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anodizing


Guest callithrix

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Hrmm, dunno... sounds interesting and easy, but like a lot of things, I bet it harder than it sounds to get a consistent finish, and there's a reason professionals do this more often :P

 

Sounds like it would be cheap to just give it a try though, kinda like a science project :thumbsup: ...after all, it's only about $100 if you don't already have a 12V charger/source. I'd love to try this one day and/or hear about someones' results.

 

 

But here's something interesting... unless you are going to anodize some billet part on the bike(point to one for me if you find one :P ) ...most of our aluminum parts are cast, and won't take too well to being anodized. Because of the impurities, you'll end up with a splotchy black result. That's why parts like the valve covers, side plates, etc... are painted/coated from the factory instead of anodized.

 

 

So, on that note, I just got my side plates and valve covers back from the powder coaters, and the "lollipop candy" finish is awesome(although it's a bit shinier than I would have preferred...)! The coaters had some real headaches with the valve covers though(now I know why MG paints these parts versus coating) because the porous castings "gassed out" a lot, and the guys at the shop had to keep sanding and recoating to get the bubbles to stop. Even after a couple passes, I've still got one or two little pin-prick bubbles that came through. But you wouldn't notice from a distance.

 

I'll post some pics later...

 

al

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Guest callithrix

That was my intention. I was thinking of trying it on a pair of extra barends. I'm too cheap to buy the red vaive covers so i picked up some hi temp candy apple red spraypaint at the local Kragens. It's little darker than the side plates but I think i like it.Thanks for caveat on the aluminum castings. I'll post some pictures if I'm happy with the results. :bike:

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I'll be very interested to see how your painted covers turn out. Heck, if you like the color, even if they chip, etc... repainting them once a year is a breeze, and cheap :thumbsup:

 

I just repainted my alternator cover with Rustoleum's version of "Hammerite" silver, and it looks pretty spiffy. Road debris had done a pretty good job of chipping the stock silver paint to hell :rolleyes: It's amazing how dinged up the little silver eagle badge even is from rock impacts.... ouch :huh:

 

I tried to hand polish it, but the casting was too porous and had too many defects. If I had used a power buffer, it might have worked, but I just painted it instead. I'll probably just keep repainting the cover in the back of my mind as a yearly refresher thing. It takes about an hour to strip, clean, and repaint.... so no big deal.

 

Oh, and after Feb(engine rebuild) and I put on the new coated side-plates and covers, I should have a "spare" set of powder-coated red valve-covers, and stock red side-plates for sale. I haven't decided yet if I want to keep them for a future color project or not...

 

al

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Porous castings just about covers it. Mike Rich says that Moto Guzzis have the poorest quality castings and grades of aluminum in the motorcycle industry. To that end, my transmission case has not been able to be revived thus far, although I have some hopes that it can be repaired. More likely, I will be buying a new case and rear plate in the near future. I wonder if MGNA can obtain one in less than a year. I really, really fear for the owners of the MGS01 when it arrives as the swingarm is entirely reliant upon the strength of the transmission case for mounting - and that case is not particularly robust. There's going to be some spectacular failures if the current transmission casting is the one being used on the production bikes.

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Callithrix,

 

I do some home anodizing. It's really not too bad, but you need to invest in some equipment and some chemicals. Got a University near you? It'll help.

You can buy chemicals from Caswell:

http://www.caswellplating.com/

I'd recommend buying the metal-based dyes rather than using organic ones (like RIT, from a grocery store) because the organic ones will fade with time and heat.

This fellow wrote up a short how-to on anodizing:

http://www.focuser.com/atm/anodize/anodize99.html

Twelve bucks for a booklet. I bought it, and it is helpful. The info is moslty out on the web, but shoot- 12 bucks (mmm, just noticed- new edition- $17). I like to support the home-craftsman, so I bought two and gave one to our machinist here at work.

 

I gotta say, it is pretty darn cool to take a soft aluminum part and turn it into a super-hard aluminum part. I haven't done any motorcycle parts yet, but if someone wants to send me a valve cover, I would try it for them. Do NOT send me your only good valve covers. I would practice on a busted one first. Frankly, I don't hold much hope for it working since not only are the castings porous, but they contain a lot of impurities and that is what really mucks up the anodizing process. It's a matter of competing electrochemical processes.

 

Cheers,

Jason

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Guest callithrix

Thanks for the tips JRT I work at a University so procuring the chemicals is simple matter. I'll probably be experimenting this weekend. :nerd:

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I have a spare set of V11 Sport fork tubes that I am thinking of anodizing gold (just 'cause I'm too cheap to buy a set of Ohlins)..Are your comments about the metal being too porous applicable to the fork tubes? TIA :rasta: Joe

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I was thinking of anodizing a set of rocker covers just to see how a poor casting will come out. If I remember correctly, if you polish the aluminum to a mirror finish and then have it anodized, the color will have more shine to it. Anyone else know anything about this?

 

Thanks,

Mike, Finally back on line!

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The problem with the rocker covers, and some other pieces, is not so much that it's porous, but it also contains non-aluminum contaminants and that screws up the anodizing proceedure.

If you're going to anodize and you want a nice smooth surface, then the substrate HAS to be really, really clean and REALLY REALLY smooth. Anodizing basically magnifies any defects, scratches, holes, etc. When a part is anodized, all that's happening is that a layer (a few thousand's of an inch thick) of aluminum oxide is grown on the surface of the aluminum. That means the part grows too by the way. Take that into account if it's a tolerance fit.

The oxide is porous, so right after anodizing, you soak the part in a dye. The dye migrates into the pores, and the part takes on the color. Then you 'seal' the aluminum surface- warm water does a fine job of this, or steam works well too. Then the dye is trapped in the pores, the surface is covered with aluminum oxide (super hard) and hopefully it looks good. The few pieces I've anodized have turned out great, but it's all about surface prep.

Porous aluminum would look pockmarked or blotchy when anodized. Low purity aluminum won't anodize at all. The impurities will be oxidized rather than the aluminum. One might be able to desmut the aluminum beforehand, but I havent had a chance to ever try this. I'm still looking for a set (or one) valve cover to experiment on. Need not be in good shape, could be broken, cracked, whatever.

 

 

Cheers,

Jason

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