How to add permanent volume marking to a kettle

[Ralph]

This is pretty sweet!

http://imgur.com/a/dCvS5

[Barry]

Nice, thanks Adam!

[Jamie McQuillan]

I just did this and it worked well. I did 5 L markings up to 20 L then 2 L after that. Takes a little bit of gentle scrubbing, and a couple of cotton bud changes, but my battery is not new, I borrowed it out of a guitar pedal. I didn't bother with numbers, it's too easy to count down from the top and it seemed more trouble than it is worth. Took me about 1.25 h. 

[Barry]

Sounds good, got any photos?

How did you mark and how did you measure volumes?

[Jamie McQuillan]

Yep, here it is, a little rough around the edges but good enough in a cheap pot.

I used a 2 l measuring jug and checked I was in the ball park using a set of bathroom scales. The 5 L marking were all 5 kg intervals. I placed thin strips of insulation tape above the water line for each interval and then went back when the pot was empty and marked out little rectangles in a straight-ish line. I think if I you wanted to be fancy you could use a strip of clear adhesive plastic , mark the volumes, remove it cut out nice markings, the put it back in the same place to etch. 

I'm not sure about the need to passivate as surely the etching has made the metal very clean and  will therefore re-passivate itself. I found this in Palmer:

Appendix B - Brewing Metallurgy

B.1 Passivating Stainless Steel

A situation that often comes up is, "Hey, my stainless steel is rusting! Why? What can I do to fix it?"

Stainless steel is stainless because of the protective chromium oxides on the surface. If those oxides are removed by scouring, or by reaction with bleach, then the iron in the steel is exposed and can be rusted. Stainless steel is also vulnerable to contamination by plain carbon steel, the kind found in tools, food cans, and steel wool. This non-stainless steel tends to rub off on the surface (due to iron-to-iron affinity), and readily rusts. Once rust has breached the chromium oxides, the iron in the stainless steel can also rust. Fixing this condition calls for re-passivation.

Passivating stainless steel is typically accomplished in industry by dipping the part in a bath of nitric acid. Nitric acid dissolves any free iron or other contaminants from the surface, which cleans the metal, and it re-oxidizes the chromium; all in about 20 minutes. But you don't need a nitric acid bath to passivate. The key is to clean the stainless steel to bare metal. Once the metal is clean, the oxygen in the atmosphere will reform the protective chromium oxides instantly. The steel will nearly as passivated as if it was dipped in acid. Nitric acid passivation creates a more chromium-rich passive surface, but is not necessary for brewing use.

To passivate stainless steel at home without using a nitric acid bath, you need to clean the surface of all dirt, oils and oxides. The best way to do this is to use an oxalic acid based kitchen cleanser like those mentioned above, and a non-metallic green or white scrubby pad. Don't use steel wool, or any metal pad, even stainless steel, because this will actually promote rust. Scour the surface thoroughly and then rinse and dry it with a towel. Once you have cleaned it to bare metal it will re-passivate itself.

If you have straw-colored or bluish tinted oxides on the stainless from welding or soldering, it should be cleaned off with a scrubby and cleanser before use. The colored oxides are not passive and will lead to rusting of the stainless steel if not cleaned. You should not have to do this procedure more than once, but it can be repeated as often as necessary.

[Adam Thomas]

Handy calculator here:

http://manskirtbrewing.com/Calculators.aspx#kettlevolume

If you use that calculator rather than measuring water into the pot, you don't have the issue of how to mark the inside when it's wet!

With your markings you need to decide whether you want them accurate for hot liquid, cold liquid, or somewhere between.  Cold occupies 4% less volume than boiling hot.  So if you are wanting to know how much water is in the pot ready for heating for mashing or sparging, then use the cold water calculation.  If you are more interested in how much boiling wort you have, use the heated water calculation.

[Barry]

Holy crap that calculator is everything I've been looking for in life.

So many google searches leading to nothing, hoping to find exactly that. THANK YOU.

Cheers for posting the photo @hophound. Worked well eh.

[paul m]

I can't imagine the utilikilt skirt thing will catch on. I'm probably wrong though. I did check there is no brewing skirt!

[Barry]

HLT, done.

Hard to tell from the blurry crap photo but all the lines are 1mm tall, litre increments. Turned out awesome.

[Jamie McQuillan]

Awesome job. Did you use the sticker cutter in the end? Who need a sight glass eh. 

[Barry]

Yeah, finally got the artwork to cut properly. Ended up having to draw it in the machine's software package, pretty torturous.

But once the artwork was right it worked really well, so simple.

[Darren Wood]

Wow! That's amazing—great job :)

[Scott H]

Damn Barry. That looks mint.