, but the tungsten bit got the job done with a lot of patience and a lot of cutting oil. I think the carbide bit would have taken 1/10th of the time, based on my experience with the smaller bits. I cleaned the hole up with a Dremel grinder bit and the float valve fits in perfectly.

 

[timdillon36]

I don't mind a few triangular holes due to harmonic slop in the chuck? .

The triangular holes are due to the diameter of the drill bit used and the thicknes of the material you are drilling as well as the angle of the point on the bit.

Basically if the point of the bit breaks through the material before the OD of the bit has made contact there is not a center point or an outside hole to keep it centered.


By hand it is worse but even clamped down this will still happen.

 

[Mr_McGibblets]

OK, I have to add my two cents to this. Followed everyone's advice here as well as many other threads found in this forum and other places on the web.

I bought a new 62-quart Bayou Classic and spent HOURS trying to drill holes into the damn thing using a new Milwaukee Cobalt bit (1/8") and Tap Magic cutting oil with my cordless drill set to "Low" and at a slow speed, to no avail. (My wife and I joked that if North Korea launched nukes aimed for us here in So Cal, I could just put the damn pot over my head and survive it, no problem.)

Some said to try Dewalt Cobalt bits instead. So I bought 3 of those -- same result. The most I could get was a small dimple even though I had the pot on floor and I was pushing with all my might (I broke three 1/16" bits trying to start with a smaller diameter).

Anyway, the wife said, "Hey, why not use the new Dewalt hammer drill you just bought for recent flooring install?" Of course, I said, "No, it spins too fast, plus that's for drilling in concrete -- and remember, you should always use the right tool for the job!" Besides, I had already tried using it the week prior (although I had it on the work bench and wasn't pushing down very hard). I was too afraid to "work-harden" the spot.

Needless to say, I tried the hammer drill again (with the Dewalt bit), with the pot on the floor, with cutting oil, but this time I pushed with almost all my weight AND I let the damn thing spin at TOP SPEED in HAMMER DRILL mode.

Guess what????

In less than a minute, the bit went right though the pot! In fact, I was able to do three other holes the same way and with the same bit.

Side note: The Dewalt cobalt bits are rated "2X" whereas the Milwaukee cobalt was rated "10x". Guess which one broke! Yep, the Milkwaukee.

TL;DR

Dewalt HAMMER DRILL + Dewalt 1/8" Cobalt bit + Tap Magic Cutting Oil + BRUTE force + HIGH speed = great success!

 

[kh54s10]

Dewalt HAMMER DRILL + Dewalt 1/8" Cobalt bit + Tap Magic Cutting Oil + BRUTE force + HIGH speed = great success!

That might have worked but I would not suggest doing it. Slow speed is what you want.

I used a cheap step bit set from Harbor Freight. $20 for 2 bits (only used the larger one) and drilled 4 holes, using only firm pressure, in less than an hour including the time to determine where to drill

 

[Mr_McGibblets]

That might have worked but I would not suggest doing it. Slow speed is what you want.

I used a cheap step bit set from Harbor Freight. $20 for 2 bits (only used the larger one) and drilled 4 holes, using only firm pressure, in less than an hour including the time to determine where to drill

I was using a very slow speed with the new bit and after 20 minutes, I gave up. No progress. That said, I did have a HF step bit from my making previous kettle, but this time, I invested in an Irwin step bit and after getting the 1/8" holes drilled, the Irwin one was so much faster/sharper/better.

 

[kh54s10]

I was using a very slow speed with the new bit and after 20 minutes, I gave up. No progress. That said, I did have a HF step bit from my making previous kettle, but this time, I invested in an Irwin step bit and after getting the 1/8" holes drilled, the Irwin one was so much faster/sharper/better.

Since I was only buying my step bits for 4 holes, and Harbor Freight is only about 5 minutes from my house I got them because of the price...

 

[Nmnbrewer]

If you were trying to drill into the same spot you were merely hardening the stainless steel even further. Just a thought.

 

[NeoBrew]

Just to put some quantification on what "slow" means. You would ideally have a drill that can get down to 200-300 rpm to drill into stainless. And also put quite a bit of pressure on the bit. That is how you can get the spirals of metal out. I'm working on a stainless steel stair railing right now. I am using a mill/drill in my shop to make the holes. Anything faster and I start getting lots more smoke and chips instead of spirals. I also touch up my bits on a Drill Doctor every 6-7 holes. That makes an enormous difference. With that setup I'm able to make a hole through 3/16" stainless in under 2 minutes.

Since most of us don't have access to a true low speed drill, you can certainly go faster. Even the "low speed" Harbor Freight drill that I use to run my grain mill runs at 500 rpm. Most hand drills are a lot faster.

My last experience drilling a hole in a pot (before I had access to this equipment) was filled with expletives! I work hardened it with the starter bit, got the triangle hole with a 1/4" bit that I used to enlarge the starter hole, and then finally work hardened the hole (multiple steps) as I enlarged it with a step bit.

I made it through that by taking a night to sleep on it, using a file to sharpen the edges of the step bit up, and putting all of the weight I could onto the drill at as low a speed as it would run. Also, plenty of cutting oil.

