Ch. 5 - Landing Gear mounts - Part 7

Alodine, the alchemist’s dream!  (2.0 hrs)

Alchemy was the medieval forerunner of chemistry, based on the supposed transformation of matter, and was obsessed with attempting to convert base metals into gold.

Alodine would have seemed like a magical potion to an alchemy practitioner, as anything it touches literally turns to gold, or more precisely, gold color. 

But let me start at the beginning, and explain what I am trying to accomplish.

The landing gear mounts will be located in what is usually referred to as the "hell hole”, basically a place very hard to reach, and to inspect. The necessity to ensure that corrosion does not affect this critical component, dictates that every possible precaution be taken. Alodine is an excellent corrosion inhibitor for aluminum, with the curious gold color side effect.

Alodine and aluminum prep

There are different brands of Alodine, and the one I chose is made by DuPont. This is some NASTY stuff, and most of the labels are covered in health warnings, so a well ventilated area, and thick chemical gloves are a must. 


Fortunately the chemicals are reusable, so they can be put back in the original container when done, so you don't have to worry about disposing of them until they lose their effectiveness.

Pretty simple setup

Alodining is a two step process. 

First, an aluminum part is dipped into an etching solution for a couple of minutes to prepare the surface...

Aluminum bubbling up

... then it is rinsed in water, and dunked into an Alodine vat for a couple more minutes, in order to transfer the solution onto the metal...

Alchemy at work!

...later the part comes out a beautiful gold color...

... and is rinsed once again...

... and left to air dry...

The result is pretty stunning, and the parts are now “operational”.

In case you were wondering, Alodine does not work on steel, as you can see in the next picture of my scrap test piece, where the steel bushings are still unaffected.