[euge]

I made marks on the inside of my kettle starting at 5 gallons. That's what I use now.

How did you mark it? Mine is imprinted every 2 gallons and I want it to show quarter gallon increments. Dremel?

If you have a steel kettle I wouldn't dremel it. Mine is aluminum so just a light scratch with a screwdriver- I also highlight it with a sharpie from time to time since it tends to scrub off.

I measured my kettle and figured out the volume per inches. I made my marks and then double checked it by adding a gallon at a time.

Also if you know the gallon per inch you can use a ruler to measure from the top of the kettle to the surface of the wort. This is quite accurate.

Just remember that wort expands and contracts as it heats and cools.

[tschmidlin]

The key would be to "notch" the plastic or metal rod/tube with, say, a turn of the pipe cutter or kitchen knife.  Numbering the notches is more difficult--a dremmel might be the best tool.  From personal experience, I can say that a black sharpie does NOT work.  The wort pretty much dissolves it right off of a plastic mash spoon.  All the time spent adding a gallon at a time to the BK was wasted.  Plus, black sharpie stuff got dissolved into the wort--not necessarily what one wants in the beer.

You can mark it so that you never insert anything into the wort - just hold the bottom of the spoon/dowel at the surface of the liquid and mark your increments on the handle where it meets the top of the kettle.  No need to dunk it in the wort.

[Slowbrew]

I used a small counter-sink punch to mark 1 gallon increments.  Each mark is a divot and I count down to the level of the wort (i.e. my 12 gallon kettle has eleven marks and I count down from twelve, starting at the lip, till I reach the wort).

Paul

[richardt]

A great idea, Tom.  I have a 36" plastic spoon so I may have to measure from the top of the spoon (i.e., the handle) to determine how much fluid is still in my 20 gallon BK.  At least the bottom 18 inches of my spoon ends up going into the wort to stir--so that portion won't work for measuring near the end of the boil.

[Alewyfe]

Luv, luv, luv my sight glasses. No more measuring into or out of the HLT.  Instantly know what's in the kettle and
if my calculations and or evaporation rates are right. Can't believe it took me so long to appreciate the value
of knowing where my volume is at ALL times.

[tschmidlin]

A great idea, Tom.  I have a 36" plastic spoon so I may have to measure from the top of the spoon (i.e., the handle) to determine how much fluid is still in my 20 gallon BK.  At least the bottom 18 inches of my spoon ends up going into the wort to stir--so that portion won't work for measuring near the end of the boil.

It's a trick I learned from Gordon Strong, who may have learned it somewhere else.

[hopfenundmalz]

A great idea, Tom.  I have a 36" plastic spoon so I may have to measure from the top of the spoon (i.e., the handle) to determine how much fluid is still in my 20 gallon BK.  At least the bottom 18 inches of my spoon ends up going into the wort to stir--so that portion won't work for measuring near the end of the boil.

It's a trick I learned from Gordon Strong, who may have learned it somewhere else.

Sometimes I do it that way, sometimes I don't.  When I fill I know how many marks to leave as free space for a 60 or a 90 min boil. 

[realbeerguy]

Wood dowel for the last 18 years

[bo]

Wood dowel for the last 18 years

Now you're just braggin'.

[hoser]

Notched CPVC piping would work as well andI believe is heat tolerant at boiling temps and is super cheap.  It needs to be CPVC, not PVC.  I also have a notched copper pipe as well depending on the kettle I am using.

[Pinski]

I've always heard you don't want to expose CPVC to temps over 180 dF.

[Pinski]

Luv, luv, luv my sight glasses. No more measuring into or out of the HLT.  Instantly know what's in the kettle and
if my calculations and or evaporation rates are right. Can't believe it took me so long to appreciate the value
of knowing where my volume is at ALL times.

A friend showed me to put a couple of round gaskets on your sight glass that you can roll up and down to mark your target levels.

[bo]

Although they sound like a great idea, I'd break a sight glass the first time I went to clean my converted keg.

[bonjour]

I notched my mash paddle. Multi-tasker.

This

me too

[hoser]

I've always heard you don't want to expose CPVC to temps over 180 dF.

Everything I have read says up to 200F and short term exposure up to 230F.  I never leave it in the kettle and only take quick measurements.  But, like I said, "I believe."  I have been known to be wrong once, twice.   I usually only measure my preboil kettle volume after it is run off from the mash tun.  So, I rarely expose it to boiling temps, now that I think more about my process.  I have brewed enough with my system that I have a good idea what my boil off rate and final volume should be at the end.