Problem Drilling into one of my SS pots

Hey guys,

So the last of my brewing equipment arrived today, so right after work I was eager to start building!

After opening everything and getting it laid out, I opened my new pack of 216 drill bits (titanium coated-mastercraft) and my 18V cordless drill. I grabbed my 3 in 1 and layed down my first SS pot.

I started with a 3/16" drill bit for the pilot hole, and i didn't bother using a nail punch to avoid walking. I went straight to it, threw some 3 in 1 on my drill bit and on my "x" and at a low speed I started drilling. After a few seconds I could see curls of steel coming off the drill bit. Soon enough the drill bit passed through, and I moved on to 1/4" bit (my unibit starts at 1/4" so I figured I would widen the hole first). The last step took a long time (I found out that when re coating my bit, i switched it to reverse which made the cutting slow- duhhh!), but finally it passed through. Unfortunately, my unibit only goes up to 3/4" so my 1/2" NPT fitting doesn't pass through yet, and I don't have any files good enough to widden the hole. I guess I'll just borrow a 7/8" bit from work tomorrow, so I can wait for that.

My REAL problem occured on my second pot (this is my HLT, so I'm adding a spigot, a sight glass, and a thermometer-making it the WORST pot to drill poorly). I started off with the 3/16" bit, and I decided I would use the nail punch to get everything started. The steel curl didn't come, even after 5-10 mins of drilling. Almost no cutting was visible at ALL. So, instead of spinning the bit faster (heat-nooo!) I applied more pressure. SNAP. broke a drill bit. I kept drilling, and breaking more bits. I stepped down to a 1/8" bit and snapped those too, nothing was working. I then strapped on my unibit... although it didn't snap, it wasn't working either. It seems like the bits just roll on this medal, and don't cut it. This 'SS' pot is very shiny, and looks like this would happen anyways. I'll post some pics, but if you look on the inside, you can actually see that the wall has bent inwards, revealing that this is very weak SS, and it deforms easily (I suppose making it difficult to cut).

What are your suggestions to cut this? Should I get a bit that specifically starts pilot holes? Should I try and get one REALLY sharp bit that will get the hole started, and from there I can bore it? I'm extremely frustrated and would appreciate any advice you can give me.

First pic: the first pot which drilled beatifully
second and third pic: the hole from the outside, where I am drilling from
fourth and fifth pic: The dent being made on the inside of the pot

The basic problem is the metal has work hardened and dulled the bits. You could grind a starter hole through it or use a cobalt (not cobalt coated) bit to start the hole to get through the hardened portion.

Hi

Several problems at once:

1) Drill bits dull down quickly working on stainless steel.

2) Stainless "work hardens" as you try to drill it. It can get very hard after a minute.

3) You need to keep things cool while drilling. Flooding the drill point with fluid is the norm. The normal fluids are a lot lighter than 3 in 1 oil (they boil at a lower temperature).

Greenlee punches are the other alternative for doing this. They aren't perfect, but most people have pretty good luck with them.

Bob

Is it possible that it hardened despite me not speeding up the drill bit? out of all the times I touched the bit, there were only one or two times where I actually pulled my finger away because it was hot, other than that, it stayed cool.

I also tried to start drilling a hole above this one for my thermometer, and it is also VERY hard to start. It seems as if the bits just can't make the first bite

Hi

Don't bite often means dull.

The tip of he drill is working against a *very* small area. It can harden without everything getting smoking hot. Normal stainless cutting fluids will boil and cool the bit long before it gets anything like hot to the touch (Think Tequila - no, don't use it, it's flammable ...).

Bob

I always had a generous amount of 3 in 1 on the bit and around the hole, but the bit kept getting hot anyways. I've heard of many people using 3 in 1, so it couldn't be the oil.

When I go to work tomorrow, would you suggest that I just get a 3/16" or 1/8" cobalt bit, or should I try for a set of increasing diameters up to my unibit? God I don't want this to happen again tomorrow, I just want to cut through this crap!

and I wouldn't necessarily say that not biting means a dull bit Bob (edit: I just say "often", sorry!). They cut through my first SS pot, and I used a different bit for my second one (actually, many other bits, as at least 5 broke...). They are weak, and maybe they ARE a bit dull... but if they worked on my first one they should work on the second one. I have a feeling this type of SS doesn't like to be drilled

Is there any chance your drill is low on power? People have jumped on me for saying this but I had a similar problem using a cordless drill that had a failing battery (didn't realize at the time). I also made my first hole without much difficulty. When on to the second hole I also broke several drill bits and thought maybe I had work hardened the steel. I was able to get a little divot similar to that in your picture, seemed like the bit wouldn't dig in at all after that. Couldn't even get any metal dust.

Anyway, after realizing the battery was trash I bought a new corded drill that was about the same price of a replacement battery. It was a Hitachi that has a variable speed control dial. Plugged it in and worked perfect, "like butter".

Several people told me I was drilling too fast but the bit was never even getting hot. I think you need some torque to get through. In my case I am convinced my lack of power (torque) was responsible for the headache. Several holes with the new drill seemed way too easy (even using the same bit).

it's possible that it is low on power, I'll try a fresh battery tomorrow with cobalt tips.

