Rejuvenating a faded anodized finish?
- Thread starter mrclunk
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Gene Pink
Well-known member
Yes, but matching colors may be tricky. You might consider being happy with what you got.mrclunk said:
Soaking the aluminum in a moderately weak lye solution will remove the old anodizing and color dye. Then you will have a bare aluminum plate, and any screen-printed graphics will also be gone. And any steel you forgot to remove (pressed in nut threads?) will also corrode.
And if you really want to redo it DIY:
1) do the above.
2) make an electrolytic cell out of a plastic container much larger than the part, lined with lead sheet, connected to the (-) of a hefty power supply in the 16-20V range.
3) immerse the aluminum part in this cell, filled with a weak 10% sulfuric acid solution, ~1.100 SG, about dead car battery level will do, it just need to conduct, not be a strong acid.
4) somehow connect an aluminum wire or rod to the work that can handle some real current, and put about 1A per 2.5 square inches of the work area, into it, work is (+), as it is "anode"-izing. Maintain H2S04 solution at 45-50 degrees F, temperature is critical to the grain size that grows, and the current makes a lot of heat, keep adding ice. The current isn't critical, it will drop off when it is complete, lower current just takes longer.
5) Remove part from cell, rinse with distilled water, and drop into 130F dye tank. Last time I did this, the dye tank was a 5-gallon pail with Rit (brand) clothes dye in the hot tap water, scarlet red. Wait a half hour, and slosh it around a bunch. Once all the dye has soaked into the pores, they need to be sealed.
6) Throw part into boiling water for a good half-hour to swell all the tiny anodized pedistle grains together, to lock in the dye nice and permanent.
7) deal with the wife bi*ching about why her favorite largest soup pot has a red tinge that didn't wash out.
That's what's involved in DIY anodizing. If you don't plan to do this, you can buddy up with a local anodizing shop that is doing that particular color, and throw yours in too, if you don't mind waiting until they run a batch of the same color. Their minimum orders can get pricey, but they are pretty good about matching colors.
Gene
That is not a sign of age. Anodized hues don't fade. That is just due to the fact that it is impossible to guarantee hue consistency between different runs.mrclunk said:Is there an equivalent of "Back to Black" bumper polish for anodized aluminum
Bought another Focusrite Red 1 and its much lighter in colour that the others..
The only commitment you can expect from an anodizing service is heavy black or colorless.
They can, but they must be sanded or brushed back to raw metal; and that would not guarantee the same hue as the others, unless you de-do them all.
Matt Nolan
Well-known member
I may be wrong but that looks to me like the massive difference between the brushed finish of the faceplate and the not brushed finish of the rack bolts recess.mrclunk said:
mattamatta
Well-known member
I've definitely seen the dyes in anodized finishes fade from UV exposure from sunlight. Red turned to pink and black turned to a funny.... not black of some sort.
Gene Pink
Well-known member
mattamatta said:
Dye will eventually fade with exposure to light. That dye has faded.
I zoomed in on the above jpeg to the screw recess, obvious fading shadow around the screw washer. And that looks exactly like the same shade mentioned in my post above, Rit(brand) Scarlet Red.
I don't think there is much you can do about the fading, other than expose the other three to an intense UV germicidal fluorescent tube for a month, and fade them to match. Please don't do that.
Yeah, I know that "not black", sort of a silverish black that is not quite grey. ;-)
Gene
PS: Looking at that jpeg, note to all, when buying black nylon trim washers for #10 rack mount flat or oval head screws, don't get #10, get #8. They push onto a #10 screw just fine, and are less than 1/2" in diameter, they don't overlap onto the next unit.
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mattamatta
Well-known member
Gene Pink said:
I think the one I'm thinking of had a bit of a cool kind of grey with a golden brown luster. Actually looked pretty sweet. THis in particular was a part of a bike headset that was on the window-facing side of wherever it was I was storing it. Of course, this was before it was stolen
Gene Pink
Well-known member
Hmmm, a sort of bronze-grey? Interesting. Anodizing shops do a lot of bronze, commercial entrance door frames, stair railings... they hate black as it is hard to get it dark enough for the customer expectations.mattamatta said:Gene Pink said:
I think the one I'm thinking of had a bit of a cool kind of grey with a golden brown luster. Actually looked pretty sweet. THis in particular was a part of a bike headset that was on the window-facing side of wherever it was I was storing it. Of course, this was before it was stolen
Digging through old pictures and zooming way in, here is what stained my wife's soup pot. Made four of these breakout boxes out of 5"X2" channel extrusion, 3/16" thick. Eight pieces total.
