Simple Green Speaks Up

Simple Green has evaporated after nine days, leaving the foil with a green gel on it, but otherwise unaffected

In my previous post, I asked Simple Green what I needed to do to get Simple Green to actually EAT aluminum. They indicated that there was some etching with 5456 aluminum. I'm not familiar with that particular alloy, but in the Aerospace Industry, we commonly use other 5XXX alloys for aluminum honeycomb core. To summarize, I would NOT suggest soaking metal parts that have corrosion-susceptible alloys for weeks at a time in Simple Green. Use it, and then wipe/wash it away. It's what I do and I have NEVER had any problem with it. You are even LESS likely to have problems if the aluminum is painted, as on a frame. Anyway, here's the story FROM Simple Green - I sense some tenderness from them on this:

Steve A to Laura tonight:
Thank you. Your answer was very complete and helpful, and explains why I have never had any problems personally with your product, unlike with many others.

-Steve A

On Dec 7, 2009, at 7:08 PM, "Laura" wrote:

Dear Mr. Averill,

Thank you for contacting Simple Green and for your interest in Simple Green products.

Many years ago, Simple Green was submitted for Mil-Spec testing. One of the tests involved required soaking a bare piece of aluminum for 24 hours in a heated solution of 1:48 Simple Green to Water. Aluminum Alloy 5456 showed some etching and thus failed the test. Although there was no effect on some other Aluminum’s, our product was thus branded as an “aluminum eater”. I have attached a copy of this test for your records.

Simple Green will not “eat” Aluminum. It may, on certain alloys, cause indiscreet etching which may not be visible to the naked eye or at most be visible through slight discoloration.

Simple Green may present some risk if one chooses to completely immerse their Aluminum, of certain grade, in a solution for up to 24 hours. Applying and rinsing off within 5-15 minutes will not cause any sort of problems. If there is any cause for concern, you can switch to our Simple Green Pro HD solution, which has passed some Boeing and Pratt & Whitney specs allowing it to be a exterior surface wash, thus not causing any sort of problems for aluminum.

I hope you find this information useful. If you have further questions about this or other Simple Green products or uses, please feel free to contact me directly. My contact information is provided below and my regular business hours are Mon thru Fri from 8 – 5 Pacific Standard Time.

Thank you again for your inquiry.

Sincerely,
Laura
Environmental & Regulatory Coordinator
Sunshine Makers, Inc. / Simple Green
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My original query to Simple Green:
Your FAQ suggested that Simple Green might have problems with aluminum if not used according to instructions. About the same time, it was suggested to me that Simple Green would "eat" aluminum. As a result, being an engineer, I decided to do a test and left a piece of aluminum foil immersed in Simple Green to see what, if anything, would happen. Well over the course of the last two weeks, the Simple Green has evaporated and now is Simple Green gel. What do I have to do to get the Simple Green to eat the aluminum?

Personally I LOVE Simple Green, but I DO use it to clean a lot of aluminum parts and would like to better understand when it might present some risk. Clearly it isn't real agressive towards aluminum foil when undiluted and in a clean solution.
Name: Steve Averill


PS: There was also an attached pdf to the email that showed corrosion results, but for unknown reasons I can only see it on my iPhone and can't attach it to this post. For the 6XXX alloy tested (probably what bike frames are usually made of), there was no corrosion. Interestingly, though I did not ask, it appeared that Simple Green was more likely to corrode high strength steel than aluminum or other alloys, suggesting that it would NOT be a good idea to soak a bike chain in it for an extended period. I have never done this so cannot comment from first-hand experience. Apply and remove and you'll probably not have a problem with any metal. Also, while the email did not put the testing into context, it looks like it was done in conjunction with the US Navy in 1994 based on a handwritten note at the bottom of the pdf saying "from NAVSEA, 3/24/94."

FWIW, aluminum foil may be 11XX aluminum (almost pure aluminum with not much else), or 5052. 5052 was one of the alloys tested with Simple Green and experienced no corrosion. 5052 is also a common alloy for making honeycomb core. In addition to aluminum, it has a bit of magnesium and chromium in it.

Is the Simple Green question settled, Mythbusters?