 

[Morrey]

I find the best technique is to keep the bit(s) cool with water. I got this tip from Blichmann's CS rep when I installed a whirlpool arm. He suggested frequently dipping the pilot bit and step bit into a water bath to prevent overheating which dulls the bit.

I took it one step further and had a helper spritz water continually on the kettle surface and drill bit as I slowly drilled in. I did two Blichmann kettles this way and only took a few minutes until hole was completed.

 

[augiedoggy]

I had a hard time with my bayou 1062 kettles (not sure what grade of stainless they are but they are not 304 as discussed in the threads about induction) until I switched drills. I was using my variable speed 3/8 dewalt corded drill.. Once I switched to my cordless ryobi and used it in the slower screw mode which let me go at a much slow rpm the harbor freight step bit was able to drill all 12 holes in the three kettles with no issues very quickly... I did use wd40 as cutting oil which is not ideal. bI did get lots of stainless metal spiral shavings so it was cutting quickly., had to reverse it a couple times because the bit would jam right up it cut so deep.

 

[Bilsch]

For drilling brewing equipment I use a squirt bottle of 90% isopropyl alcohol as the coolant. Works very well, keeps the bits nice and cool and there is no clean up worries. You have to apply continuously so a helper is handy to have. Oh and don't do this in an enclosed space, or while smoking.

 

[Mr_McGibblets]

If you were trying to drill into the same spot you were merely hardening the stainless steel even further. Just a thought.

I apologize if I wasn't clear in my previous post. When I thought I had work-hardened the initial spot, I started another one about 6" away. Same result. Just spins and spins.

Just to put some quantification on what "slow" means. You would ideally have a drill that can get down to 200-300 rpm to drill into stainless. And also put quite a bit of pressure on the bit. That is how you can get the spirals of metal out. I'm working on a stainless steel stair railing right now. I am using a mill/drill in my shop to make the holes. Anything faster and I start getting lots more smoke and chips instead of spirals. I also touch up my bits on a Drill Doctor every 6-7 holes. That makes an enormous difference. With that setup I'm able to make a hole through 3/16" stainless in under 2 minutes. Since most of us don't have access to a true low speed drill, you can certainly go faster. Even the "low speed" Harbor Freight drill that I use to run my grain mill runs at 500 rpm. Most hand drills are a lot faster. My last experience drilling a hole in a pot (before I had access to this equipment) was filled with expletives! I work hardened it with the starter bit, got the triangle hole with a 1/4" bit that I used to enlarge the starter hole, and then finally work hardened the hole (multiple steps) as I enlarged it with a step bit. I made it through that by taking a night to sleep on it, using a file to sharpen the edges of the step bit up, and putting all of the weight I could onto the drill at as low a speed as it would run. Also, plenty of cutting oil.

I was using my Craftsman 17586 NEXTEC Drill/Driver set to LO speed which maxes out at 400 RPM. I was barely pulling the trigger making it around 100 RPM and using a brand new Colbat 18/" drill bit form Dewalt + Tap Magic Cutting Oil.

I find the best technique is to keep the bit(s) cool with water. I got this tip from Blichmann's CS rep when I installed a whirlpool arm. He suggested frequently dipping the pilot bit and step bit into a water bath to prevent overheating which dulls the bit. I took it one step further and had a helper spritz water continually on the kettle surface and drill bit as I slowly drilled in. I did two Blichmann kettles this way and only took a few minutes until hole was completed.

I was using Tap Magic + a desk fan blowing on the area at the same time.

I had a hard time with my bayou 1062 kettles (not sure what grade of stainless they are but they are not 304 as discussed in the threads about induction) until I switched drills. I was using my variable speed 3/8 dewalt corded drill.. Once I switched to my cordless ryobi and used it in the slower screw mode which let me go at a much slow rpm the harbor freight step bit was able to drill all 12 holes in the three kettles with no issues very quickly... I did use wd40 as cutting oil which is not ideal. bI did get lots of stainless metal spiral shavings so it was cutting quickly., had to reverse it a couple times because the bit would jam right up it cut so deep.

What bit did you use? Do you recall. Anyway, yes, it was on my new Bayou Classic 1060 pot. I swear that thing is made from titanium or something. I even tried to drill another just 3" away from the rim of the pot (to install a whirlpool arm) with almost all my weight and the rim barely flexed! Whatever Bayou Classic uses, it's really hard & thick stainless!

 

[Justintoxicated]

I use a punch, drill press, cutting oil, cobalt bit. Then I switch to a punch to get a nice clean hole.
This is the punch I use, it's cheaper to get the slightly larger one, but I find this one is the "correct" size for most 1/2" fittings.
https://www.amazon.com/gp/product/B002NQWZWU/?tag=skimlinks_replacement-20

Sand the edges to deburr, wash with dawn to remove the oil and your done.

my Bayou Classic has been punched as well. the 90 degree street elbows are great on the inside of this pot, and flow better, and have less deadspace in the bottom than my SS brewtech since I was able to put it right where I wanted it!

 

[augiedoggy]

I apologize if I wasn't clear in my previous post. When I thought I had work-hardened the initial spot, I started another one about 6" away. Same result. Just spins and spins.



