Removing oxidation from an aluminum mast…?

[paularey]

Just getting ready to clean up my bare aluminum mast and I was looking for any suggestion on what over the counter (in Central America) product might work best. I would like to give it an acid bath of some kind followed up by a light polishing and waxing. I have had many suggestions from Drano to Vinegar given to me but I’m open to more suggestions if they have a practical application. Much thanks in advance for any input.

[haworth1967]

When I first found my aluminum boat it had 50 years of oxidization, and looked pretty dull. I used an old truck drivers trick for polishing aluminum wheels. You can buy an assortment of small canvas buffing wheels that fit an electric drill at most home improvement stores as well as some "Jewelers Rouge" that comes in a stick form. With a little time and effort (vastly superior to hand rubbing) my aluminum boat shines almost like chrome! Good luck! Hope this helps!
Mike

[Willallison]

Don't touch it!
When aluminium oxidises it forms its own 'protective surface layer'. Removing that layer will only cause the Al to start the process over again. Do it enough, and you wont have a mast left.
The only way to circumvent the process is to apply a permanent non-permeable protective layer - such as paint. Wax will probably work for a short period, but unless you plan on scaling the mast to redo it every couple of months then you would be wasting your time

[Frosty]

Will is absalutely right, However if you insist--- wet and dry 400 with lots of soapy water will brighten it up a bit. You and the sorounding area will be blackened from the water. You will look like you have been attacked by a giant squid. Why it does that I dont know!!

[MikeJohns]

Was it anodised to start with? If not they are usually painted.
Caustic soda cleans up the surface to a bright finish but it will dull again with salt air in short order. Painting with a roller and a matt air dry epoxy seems to be a good solution here.

Cheers

[paularey]

Thanks everyone I appreciate the input and concern. I’m not totally in the dark here I know quite a bit about the properties of aluminum and oxidation, protective barriers, anodizing, aloding, painting etc, but that’s not really what I was searching for info on. I realize bare aluminum oxidizes but my boat is 25 plus years old with a bare aluminum mast with a moderate even accumulation of surface corrosion which makes it dull and unattractive. I don’t think in my life time it will ever disappear if I take it back to a bare surface and start the oxidation process over again. I realize it will eventually get dull again and that’s ok. I don’t really want to spend the considerable effort required to paint it correctly, that involves a lot of work and I’m not looking to buff the whole mast with a buffing wheel. What I was hoping for was someone’s practical experience with an over the counter products that attacks oxidation not aluminum. Sodium hydroxide is a good one and yes I realize it removes anodized surfaces but my mast if it ever had it has long since lost that property. I usually get the same story from people, they say this “I used this stuff once along time back it worked great I just brushed it on and it foamed up and I washed it off to a bright clean surface” Only problem is they can never remember what it was..? Any help finding something such as this that I have heard people speak of is much appreciated. Thanks again.

[marshmat]

3M has a 'marine aluminum restorer' polish that we use on the suspension bits of the solar car. Never tried it on a mast, but it does a decent job with the oxide that builds up on uncoated aluminum. Granted, our parts are a foot long at most, and I'm not sure if you want to do that much rubbing and polishing on a big mast.

[Willallison]

Originally Posted by MikeJohns

Was it anodised to start with? If not they are usually painted.
Caustic soda cleans up the surface to a bright finish but it will dull again with salt air in short order. Painting with a roller and a matt air dry epoxy seems to be a good solution here.

Cheers

Mike - are you kidding....?
Aluminium dissolves in sodium hydroxide (caustic soda)!

[paularey]

• Thanks for the input, your both correct, Sodium hydroxide, also known as lye or caustic soda cleans up aluminum great and yes it does dissolve it but that would be tough for me to accomplish notably with it still attached and standing on my boat! I would have to immerse it in a strong solution for a significant period of time to dissolve it enough to effect its integrity. Even unprotected aluminum resists corrosion because it builds a strong thin layer of aluminum oxide on its surface. This layer can be strengthened further by anodizing the aluminum. It’s difficult to tell if my mast was ever anodized..? I believe it may have just had a funky clear coat applied that has long since vanished. It has an even layer of oxidation on it now. I just want to brighten it up and start the process again. I’ll probable try cleaning it up with EasyOff, which has a low level of Sodium hydroxide as the active ingredient and it is relatively easy to apply since the mast is standing. I’ll probable just wax it occasionally after that. It would be a pain to paint because it has small stainless step/rungs the full length of the mast and masking them off or painting them would be quite the task that I’m not up to undertaking. I’ll keep you posted on the results..?

[catmando2]

What we have used in Australia as an acid wash was a product call Allbright Heavy. It is a phosphoric acid based product. Froths white foam , wash off with water and put your sunglasses on.

Then we coat with a Valvoline product called Tectyl. I think the alluminium version is Tectyl151. We just wipe it on with a rag and give the mast several coats. This stuff lasts for years and is easily touched up with another wipe with the rag. It dries clear.

Hope this helps.

Dave

[Willallison]

If you really want to clean aluminium up, the best thing to use is chromic acid. It removes the bulk of the white oxidisation 'crust', then re-oxidises the surface, giving it its protection back
BUT - it's not for the inexperienced. I'd strongly recomend going with a proprietry product - like those suggested by others.

BTW - if you dip your mast in a concentrated sodium hydroxide bath for a significant period of time, as you suggest, I'll GUARANTEE that it wont be there when you come back to get it. I deal on a daily basis with NaOH ranging from very dilute (0.03 N) to to strong (50%) to solid (ie 100%). It's nasty stuff - not toxic or poisonous as many will suggest, but certainly corrosive. Get it in your eyes and you will start to have permanent damage within 30 seconds. More than a minute or two and you'll never see again.

[PAR]

Penetrol (an oil based conditioner for alkyd paints) will remove the oxidization (with elbow grease and ScotchBrite pad if necessary), though as mentioned, the oxidation is aluminum's natural protective coating. Rub on, scrub as needed, then buff off. The remaining residue can be left in place to offer some protection (or removed), though it will not last as long as paint or other commonly employed aluminum finishes. On heavily oxidized material, you'll have a fair amount of scrubbing to do with most products, including Penetrol. The benefit of Penetrol is it's non-abrasive, restores luster, offers some protection, low cost, ease and safety in use, compaired to some other products.