It still seems as though this type of medal is somewhat 'slippery', and I can heard my bits almost running around a circle when I drill. I hope a sharp bit will do the trick.

I'll post back tomorrow if things work

It may sound strange, but I've had luck using a self tapping screw to start a hole when a drill bit isn't grabbing.

Just use a regular bit to get a pilot hole started. Step bits aren't very good at making the initial hole. Even a 1/8" starter hole is fine.

carlisle_bob said:

Hi
Greenlee punches are the other alternative for doing this. They aren't perfect, but most people have pretty good luck with them.

Bob

Click to expand...

Problem is, you have to start them with a hole.

Are you sure your drill was running in the correct direction during all of this? The fact you changed bits and had the same occur makes me think you are running backwards.

I used a dremel and a diamond tip bit to make starter hole. Like butter after that!

I finally got a hole through, finally!

I used cobalt bits, and a new battery... not sure which was the issue but the combo worked!

I didn't have much time during my lunch break to finish it, but as of now I have a hole about 1/2". The unibit seems to be slowing down in terms of its cutting speed, which is a pretty big piss off. I only drill for about 30s at a time, and I touch the bit to make sure its not overheating, but sometimes it still gets hot, even through the lubricant. The bit sticks when I add too much pressure, so I think that's what it's taking so long... although I'm not sure why because this is an 18V drill.

I widened my BK so that my SS nipple fits through (its tight, kind of have to thread it through) and I was pleased with that. The only problem is that when I thread on the ball valve, and insert the silicone gasket and female adapter (for the diptube) on the inside, there is a section of the nipple that is exposed. I guess this means that I'm going to need some spacers, which I wanted to avoid.

Hopefully when I'm off work I'll be able to finish widening this hole, and can finish my thermometer and sight glass holes without a fuss.

Lubricate the cutting process as often as possible.
Continuous lube is best.
Have a friend squirt oil on the bit, as you cut.

I heard dishwashing soap works for cooling the metals. Take it slow and rest in between... the whole will happen.. the dent is probably from too much pressure/heat... lube it and take your time..

UPDATE:

Okay, so after I got home from work, I finished my first hole on my second pot, and flew threw the second one. My routine now is to use a 3/16" cobalt tip for a pilot hole, then I move on to a low pitch unibit, and finally move on to my last 7/8" unibit. It works EXTREMELY well, and takes only about 15 mins to make a hole. I highly recommend skipping all other bits if anyone wants to cut a hole in their stainless steel ALL YOU NEED ARE COBALT BITS, A FEW UNIBITS, AND DISH SOAP.

Yeah thats right, I found out that dish soap worked much better than my 3 in 1, kept the bit cool no matter how fast I tore through the medal.

Now that I'm on to my last hole, I only have one question.

I slightly over drilled one of my holes, the nipple slips clean through. When I put on my ball valve, and screw on a locknut on the inside with a silicone washer infront, I find that closing the ball valve presents a problem. What seems to happen, is that the closing motion actually rotates the whole assembly (now the ball valve isn't completely vertical). I don't think this will cause it to leak, I would just like for it to be a little more rigid.

Do you think a medal washer will provide enough friction to keep everything in place? Is this because I drilled the whole too large, or because the silicone gasket has quite a bit of give.

Any solutions are welcome Thanks everyone!

I oversized the hole in my keggle (my bad) but to stiffen it up and get a good seal I used a silicone O-ring and S.S. washer inside & outside on the nipple and snug em down good. Worked for me, but you may have to do a little work on the washer to get it to thread onto the nipple. I used a small emery drum sander on my drill for sizing the washers and the under size holes to thread the fittings in tight for good seals. Cheers

It took me 2 days to drill a 1/4 pilot hole in my SS pot and 30 seconds to step up to 7/8....good luck.

BOBrob said:

I oversized the hole in my keggle (my bad) but to stiffen it up and get a good seal I used a silicone O-ring and S.S. washer inside & outside on the nipple and snug em down good. Worked for me, but you may have to do a little work on the washer to get it to thread onto the nipple. I used a small emery drum sander on my drill for sizing the washers and the under size holes to thread the fittings in tight for good seals. Cheers

Click to expand...

This is more or less what I was thinking of doing. I was going to try and see if it was only necessary on the inside, but it might just be that it'll only work on both the outside and inside. My only reason against it is the aesthetics; I'm not a big fan of having anything else on the outside other than the spigot. On the inside, you have the silicone O-ring/gasket first, then the washer... then the locknut, correct?

Thanks!

JayMac said:

This is more or less what I was thinking of doing. I was going to try and see if it was only necessary on the inside, but it might just be that it'll only work on both the outside and inside. My only reason against it is the aesthetics; I'm not a big fan of having anything else on the outside other than the spigot. On the inside, you have the silicone O-ring/gasket first, then the washer... then the locknut, correct?

Thanks!

Click to expand...

I use a silicone O-ring/ gasket first, the washer and " pipe to compession adapter" inside. The female pipe threads to the nipple instead of the locknut; I have a short piece of S.S. pipe bent 90 deg. with a compression fitting to reach the bottom for draining. The outside washer is backed with a S.S. connector, 3 inch pipe and valve.