I was using my Craftsman 17586 NEXTEC Drill/Driver set to LO speed which maxes out at 400 RPM. I was barely pulling the trigger making it around 100 RPM and using a brand new Colbat 18/" drill bit form Dewalt + Tap Magic Cutting Oil.



I was using Tap Magic + a desk fan blowing on the area at the same time.



What bit did you use? Do you recall. Anyway, yes, it was on my new Bayou Classic 1062 pot. I swear that thing is made from titanium or something. I even tried to drill another just 3" away from the rim of the pot (to install a whirlpool arm) with almost all my weight and the rim barely flexed! Whatever Bayou Classic uses, it's really hard & thick stainless!

$18 HF step bit... the one that comes in the 2 pack of 2 sizes... I had the same issue until I swapped drills.

I did since find the punch kit at HF and bought that to punch holes in my metal brucontrol control panel... it would have likely been easier to use with the kettles too but you still need a starter hole.

 

[Mr_McGibblets]

I use a punch, drill press, cutting oil, cobalt bit. Then I switch to a punch to get a nice clean hole.
This is the punch I use, it's cheaper to get the slightly larger one, but I find this one is the "correct" size for most 1/2" fittings.
https://www.amazon.com/gp/product/B002NQWZWU/?tag=skimlinks_replacement-20

Sand the edges to deburr, wash with dawn to remove the oil and your done.

my Bayou Classic has been punched as well. the 90 degree street elbows are great on the inside of this pot, and flow better, and have less deadspace in the bottom than my SS brewtech since I was able to put it right where I wanted it!

$18 HF step bit... the one that comes in the 2 pack of 2 sizes... I had the same issue until I swapped drills.

I did since find the punch kit at HF and bought that to punch holes in my metal brucontrol control panel... it would have likely been easier to use with the kettles too but you still need a starter hole.

I see!

FWIW, on that note, to anyone reading this, please do NOT use the Knockout Punch Kit from Harbor Freight to punch holes in your kettle.

Since it is a conduit punch kit, the holes will be slightly too large and they will leak like crazy. I made this mistake on my first kettle for both my element mount and my 1/2" NPT bulkhead. I was forced to track down thicker O-rings to solve the problem.

For my new kettle, I used Greenlee radio knockout punches instead which are the proper diameter. Therefore I could use regular O-Rings without leaks.

• Greenlee 730BB 1-1/4" (31.8 mm) for Camco element
• Greenlee 730 13/16" Round Radio Chassis Punch for 1/2" NPT (Weldless bulkhead, thermometer, and "Spin Cycle" whirlpool arm from BrewHardware.com)

Here are some photos of the final product!

 

[Mr_McGibblets]

Tested my new RipTide pump yesterday.

[ame]https://www.youtube.com/watch?v=kkBHIEwmqRA[/ame]

 

[Justintoxicated]

Tested my new RipTide pump yesterday.

https://www.youtube.com/watch?v=kkBHIEwmqRA

Nice work! Is that a 120v heating element? Does it take long to boil?

 

[RichBenn]

I use a punch, drill press, cutting oil, cobalt bit. Then I switch to a punch to get a nice clean hole.
This is the punch I use, it's cheaper to get the slightly larger one, but I find this one is the "correct" size for most 1/2" fittings.
https://www.amazon.com/gp/product/B002NQWZWU/?tag=skimlinks_replacement-20

Sand the edges to deburr, wash with dawn to remove the oil and your done.

my Bayou Classic has been punched as well. the 90 degree street elbows are great on the inside of this pot, and flow better, and have less deadspace in the bottom than my SS brewtech since I was able to put it right where I wanted it!

Oh the punch (i have that exact one) is amazing! Perfect holes through stanlless fast and easy. Greenlee makes high quality stuff.

I had two Bayou pots, did two 120V elements on one with a stepbit. Also did a panel before I got the punch. What I will say for drills is fresh bits, lubricant, pressure, and slow speed. A drill press is ideal. My last drilled hole was difficult as the starter and step bit had been dulled from prior use. Takes little to dull the bits or harden the stainless.

 

[Mr_McGibblets]

Nice work! Is that a 120v heating element? Does it take long to boil?

220V. Takes about 20 minutes to bring ground temp water to full boil.

You can see details of my setup here (note: this is from last year and I've made quite a few changes/improvements since).

[ame]https://www.youtube.com/watch?v=lOK0h97D1RY[/ame]

 

[CTS]

For what its worth I had some new but cheap bits that did nothing for the stainless kettle, small cut and an indent at most. I tried for 2 hrs and figured I hardened the steel even though I was probably cutting at 200 rpms with lots of cutting oil.

Someone had mention in one of the many threads to use a masonry bit to drill it out but that idea was shot down fairly fast. I found a youtube video that mentioned the same thing. So i found a masonry bit and drilled the hole without problem, worked amazing with lots of oil and about 300 rpm. Then used a step bit to cut out a 1 1/4 hole for a heating element. Took about 2 min start to finish. Going to use the same method for the 2 remaining holes.

Hope this helps someone.