Is my keg stainless steel or aluminum?

Have you ever wondered if your 15 gallon keg is stainless steel or aluminum (or aluminiumimum if you live across the pond) Well wonder no more! I have in my posession a stainless steel keg, and an aluminum keg for comparison. Behold!



The stainless steel one is on the left, the aluminum one is on the right. Notice the duller, more uniform color on the right hand one, and the left on has more varying shiny spots.



A closer look at the two kegs. You can see the color variation a lot more here. The one on the right is noticably lighter, but I don't have a scale to weigh them with. The fittings on top are identical. So there you have it!

Can I get a Sticky sticky?

Do a scratch test, too. And demonstrate the supposed "magnet test." Then you'll be my hero.

d'oh! I forgot all about those. I shall return...


OK back. Well, the pictures for the scratch test came out blurry, but they were identical anyways. I used a nail file and tried to gouge as deep a furrow as I could, but it barely scratched the surface of both. I was going to use a rasp on them as well, but the SS keg is so scratched up you couldn't tell where the rasping on it was anyways.

Here's the magnet tests. I used plain ol refrigerator magnets.

The aluminum test. For some reason it failed to adhere to it.



And now the stainless steel test.



Also didn't stick! It fell right off, just like the aluminum test.

So there's those! I suppose another way to tell if it's SS or AL is to boil hot water in it, and the dark oxide will form on an AL keg, but not in the SS keg.

You acquired those ethically I trust... I jest, I jest! What's in store for those guys anyway?

Yup my neighbor pulled out a stainless Firestone keg like you have on the left. It has been over grown in a ivy fence the last 8 years just discovered. It's the odd duck as all my kegs are AB, this odd Firestone will be my plasma practice cutting, sawing, milling apart, welding and practice on keg in the future. It just isn't right to have a single tier with two A Bush kegs then one Firestone in the lineup, just flat looks out of place.

EvilTOJ said:

The one on the right is noticably lighter, but I don't have a scale to weigh them with.

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Don't you have a bathroom scale? Did Plumpy break it?

No, I lost that in the divorce. Any other time I weigh myself is at the gym, so I've never had the need to buy one.

I'm fat. Anyways, I edited the post above to include my scratch test and magnetic testing. I'm not sure what I'm going to do with them exactly. I have three SS kegs, and this AL one. I'm thinking of making a fermenter out of one of them, and a 3 tier out of the rest some day.

so now we know that magnets only stick to ferrous metals like iron and cobalt and not to SS or Al. The easy test is weight.

I think you've got 2 SS kegs, bro. Aluminum kegs are very rare because they're just not sturdy enough to hold up to the abuse they take. I think the ones that are out there are typically imports.

The file/gouge test would've had very different results between the two, as aluminum is much softer than SS. You should've been able to easily file off or dig a big gouge in the aluminum.

Touch an angle grinder to it... there should be a pretty big difference.

You could have just done a magnet test. If it sticks it's SS.

OOPS...like my life...Day late dollar short. What Giligson said.

Magents Do Not Stick To SS Kegs!!! Unless all of my cornies and keggles are aluminum... I think there are like 10 threads on here alone about this issue LOL

The Pol said:

Magents Do Not Stick To SS Kegs!!! Unless all of my cornies and keggles are aluminum... I think there are like 10 threads on here alone about this issue LOL

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Lower grades of 300 series SS is magnetic without rust problems.
You need to tell my magnet to stop sticking to the Lind Brewing Company's 15.5, Jack Danials 15.5 (yes Jack made suds), A Bush 7.75 gallon kegs, 7.75 Full Sail and half of my 5 gallon Cornelius manufactured kegs that are all made of stainless steel. Not all stainless steel kegs can hold a magnet some will. This while leaving aluminum out of the picture completly. Same with some Cornelius by brand name 5 gallon Pepsi kegs, some are slightly magnetic some none at all. A correction was needed here boss just like Tig welding aluminum with stainless filler or stainless with aluminum filler is way off the common sense chart of any Tig welder or a person that works with different metals stainless included.

eschatz said:

ohhhhhh!!! ZING!!! :rockin:

magnets dont stick to my kegs damnit!

