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!

http://www.homebrewtalk.com/gallery/...m/SS_vs_AL.jpg

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.

http://www.homebrewtalk.com/gallery/...SS_vs_AL_2.jpg

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.

http://www.homebrewtalk.com/gallery/...et_test_AL.jpg

And now the stainless steel test.

http://www.homebrewtalk.com/gallery/...et_test_SS.jpg

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... :D 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.

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.