Ok so now you’ve committed yourself to de-anodizing your Silver Streak trailer, or anything else large and made of aluminum with anodization on it; you have a few choices now in terms of chemicals to do the job. I chose Sodium Hydroxide, which in my experience is the best at doing this without damaging the metal, but there are others, however many are not included in household products like Sodium Hydroxide is making them a lot harder and more expensive to buy. A good article here on removing anodized aluminum and the benefits of various chemicals:
https://aerospacemetalsllc.com/how-t...ized-aluminum/
Disclaimer:
A word about Sodium Hydroxide and chemistry, it is a Base (vs. an Acid), essentially a really strong Lye (as an example sodium hydroxide is often used in the making of homemade soap or drain cleaner because it helps dissolve organic oils) and like all bases it is caustic, REALLY caustic in our application given its concentration percentage.
“Caustic: adjective meaning able to burn or corrode organic tissue by chemical action.” aka:
**BE CAREFUL, WEAR PROTECTIVE CLOTHING, A RESPIRATOR (like the ones used when painting a car) and FULL FACE PROTECTION. I can not stress this enough. I made the mistake of not wearing a full face mask and had my spray bottle accidentally on stream vs. spray and had a ricochet shot of burning liquid onto my forehead.. please be careful.
Where do I buy it and what is it in?
So the best place I found to get Sodium Hydroxide in a common household liquid was The Home Depot. I am sure there are other brands or kinds of cleaner/liquid which include Sodium Hydroxide in high concentrations but this one was the highest I was able to find at a reasonably low price. BTW if you are curious about how to figure out how much Sodium Hydroxide a given product has, Home Depot makes it easy, just click on the “SDS” link under Specifications and look for its chemical composition. Note this is never listed on the actual bottles themselves, you’ll be lucky to even see Sodium Hydroxide listed; this info is considered a trade secret by the vendors but they all have to list it in their Material Safety Data Sheets which can be found on their websites or in this case, Home Depot’s.
Easy Off is only 1-5%
Instant Power Hair and Grease Drain Cleaner is 29-50%
At only $11.00 for a gallon I am using a product called “Instant Power Hair and Grease Drain Cleaner” SKU #417841. It contained Sodium Hydroxide in a concentration of between 29%-50% vs. Easy Off which only has between 1%-5%, this makes a huge difference in terms of how long it takes to remove the anodization and how long you have to leave the chemical on the metal. You will need about 5gal +/- to finish an entire trailer. Don’t use Easy Off! Despite its name it is neither Easy, nor does it get the anodization OFF (easily..)
Buy this:
You’ll need several generic high quality plastic spray bottles such as the Zep Professional also found at Home Depot. I found they only lasted a few hours before getting clogged up with the sodium hydroxide residue and I went through 5 of them.
To get the drain cleaner to stick to the metal (stay on a sufficient amount of time to de-anodize the material) you’ll need to add a little dish soap. This acts as a ‘Surfactant’ a fancy way of saying it makes it bubble or reduces the surface tension of a liquid. This is one advantage Easy Off has over using Drain Cleaner (Easy Off ‘sticks’ to the surface with lots and lots of bubbles) but due to its low percentage of Sodium Hydroxide its still not as good as drain cleaner…
De-anodization method:
1) Wash the trailer down with soap and water, wait for it to dry…
2) Take off all of your plastic lenses, license plate, spare tire, and anything else you want to prevent having its anodization removed, or its paint, or plastic melted in this process. Also cover the windows, the drain cleaner doesn’t damage them but it does make them a mess and Windex has a tough time taking off the anodization residue.
Important note: I tried to save the really cool golden anodized strip around the trailer, a unique signature of Silver Streak travel trailers and RVs; however it was a loosing proposition. No matter what I did to tape it off the Sodium Hydroxide got through it. My advice; paint the strip later gold (or another color, I’ve seen some blue ones that look pretty cool) or leave it polished it looks cool! -- preventing that anodization from coming off is nearly impossible and it makes the job way harder when you have to be careful where you spray.
3) COVER YOUR BODY, FACE, HANDS (thick rubber gloves used for caustic liquids), EYES, MOUTH (lungs) before you even open the drain cleaner bottle. I found the ‘bunny suit’ you wear for painting a car and respirator works great.
4) Pour the drain cleaner into the small spray bottles and drop a couple drops of dawn soap into the bottle, shake it up until you see small bubbles.
5) Divide the trailer up into quadrants I did 6 areas on my trailer, FRONT (R/L), SIDE (R/L), REAR and the ROOF. Start from the TOP (roof) and work your way down. Otherwise the anodization residue will drip down on the already de-anodized areas making double work.
Spray (on spray, not stream) small sections of the trailer with sufficient liquid to give it a good coat, don’t be afraid to use it judiciously.
The drain cleaner/soap spray needs to spend anywhere between 15min to 30min in contact with the material to start to remove the anodization. You’ll know its working when you start to hear it make a bubbling/hissing sound and start to make a purple looking liquid on the surface, about 5mins after application. DO NOT LET THE DRAIN CLEANER DRY – you must wash off the drain cleaner once the de-anodization has completed or you’ll need to de-anodize again (it sort of reapplies itself otherwise).
Note I found that I needed to do a little scrubbing with a soft brush to get some of the tougher areas de-anodized. Worse case you may need to do a couple applications.
6) Rinse the de-anodized area off with water until you don’t see anymore purple looking liquid.
7) In my method I don’t polish the trailer until the entire trailer is de-anodized. I saw other forum posts where the person did the de-anodizing, then polishing per section. I don’t think this is a good idea as you have to be super careful not to get the drain cleaner on those polished areas and increases the time it takes to do the job. De-anodize whole trailer, then polish!
8) When all the anodization is off, the trailer will look similar to what it did when it was anodized but more powdery. Don’t worry about this the anodization is either completely off or 99% off.
9) Polish as you would any Airstream aluminum trailer using your favorite products (plenty of videos on how to do this online) – we used the clay method and an orbital polisher. When you are polishing or having the shop do it, there may be small sections where anodization remains, don’t fret! If its a small area its very easy to fix yourself by applying the drain cleaner/soap liquid and polish again using a small orbital polisher or even by hand with a rag I found to work.. if it’s a larger area you can also reapply the drain cleaner and polish it again being really careful not to drip on your already polished areas.
And the finished product:
I also polished the aluminum/anodized window cover in the front of the trailer (which should be removed to do this) as well as the aluminum propane tanks which were already bare aluminum.
I am debating now whether or not to paint the gold stripe around the trailer again or leave if polished; I think it looks really cool either way.
Nothing beats the look of a mirror polished old aluminum trailer!
Post with any questions or comments, curious who else out there has a Silver Streak they are planning to de-anodize, happy to help anyone out there who wants to take this on!
shaun
the saga of de-anodizing a 1964 Silver Streak
My A.S. also lives outside in north eastern WA (12" - 16" annual precipitation.) 
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