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Cuz they arent the cheap "powerman 300" SS that the chinese use to store tainted milk for thier babies

The Pol said:

Magents Do Not Stick To SS Kegs!!! Unless all of my cornies and keggles are aluminum... I think there are like 10 threads on here alone about this issue LOL

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Powerful magnets do stick to SS. Refrigerator magnets may not.



First picture shows a super magnet stuck to my keggle. I tried the same with some magnets I had on my refrigerator and I couldn't even feel it pull.


They are some pretty powerful magnets though, here is a picture of them holding together through my hand. No photoshop tricks here.

I also tried them on a number of corny kegs i had in the garage(both pepsi and coke) and I could feel a pull on all of them. The magnets couldn't quite hold them selves up because of their weight, but i could definitely feel them pulling. The magnets do stick to my 316SS ball valve as well.

The Pol said:

Magnets Do Not Stick To SS Kegs!!!

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Then tell this magnet to cease and desist immediately!



Actually, it's a REALLY strong magnet, and it only sticks to SOME of my STAINLESS cornies and 1/2 bbl kegs. The magnet test is not definitive. If the magnet sticks, your keg is surely stainless. If not, your keg still MAY be stainless.

Okay, fridge magnets will not stick and TIG welding high carbon alloy geraniums to low density fiber optic needle valves is not possible, that is common sense! I know, I stayed at a Holiday Inn Express last night.

Yuri_Rage said:

If not, your keg still MAY be stainless.

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Haha, damnit! I should have never stuck my nose into this thread. Now I don't know what my beer is laying around in!!!!!!!

eschatz said:

Haha, damnit! I should have never stuck my nose into this thread. Now I don't know what my beer is laying around in!!!!!!!

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Better than what most of US were layin with in college! LOL

Yuri_Rage said:

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The Old "West German Cornie Magnet" Trick huh..... I thought I'd been had.

BrewBeemer said:

Yup my neighbor pulled out a stainless Firestone keg like you have on the left. It has been over grown in a ivy fence the last 8 years just discovered. It's the odd duck as all my kegs are AB, this odd Firestone will be my plasma practice cutting, sawing, milling apart, welding and practice on keg in the future. It just isn't right to have a single tier with two A Bush kegs then one Firestone in the lineup, just flat looks out of place.

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I'd love to have it to get rid of my ab keg, wanna trade?

sanders5x said:

I'd love to have it to get rid of my ab keg, wanna trade?

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Check your PM.
Carl........

Lil' Sparky said:

I think you've got 2 SS kegs, bro. Aluminum kegs are very rare because they're just not sturdy enough to hold up to the abuse they take. I think the ones that are out there are typically imports.

The file/gouge test would've had very different results between the two, as aluminum is much softer than SS. You should've been able to easily file off or dig a big gouge in the aluminum.

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The aluminum keg is from a defunct cider brewery in the Portland area so I'm guessing they were custom jobs for that particular brewery. It is noticeably lighter than the SS keg and they're both empty. I figured the refrigerator magnet wouldn't stick at all, but I didn't want to order a neodymium super magnet kit just for you people

Just as an FYI, I tried scratching my AL turkey fryer pot when I got home from the storage unit, and apparently I'm a wuss because I couldn't scratch that at all either.

Many kegs I have seen will have the material imprinted somewhere on the kegs, a very easy way to tell stainless steel from aluminum.

giligson said:

so now we know that magnets only stick to ferrous metals like iron and cobalt and not to SS or Al. The easy test is weight.

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lol...


also the "scratch test" isn't definitive either... maleability of aluminum is dependant on the alloy - some aluminum alloys are extremely hard and scratch resistant -but usually at the cost of being prone to cracking or shattering when struck with a heavy blow.

the guy with the angle grinder idea is probably the best way to be 100% sure...

YAY!!! SPARKS!!!

Angle grinder, eh? Well it just so happens I bought an angle grinder not too long ago, I guess I can set up some sparkage in the morning.

Snuffalupagus said:

lol...


also the "scratch test" isn't definitive either... maleability of aluminum is dependant on the alloy - some aluminum alloys are extremely hard and scratch resistant -but usually at the cost of being prone to cracking or shattering when struck with a heavy blow.

the guy with the angle grinder idea is probably the best way to be 100% sure...

