I have a machined aluminum air cleaner(yes, it's billet) that I want to remove the shine on. What are some techniques that can be used? I'm thinking sandblasting, glassbeading or a chemical process to etch/oxidize. I'm wanting an appearance similar to old aluminum valve covers that have a darker oxidized look. Like most here, I don't like the billet look but some billet items might be used if they can be "disquised".
I seem to remember a mention of using oven cleaner to remove the anodizing (if it is). That would get it to bare alum.
Quite right . Oven cleaner has a lye type substance that will remove anodizing quite easily . Experiment first by leaving the stuff on for a short period , extending the time until you get the results you want .
might try glassbeading then a trip thru the dishwasher.... some drain cleaners will discolor polished stuff as well.....easyoff oven cleaner will discolor aluminum and remove the shine.....(that ones from experience....cover those big rig tanks when removing lettering ....and wear gloves...) brandon
Ive always used sraight amonia on brand new silver jewelry to make it age and go dark in the recesses and then polish it with a polish cloth to get back an aged shine....works great...should work well on alumium too...try a small spot and see........cheers, Bert
Oven cleaner has worked for me. Like has already been said, keep an eye on it as the longer you leave it on, the more it works.
I always use vinegar and water to etch aluminum before I paint it. It is cheap, and mild enough that you can take your time and get just the amount of etching you want. I use a tub of warm water just deep enough to cover the part, and about a cup of vinegar. If the wife isn't around the bath tub is perfect hehehe. The neat part is if you check on it every 15 or so minuets, you will be able to see just how much the finish has changed. It will look like nothing is happening for a while, but once it starts you will be able to see it. This vinegar method has always given me a very even finish like a part that has been sitting in the sun for years. The longer you leave it in the vinegar, the duller/older it will make the surface. I have used easy off, too, but it always seems to be splotchy. Some parts real dull, others still shine like they haven't been touched. Best part is vinegar is CHEAP! You probably already have it in the kitchen. -Dave
Use a scaler to make it look cast. http://www.use-enco.com/CGI/INSRIT?PMAKA=510-0687&PMPXNO=8901128&PARTPG=INLMK3
jj mack, I have seen those things for years, but never used one. Are they worth the money? What else do you use yours for? -Dave
Not much...... If you have a bead blaster the bead blaster works much better for removing paint, which is what I think these were made for. But is you have to repair cast aluminum you can make the weld "disappear" by using one of these.
There is a treatment called "Liver of Sulfer" that'll darken it down to black in seconds. It's used in jewelry work. Try it after a light sandblast and then lightly buff the high spots, should give you a nice cast look. Flatman
A scaler is for removing rust scale. Originaly and still mainly used in the marine world, any squid will know these!
Also before blasting the part you might want to try using a file, grider, or an agressive sand paper to knock off any sharp or crisp edges, that will help age it, and give it more of a cast look as well.
Thats mostly what I've used them for. Some air chisels will also take the needle attachment. Those things will pock mark heavy mild steel plate. I'd be a bit concerned myself using one on aluminium.
Try a blaster with aluminum oxide for the media. When you get it out of the blaster wash with water then hit with some indusrtial strength aluminum wheel cleaner. Rinse and repaet for the look you want.
This is a good tip! My wife makes jewelry and uses this stuff all the time. It doesn't take much and it works like magic. It will turn metal black if you leave it soak long enough. Brand new silver pieces look like antiques in a matter of minutes.