TECh request...how to remove anodizing on aluminum???

I need to remove anodizing from some aluminum fuel fittings tomorrow. I don't have time to order anything special. Is there a home remedy that works?

I've tried oven cleaner and it didn't work. Let the parts sit in it overnight and nothing. Any help is much appreciated.

Matt

 

Try drain cleaner, but don't leave overnight.

 

Oven cleaner.

 

Knuckledragger technique: Wire wheel, sandpaper, Scrotchbrite. Takes 5 minutes, works for me.

 

Oven cleaner. Dont use the odor free stuff. Get the stinky stuff, put fittings in a ziploc bag, spray in oven cleaner and set the bag in the sunlight.

 

I can play this game, too. Try toilet bowl cleaner.

 

I was told Red Devil lye.....

 

Ditto----


-----Stripping or restoring existing anodized parts-----
You can strip off the existing anodized layer from any anodized part by placing the part in a caustic solution for an hour or so. Just mix a few tablespoons of lye and water in a plastic container. Wear eye protection and rubber gloves for this procedure!! Place the part in the solution and monitor its progress.

The Lye will dissolve the old anodized layer, about .001" thick. It takes a while for it to start breaking through the layer. It's a little slow at first. The first ten minutes or so not much action will be seen. Bubbles and smut will rise up as an indicator of its progress.
It is a good idea to help the process along by wiping the smut off the part to allow the acid to get to fresh aluminum. Just wipe off the part with a rag every 5-10 minutes until the old layer is completely gone (wear gloves and goggles). Only bare aluminum should be seen when the part is finished. If the aluminum part turns a dark color then it needs to be desmutted due to its alloy type. For example, 2024 aluminum alloy has 5% copper in it. The lye eats the aluminum off the surface but leaves the copper behind which in turn tarnishes to a dark color. Desmut is the opposite of a caustic solution such as lye. Desmut (normally ferric acid based) eats the non aluminum metals off the surface presenting a purer aluminum surface to be anodized. I include desmut in the advanced anodizing kit for folks doing unknown or non typical 6000 series alloys. It could come in handy and does not hurt to use it on all aluminum alloys.

http://www.focuser.com/atm/anodize/anodize.html

 

Caustic soda.

Very cheap, buy it in crystals, mix with water and imerse the parts. It'll fiz and get hot, takes seconds

(edit) Oh, already said above.

 

So this is where my early 80's "metallic gold aluminum ain't cool anymore" BMX knowledge comes into play. Oven cleaner works great! Haven't tried the toilet bowl cleaner, but diet coke and aluminum foil seems to work for everything else! Don't forget to reverse the polarity when you apply the voltage!

 

Swimming pool acid. Just a minute is all it takes. Don't leave any open containers of this stuff around...it causes bare metal to rust...fast! Go outside, take the garden hose with you. Put a small amount in a spray can lid, dip the fitting in for a minute. Rinse well with water. Safety glasses and gloves are a good idea here. Be careful.

Craig

 

Basic Plain old Easy Off is all I have ever used. Works great.

 

I use Metal Prep (phosphoric) acid. Leave it submerged for a few minutes. It works great, Pool acid, (muratic acid) or caustic soda will hurt the aluminum if you leave it too long.
-TT

 

Thanks for the suggestions guys!!! I'll let you know what I used and how it worked

Matt

 

I tried the easy off method and it did not remove all of the anodizing. I still had to wire wheel my fittings (Earls).

 

Or you could have bought the fittings that aren't anodized.

 

Bringing old thread back up.....

I want to remove anodizing from some Wilwood caliper brackets, but the aluminum brackets have 4 steel inserts where mounting bolts hold the bracket to another anodized bracket that holds the parking brake caliper. Do the caustic products recommended to remove anodization cause a problem for the steel inserts? Or only touch the aluminum?

 

I use “Lime Away” to remove zinc plating, it works in seconds. It may work on the anodizing also. Steal some from the little ladies cleaning cupboard and try it.

 

Anodizing is typically less then a half thousands of an inch thick unless it is hard anodized for wear which can be a few thousands of an inch thick. Most anodize is done for cosmetic reason and some protection from corrosion. Hard anodize is done for wear resistance and corrosion protection. I would think the bracket you have was done for cosmetic purposes.

If it were me I would just sand the anodized surfaces with paper down to the base metal and then go over it with scotch-brite or use a wire brush in a drill motor then follow with scotch-brite. Some oven cleaners and other chemicals can actually pit the aluminum surface. My opinion your mileage may vary. You didn’t say if you were going to recoat with paint but if you remove anodize bare aluminum corrodes very quickly.

 

Probably going to clear the part once it is bare aluminum. Unless anyone has a better suggestion on keeping it looking relatively decent over time. Gibbs maybe? Not after maintaining a show polish look at all.

 

I helped prepare some aluminum parts for anodizing once on a new build IMSA GTO car way back when, and after wet sanding everything with fine paper we used some sort of an acid wash to really get them clean. I don't recall what the acid was or the dilution rate, but it was pretty strong stuff, smelled foul and caused the aluminum to foam in a fine mist of bubbles after just a few seconds. Water was used to neutralize it quickly and the parts turned a bright silver-white color. Gloves and mask recommended. Then the parts were shipped out for anodizing. I bet a call to a place like that could give you some tips. None of the parts we had were previously anodized, sorry to say. But that acid seemed like it could dissolve anything if left to work long enough. Many of the race car's parts were plated or anodized after the car was blown apart for final paint, etc.. Come first race in the spring, she was a beaut.

 

That would be nice!

 

This was a red line end and a blue elbow, all I could find one night at the poorly stocked speed shop in Portland. I threw then in the glass blaster, polished them on the wheel, a dip in the parts washer, another trip across the wheel and installed. They look as good today as they did 3 years ago with no maintenance.