"Faded" Anodized Hitachi Front Panel

[Phase700b]

Hello. I just acquired a nice 3 piece matched set of a Hitachi FT-440, HCA-7500, and HMA-7500.

The front panels on the tuner and Control Pre-amp look fine, however, the HMA-7500 Power Amp has a faded, purple like appearance with copper undertones. It appears it may have been a poor finish when new since th inside is like this also. I'm looking for suggestions on how to refinish it and still retain the lettering and logos if possible. There is a craft product called "Swellegant" that has poly metal dye and sealant products. Any suggestions?

Here's some pics of the "nice" pieces after some general cleanup and of the poor anodized finish.

 

[tommy6206]

I cant help with the faded panel but I have the same pre-amp and like it alot..

 

[EchoWars]

Crappy anodizing job to begin with apparently. Options: clean it up as best you can and live with it, or have it re-anodized and re-silkscreened to put the lettering back on. This latter option will not be inexpensive.

 

[Phase700b]

I suspected the anodizing process was cut short or had problems during the dye process stage. But it almost seems like the panel is faded by light or exposure to something since there are shadow like areas around the small plastic logo in the lower right of the panel and around the meter bezels. Yes, having it redone and silk screened would not be cheap.

The amplifier works fine, so I may try masking off the existing lettering and using the metal dye craft product called Swellegant.

 

[R-2-R]

Swellegant?

I suspected the anodizing process was cut short or had problems during the dye process stage. But it almost seems like the panel is faded by light or exposure to something since there are shadow like areas around the small plastic logo in the lower right of the panel and around the meter bezels. Yes, having it redone and silk screened would not be cheap.

The amplifier works fine, so I may try masking off the existing lettering and using the metal dye craft product called Swellegant.

Please post pictures of the amplifier 'after' you have used the "Swellegant" product. I've never heard of it before but I am curious as to the end results.

I also have an old Toshiba system (tuner, pre-amp. & power amplifier) and the power amplifier has the same problem as yours. I take, it could be a combination of a number of things. One, being the original dye process, could be that for whatever reason that particular part/section just did not take as it should have? Two, add in using harsh cleaning products on the face of the unit just added to it's deterioration process. Three, the elements of exposure? As you stated, probably direct sunlite along with temperature changes, humity, etc.?

 

[Phase700b]

Please post pictures of the amplifier 'after' you have used the "Swellegant" product. I've never heard of it before but I am curious as to the end results.

I also have an old Toshiba system (tuner, pre-amp. & power amplifier) and the power amplifier has the same problem as yours. I take, it could be a combination of a number of things. One, being the original dye process, could be that for whatever reason that particular part/section just did not take as it should have? Two, add in using harsh cleaning products on the face of the unit just added to it's deterioration process. Three, the elements of exposure? As you stated, probably direct sunlite along with temperature changes, humity, etc.?

I agree, it could be a combination of issues. The thing is, the back side of the panel has the same appearance, although darker. It looks like an uneven and thin dye with some areas showing the copper/gold like color under the black dye. I think the copper/gold is actually what was used as a first color to provide the lettering. In looking at it closer, I can see that the lettering is not silk screened, but actually the copper/gold color substrate that was somehow masked off before the black dye process was done. Perhaps some contamination occurred during the process? And, yes, exposure to cleaning agentss etc probably made it worse. It almost looks like the front panel was wiped with something around the center area at one time.

I am trying to find a local supplier of the Swellegant products, but I live in a small area so may have to order it online. The closest color they have is called charcoal black and multiple layers can be applied. What sounds nice about it is that is gives a flat finish with no gloss including the final top sealer. You can look it up online. They have a website and also there are some craft videos on YouTube about its use.

When I find it, I will experiment on the back side of the panel first, and see how it goes and certainly post my results.

 

[tomlinmgt]

The dye used in anodozing is notoriously unstable to UV exposure and that's going to be the cause in just about every case of fading. I'm skeptical about the Swellegant product. That's primarily marketed to the arts and crafts industry to create interesting patinas so that means they are likely not concerned with a uniform finish. However, something may be better than nothing and I suppose it's worth a try but I absolutely wouldn't expect it to restore the anodizing to its original appearance. I'm in the metal surface treatment industry and I've not seen or heard of a product that will restore the dye in anodizing after it has lost pigment. Once it's gone, it's gone.

- Michael

 

[ConradH]

Michael is spot on. The dyes bleach in sunlight and there's nothing you can do about it. Hint to others- don't let direct sun or CFLs hit your black anodized components! The only fix is a strip and re-anodize job, and IMO you'll never duplicate the original look. Another possibility is a very high quality paint job and silkscreening or decals. Given how bad it is, that would be my approach.

 

[Phase700b]

The dye used in anodozing is notoriously unstable to UV exposure and that's going to be the cause in just about every case of fading. I'm skeptical about the Swellegant product. That's primarily marketed to the arts and crafts industry to create interesting patinas so that means they are likely not concerned with a uniform finish. However, something may be better than nothing and I suppose it's worth a try but I absolutely wouldn't expect it to restore the anodizing to its original appearance. I'm in the metal surface treatment industry and I've not seen or heard of a product that will restore the dye in anodizing after it has lost pigment. Once it's gone, it's gone.

- Michael

Ahh, Thanks for that bit of info! I wondered if UV could affect anodized aluminum finish. That would explain the slight shadowing I see on the face plate of the Control Pre-amp I also bought as part of the three piece system. The Tuner looks very good and very black, the Pre-amp is slightly faded and when I pulled the knobs off I can see "shadows" of where the knobs were. I suspect the tree pieces were stored on a garage shelf with a window nearby. But the Tuner must have been either in another location or covered up, ergo, no fading. All pieces were VERY dusty and even had cobwebs. . . like an old garage might have. I wish they hadn't done that.

I realize whatever I use that it won't ever look like the original finish. But I'll try a few things that may help it look better. I read where paints won;t adhere to anodized surfaces very well and will chip or flake after awhile. Any truth to that? There is another process for small batches of metal parts used by some makers of aluminum parts, but still too costly for me to consider.

My other thought is to wait and see if I can come across a parted out unit at some point. In the meantime, I'll try the Swellegant products since they are pretty inexpensive. If the amplifier wasn't still working I wouldn't bother.

It's a good thing I never allowed my other black anodized equipment sit out in sunlight or under CCFL light. Something to be mindful of in the future.

Thanks for everyone's input on this.

 

[EchoWars]

Here's a couple of repainted Kenwood units: http://www.audiokarma.org/forums/showpost.php?p=4341035&postcount=269

Prolly made a little easier because of the engraved lettering.