FAQ: Aluminum Pots for Boil Kettles? - Page 34 - Home Brew Forums

Register Now!
 Home Brew Forums > FAQ: Aluminum Pots for Boil Kettles?

03-19-2013, 02:20 AM   #331
Indian_villager
Recipes

Apr 2010
Claymont, Delaware
Posts: 473
Liked 44 Times on 36 Posts

Well. I just bought a 40qt aluminum pot and am putting a 1500w element to supplement my stove. And a drain valve. It is my own fault for not looking up the galvanic corrosion issue. But reading above puts me at a bit of ease.

03-27-2013, 09:14 AM   #332
MrIPA
Recipes

Mar 2013
Posts: 26
Liked 1 Times on 1 Posts

I havent been able to find any definitive information on this in off the SS vs Al pot discussions. But do you think there is any noticable difference in propane usage given the fact that the thermal conductivity of Al is so much better than SS. For reference the conduction coefficient of Al is 250W/mK where SS is only 16W/mK

Found this on the internet though

Example - Conductive Heat Transfer through a Aluminum versus Stainless Steel Pot
The conductive heat transfer through a pot wall can be calculated as

q / A = k dT / s

where

q / A = heat transfer per unit area (W/m2)

k = thermal conductivity (W/mK)

dT = temperature difference (C)

s = wall thickness (m)

Conductive Heat Transfer through Aluminum Pot Wall with thickness 2 mm and temperature difference 200C
q / A = 250 (W/mK) x 200 (C) / 2x10^-3 (m)

= 25000 (kW/m2)

Conductive Heat Transfer through Stainless Steel Pot Wall with thickness 2 mm and temperature difference 200C
q / A = 16 (W/mK) 200 (C) / 2 10-3 (m) = 1600 (kW/m2)
__________________
Primary 1: Flying Carpet Pale Ale
Primary 2: None
Secondary: None
Keg1: Widmer Bro's O'Ryely IPA clone
Keg2: Granada IIPA (AKA: "Hop Soup")
On Deck: More IPAs of course...

03-27-2013, 03:58 PM   #333
SpikeBrewing

Recipes

Jul 2011
Milwaukee, WI
Posts: 921
Liked 134 Times on 92 Posts

Well most Al kettles are 4-6mm thick and most SS kettles are .8-1.2mm thick so here's the updated #'s:

Conductive Heat Transfer through Aluminum Pot Wall with thickness 5 mm and temperature difference 200C
q / A = 250 (W/mK) x 200 (K) / 5x10^-3 (m)

= 10000 (kW/m2)

Conductive Heat Transfer through Stainless Steel Pot Wall with thickness 1 mm and temperature difference 200C

q / A = 16 (W/mK) 200 (K) / 1x10^-3 (m)

= 3200 (kW/m2)

So the aluminum will conduct heat in at a rate 3 times more than the stainless BUT it will also conduct heat out 3 times quicker too. Since there is more wall area than bottom area the heat lost may equal out the Al and SS or Al may end up losing more heat due to the large wall surface area and higher conductivity.
__________________

04-01-2013, 02:08 AM   #334
xtian116
Recipes

Oct 2011
Pomona, California
Posts: 279
Liked 63 Times on 40 Posts

I'm cheap, so I use aluminum pots that I get for tamales. A 52qt pot for \$30, you can't go wrong. I did notice, when I was oxidizing them, they actually retained the heat pretty well. It was in the high 40s over night outside, they were still over 120 degrees the next morning. (After about 7 hours)

04-17-2013, 04:08 PM   #335
Hall_Brewing
Recipes

Oct 2010
Mansfield, WA, Washington State
Posts: 11

passive oxide layer must be built up before brewing (**see note below) with a new aluminum kettle, although it is very easy to maintain

Where is the note that says how to do this?

04-17-2013, 06:50 PM   #336
xtian116
Recipes

Oct 2011
Pomona, California
Posts: 279
Liked 63 Times on 40 Posts

Quote:
 Originally Posted by Hall_Brewing passive oxide layer must be built up before brewing (**see note below) with a new aluminum kettle, although it is very easy to maintain Where is the note that says how to do this?
Just fill it up and boil water in it for at least an hour before you use it. Personally, I did 2 hours but kept topping it off as water evaporated.

04-19-2013, 01:38 PM   #337
CGVT
Senior Member

Recipes

Jun 2011
Spanish Fort, AL
Posts: 2,163
Liked 770 Times on 467 Posts

Quote:
 Originally Posted by xtian116 Just fill it up and boil water in it for at least an hour before you use it. Personally, I did 2 hours but kept topping it off as water evaporated.
Overkill, IMO.

Just take it out of the box and use it. It will be fine.
__________________
"Filled with mingled cream and amber I will drain that glass again. Such hilarious visions clamber through the chambers of my brain--Quaintest thoughts--queerest fancies come to life and fade away; Who cares how time advances? I am drinking ale today"-Edgar Alan Poe

My Keezer build: http://www.homebrewtalk.com/f51/keez...y-turn-340755/

Quote:
 Originally Posted by TyTanium Do what you like, brew what you like. Don't be a tool.

04-19-2013, 02:57 PM   #338
wilserbrewer
BIAB Expert Tailor

Recipes

May 2007
Jersey Shore, New Jersey
Posts: 9,599
Liked 1398 Times on 1070 Posts

Quote:
 Originally Posted by CGVT Overkill, IMO. Just take it out of the box and use it. It will be fine.
Yea I'm tempted to agree here as well...perhaps a little cleaning prior to use is warranted, but I agree that the level of concern for oxidizing aluminum pots is overstated...aluminum will oxidize plenty through use.

I've never read a post, "first batch ruined, didn't oxidize my kettle". Aluminum oxidizes to some extent in air almost instantly.

04-19-2013, 03:51 PM   #339
xtian116
Recipes

Oct 2011
Pomona, California
Posts: 279
Liked 63 Times on 40 Posts

Quote:
 Originally Posted by wilserbrewer Yea I'm tempted to agree here as well...perhaps a little cleaning prior to use is warranted, but I agree that the level of concern for oxidizing aluminum pots is overstated...aluminum will oxidize plenty through use. I've never read a post, "first batch ruined, didn't oxidize my kettle". Aluminum oxidizes to some extent in air almost instantly.
Your both probably right. When I first started I don't even think I cleaned that turkey fryer when I un-boxed it. Figured is was going to be boiled. When I got my bigger pots, I was a little overkill on them because I wanted them to look like the old ones. Maybe it was my brewing that got better and not the layer on the pot.

06-01-2013, 12:57 PM   #340
CraigHathcock
Recipes

May 2013
Posts: 1

Just ruined an aluminum kettle with oxy clean...... lesson learned read first! Correction read everything first....