Thin rubber mat on the inside, vinyl wrap on the outside. Costs next to nothing.

I use the sticker-like shelf liner sheets that you get for kitchen shelves. Cheap and effective.

Or you can remove all the hardware leaving only the aluminum box, and take it to a professional. All my boxes are clear (in anodizers parlance that’s “white” but it’s clear to you and me) anodized, then painted white. Works great and 37 years later still no issues with blackening of gear. I even anodized some mounting brackets in clear and black. Nice, easy to do, and price seemed reasonable for the results. Anodizing also “surface hardens” and toughens the alloy.

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Grant Johnson
Seek, and ye shall find.
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Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com

Basically you are right and why I did anodizing years ago, here is what I remember about the process. And it´s also the reason why I would never do it again by myself with panniers. Surfaces are too big and the shape of them is too complicated for surface handling. For panniers the goal must be to reach a really thick anodized coating because otherwise thin anodzing films will be damaged outside by scratches/dust/sand and inside through rubbing of load easily.

Before you can start to anodize all metall area need to be clean, sanded and polished. Every kind of existing surface coating like paint or little scratches will ruin your results.

When you work with Sodium hydroxide and with Sulfuric acid you have to take safety measures. You will need a good ventilated room because during the process Oxyhydrogen will be produced which is higly inflammable and explosive.

After sanding and polishing you clean the metall surface with a mixture of destilled water and drain cleaner (Sodium hydroxide) which you normally use in your household. You can buy special and expensive products for metall surface cleaning and the advantage is that they keep the ph factor leveled. Which will influence the quality of the anodizing process. Also you use Sodium hydroxide to remove an anodization layer if you failed.

A destilled water bath will be needed after every process for cleaning the surface.

Sulfuric acid will be the fluid for anodizing, it´s nothing else than battery acid which always contains 37,5% of Sulfuric acid. For anodization a percentage of 15-20% is needed, so you have to mix it down with normal water. And of course you will need a colour for the coating.

Down in the anodizing bath you use lead which is comes from the roofing business and can be bought in roles. This will be your cathode.

For the anode best to use is a piece of titan in form of a stick. Also for fixating all metall piece you want to anodize you use titan wire. Why? Because all other metalls will react chemically or disolve in the process.

For controlling the temperature of the anodizing fluid, you can use an air pump from a fish tank with a perforated tube. Temperature in fluid must kept under 20°C, if temperature gets higher the anodizing process fails. You can also use thermal packs for this because as colder the bath is as better will be the anodization result.

You need a power supply which is stablized and used in laboratorys. Will cost you starting from 100€. You need a power supply at minimum of 200W++ and it must have the feature to hold a fixed amperage because the liquid resistance in the Sodium hydroxide will change during the process. If your power supply is not stabelized you have to measure resistance and correct the amperage constantly during the process. This is too complicated and a potential failure task.

The formular for calculating amperage is: for 100 square centimeters of metall you need 1,5A per hour. Now think about the inside and ouside surface of panniers to calculate power and size of your power supply! If your power supply is under powered you have to extend the time of process which makes it more complicated. You also need titan wire to supply electric energy and their quadrat diameter has to be in relation to the needed amperage.

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