YAY!!! SPARKS!!!

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Y'all are making this way too hard. Simply strike the keg sharply with a BFH. If the resulting tone is A sharp, it's SS. C flat, it's AL. If you use a really BFH, the aluminum dents easier than SS.

Beers,
Ken

The scientist in me wants to say something...

If both kegs are negative for the magnet test, you have a null result for the scratch test, and you're not weighing them, then you have no reason to think that these kegs are even different material, let alone any indicator of which is which.

Both aluminum and SS can be shiny or dull. That's not really a fair indicator either.

A steel nail should scratch Al easily, but not SS. Hasn't anyone taken geology 101?

Thank god this one came back from the dead!

Ha! Sorry about that, I found this thread on google and I didn't realize how old it was before I posted.

EvilTOJ said:

Have you ever wondered if your 15 gallon keg is stainless steel or aluminum (or aluminiumimum if you live across the pond) Well wonder no more! I have in my posession a stainless steel keg, and an aluminum keg for comparison. Behold!

The stainless steel one is on the left, the aluminum one is on the right. Notice the duller, more uniform color on the right hand one, and the left on has more varying shiny spots.

A closer look at the two kegs. You can see the color variation a lot more here. The one on the right is noticably lighter, but I don't have a scale to weigh them with. The fittings on top are identical. So there you have it!

Click to expand...

I have 2 legs that appear different in composition but they both are as, the difference lies in the manufacture or manufacture date in some cases, the companies often have different suppliers of the kegs, and they also have different suppliers of the materials they use. so the look test is all that just a look, have you ever heard don't judge a book by its cover?
the grinder test should work, but a sure fire test is a acid test ,all doubts are gone with the results of it.
On the rim file a small spot and with eye dropper put a couple of drops of muriatic acid on it ,if its aluminum it will react to it if its ss ,it will do nothing.... have baking soda on hand to neutralize the acid. And wear proper protection and have adequate ventilation ( outside).. there are not many aluminum kegs out there but they do exist....

jcb317 said:

Powerful magnets do stick to SS. Refrigerator magnets may not.

First picture shows a super magnet stuck to my keggle. I tried the same with some magnets I had on my refrigerator and I couldn't even feel it pull.

They are some pretty powerful magnets though, here is a picture of them holding together through my hand. No photoshop tricks here.

I also tried them on a number of corny kegs i had in the garage(both pepsi and coke) and I could feel a pull on all of them. The magnets couldn't quite hold them selves up because of their weight, but i could definitely feel them pulling. The magnets do stick to my 316SS ball valve as well.

Click to expand...

high grade s.s. will not hold a mag

chs9 said:

The scientist in me wants to say something...

If both kegs are negative for the magnet test, you have a null result for the scratch test, and you're not weighing them, then you have no reason to think that these kegs are even different material, let alone any indicator of which is which.

Both aluminum and SS can be shiny or dull. That's not really a fair indicator either.

A steel nail should scratch Al easily, but not SS. Hasn't anyone taken geology 101?

Click to expand...

you mean metallurgy 101....
Geology is the study of rocks and the earth

jo jo said:

I have 2 legs that appear different in composition

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I feel for ya, man!
Must be a real ***** limping around like that.

Nice necropost too! 2010 was the last entry.

IslandLizard said:

I feel for ya, man!
Must be a real ***** limping around like that.

Nice necropost too! 2010 was the last entry.

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dang spell check,or my fingers are to big ,I should have reread before posting and better late then never, I didn't notice when it was posted ,today is my first day on homebrew talk, i,ll catch up later....

jo jo said:

dang spell check,or my fingers are to big ,I should have reread before posting and better late then never, I didn't notice when it was posted ,today is my first day on homebrew talk, i,ll catch up later....

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yeah I see the date now 2008 hah....

jo jo said:

dang spell check,or my fingers are to big ,I should have reread before posting and better late then never, I didn't notice when it was posted ,today is my first day on homebrew talk, i,ll catch up later....

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You can easily edit your own posts, click on the [Edit] button below any of them. There's a time limit on edits, though.

But that one was hard to pass up, sorry!

BTW, welcome to HBT!
Maybe find some more recent threads to participate in?