Accurate volume markings on a brewing kettle enables you to achieve perfect boils by easily adjusting water to wort ratio. If you don't own an expensive Stainless Steel pot with markings, there's an easy way to etch/mark them.
This is a very old technique to etch on Steel used by Bladesmiths for a very long time. My special thanks to Kurtck for posting an article on instructables on "Etching Aluminum Brew Kettle". I have made some changes in the article to allow etching Stainless Steel pots the same way here.
What you need
A Stainless Steel Kettle (Obviously)
Table Salt
Any Vinegar
9v Battery (A standard HW battery sells for Rs.22)
Piece of a long wire
Q-tips
Adhesive Stencil (Hunt your nearest craft store)
Electric tape
Process
1. Measuring the Kettle
Start filling the kettle with water in increments that you wish to have marked on your kettle. I like to mark my kettles at two liter increments to keep it easy. Eg. 2, 4, 6, 8... and so on. Put tapes at the water surface as you go.
As for me, I use a 1 liter measuring jug. To make it easier, if your container has straight walls, you can measure the gap between second and third water levels (first one doesn't count since most kettle bottoms have round edges) and repeat the measurement up the wall of the kettle. Alternative to tape, you could also use a wax colour chalk or nail polish. Just make sure whatever you use is water proof.
2. Put Stencils
Sticker or adhesive stencils are best suited for this project since they will stay firmly put and perfectly cover the vinegar during marking. If you use other options, make sure they stuck firmly and stay in place while working. Making the project a breeze or a nightmare depends highly on your ability to getting the stencils just right.
3. Mix Vinegar & Salt
Combine your vinegar and salt. A few pinches of salt to about a couple of table spoons of vinegar should suffice, the ratio isn't really important. Give it a stir to dissolve the salt. If some of the salt stays unmixed, don't sweat it.
4. Making Wire Connections
It is important that you hook the positive end of the wire to a part of your kettle. You can stick the bare wire end to the kttle handle or mouth. This connection basically completes the electric circuit allowing for the negative end connected to the q-tip eating away the tiny part of kettle it touches. No need to be concerned though; the current is so low that you can not notice it at all. You can safely touch the kettle.
5. Prepare the Qtip
With another wire, attach the negative lead to the Q-tip. The wire will need to be in direct contact with the vinegar solution, so make sure it is wrapped around the cotton head of the Q-tip. Give it a good tight twist so it will stay on as long as you want it to. I found that the wire will actually dig into the cotton so you don’t need any tape for this step.
6. Start Marking
Dip the Q-tip in your salt-vinegar solution and touch it to the place you wanna mark. Expect some sizzling and bubbling, that's our etching tool at work. It takes just a few seconds to modify the metal. You must keep the Q-tip moving. As you etch, you'll notice your Q-tip absorbing some of the metal and turning grey-dark. If you like you can change the Q-tip a few times, but in my experience that isn't really necessary.
Remember, anywhere you touch the q-tip to the kettle it will leave a permanent mark, so be careful. Maybe experiment a little on some other less visible steel surface where you wouldn't mind a couple of stains. Like bottom of a pot or inside of a lid.
There you have it folks. Happy homebrewing you all!
Etching on stainless steel surface