Pitted Aluminum - How Screwed Am I?

Preparing for my first all grain batch, I borrowed an aluminum turkey fryer kettle from my dad. Because it had actually been used to fry turkeys, it was in line for a good cleaning. I thought running it through the dishwasher would be a harmless first step. Apparently not. After the wash cycle, I found several spots on the exterior bottom of the pot (where the dishwasher couldn't reach) where dried detergent was caked atop pitted aluminum. I suppose the cause and effect could have gone either way here - either the detergent caused the pitting, or else the pits collected the detergent, but I don't remember the damage being there before.

So, two questions:

1) Is it plausible/likely that the detergent caused the pitting?

2) Is the pot still safe to use? The pits aren't that deep and the pot still feels solid, but the damage is right on the bottom where it's gonna be hottest.

Thanks,
Jay

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Bigger version

Jay

Take a scotchbrite pad and scrub the inside very well till it is shiny, then fill it up with water and boil for about 30 mins to oxidize the surface and you should be fine. The beer won't be on the outside, so there is no real reason to worry about that!

Thanks. I did the boil and everything seemed to go fine. Gave me a chance to test my immersion chiller too - it took ~8 gal from 200F to 80F in 15 minutes (well, the thermometer read 80, but it felt cooler). Unfortunately, I'm not going to get to brew today (the Lost finale has claimed my evening) but I should be ready to go tomorrow.

Thanks again.

Jay

Unless you are afraid of springing a leak through one of the pits, I wouldn't worry about it.

The pits were likely caused by the detergent. Chemicals such as sodium hydroxide will pit aluminum. Sodium hydroxide (NaOH) is a caustic chemical and is typically reacted with a fatty acid to form a soap which gives the detergent some of its cleaning properties. Most dish washing detergents have an alkaline pH. This means there is still some unreacted sodium hydroxide or similar type of caustic left behind to pit the aluminum. Just use the scotch brite pad and be careful how you wash the pot in the future.

To avoid this problem in the future maybe you should consider a stainless steel brew pot. Stainless steel is much stronger then aluminum. Also I never wash any of my brew gear in the dish washer. Go to your local brew shop and talk to them, Im sure they will set you up.