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Discussion Starter · #1 ·
NOTE: I had made a mistake on this posting in that Alodine is not the same as Zincate--Zincate zinc converts aluminum, Alodine chromate converts but the process discribed is my work with Alodine. CB200

You guys asked so here are pictures of painted Honda covers that were chromate touch-upped via Alodine. Honda had plated these covers in the first place so the alloy is one that love's to pick up chromate and zinc. I strip with a methylene chloride stripper (aircraft paint stipper). Wipe with MEK, degrease with liquid dish soap. Then any surface in question I scrub with Brown Scocth Brite till it shines-rinse-brush on undiluted Alodine-(Brush with the Scocth Bright strokes). You'll see it convert before your eyes it will change from bright aluminum silver to a duller metalic gray. But the aluminum must be just cleaned, scrub-rinse-Alodine-don't stop for a cup of coffey. You should paint asap too so the chromate hasn't reacted with the elements-but it's not critical like the aluminum reacting with air. One doesn't need to use a zinc paint on primer-it's already plated! If primer is part of the base coat coloring then you'll need to.[attachment=3:2bk5qok4]DSCF0621.JPG[/attachment:2bk5qok4][attachment=2:2bk5qok4]DSCF0622.JPG[/attachment:2bk5qok4]
The top cover has been tested by running at standstill @2500 RPM for 1 hour each time with 5 repetitions. It now has 600 miles and about 18 hours road time.[attachment=1:2bk5qok4]DSCF0623.JPG[/attachment:2bk5qok4][attachment=0:2bk5qok4]DSCF0625.JPG[/attachment:2bk5qok4]
This is an example of what happens if you don't get the oxide off before Alodining. Most likly I scrubbed the top and the side but did not concentrate on the radius. The metalflake paint is recent paint but I've had some 12 year 25,000 mile stuff. The paint comming off the chromate is not an issue. Like I said Honda ether zinc plated or chromated this stuff in the first place so the alloy is one that zinc and chromate plates easy-just get it cleaned of oxide first and brush on the Alodine. There is also a product called Zincate-similar stuff it plates zinc in stead of chromate .
 

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So why not just prime and paint then? Or powdercoat? What's the purpose of this plating before painting?? Seems totally unnecessary to me...?

Every factory Honda cover I've ever refinished has never had any coating of zinc. Only a clear coat over the aluminum itself..


Please elaborate..



GB :mrgreen:
 

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First, thanks for the pictures, they look good.

GB got to the question first but let me elaborate. Your use of the term Zinc Plate does not make sense since there is no zinc involved.

Let me try and paraphrase your process. You strip the old finish (lacquer or paint), clean thoroughly, alodine, paint (using a two part paint) and then clear coat? Does that sound correct?

The process of using Alodine, which is a trade name for a chromate conversion coating, provides a barrier to corrosion prior to painting. This process does not convert anything to a zinc coating or apply a zinc coating since there is no zinc involved. The factory may very well have used an Alodine type of process prior to applying a lacquer or paint coating, I don't know. The factory screws have a zinc coating as do various springs and brackets but not the cases or the case covers.

In the picture of the sprocket cover, it looks like you have a paint run and doesn't have anything to do the paint lifting from the alodine layer.

Your cases look excellent although they don't look stock due to the metal flake paint. The top cover looks very nice and has more of a factory look. Good job.
 

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Discussion Starter · #4 ·
Because I have been working with a product called Zincate as well as Alodine I have the fact that Zincate is zinc and alodine is chromate blurred. So I got a plate of crow comming on this one. Onething for sure Honda covers of the time really take the conversion well. If one is going to strip, degrease, sand, and prime then a conversion prime instead of paint on prime is the thing to do as: its easyer, it will not run, or sag, or orange peel , and for aluminum it is the primer and protectant. If I was more web learned I'd give a link but search alodine, read the EAA page-it was from my EAA days I first learned about alodine and that was way back and how I got my Zincate and Alodine blurred. No I did not use Zincate to paint prime-Alodine. Zincate is what one uses in just the same way to electroplate aluminum. Rather than go off redundantly check the EAA posting (EAA-Experimental Aircraft Association) The FAA lets them handel most of the FAA's own job when it comes to home built aircraft.
The lower covers are not intended to be reproductions of the original finnish. At a short distance without a camera flash they look almost like OEM but with somehow a little more eye appeal-now you now the how in somehow. I am working on all original parts for show only too. The bike came 12 years ago with Candy Gold Metalflake and gold CB200T covers. But it's a 73/74. Made in 73 but most call'em 74's--it should not be Gold. Well except for show only it's gold, a tad customised there too. I have Muscat Green side covers with proper insignia's. So the extra tank will get a new gold paint job-- latter I'll get the current tank (it's in better shape so it gets the OEM treatment) a decal and then I'll match it to the green side covers.
The paint job on the top cover is clear coated-not oem-but the aluminum paint is gas intollerent. The first clear coat tried, Krylon was gas intollerent. The current-Aluminum Wheel Clear Coat-Duplicolor, seems more gas tollerent but the jury is still out. It is too soft even weeks after it is sprayed on it will develop swirl marks if you rub it-- even dust free.
I could of used a singel stage low luster aluminum powder paint to match OEM on these covers but this is the bike's everyday trim. I don't run my pre EPA mufflers- but my everyday ones are CB200's-I'm saving my gray cable set, but my black ones are Honda CB200's--my reproduction seat cover will fool all but a CB200 freak-my OEM used only once seat even I don't sit on. I've already set aside a rear wheel hub and my polished rear hub's gonna look even better when my extra front hub shows up and I'll polish one of them front ones up to match it, just like I did one set of forks. At 10 yards even a collector doesn't know somethings up with the bike's finish maybe "damn he's got that thing polished up good" at 10 feet he'll know at 3 feet he'd see it all. Clear coats! Custom metalflake size! Polished! CHEAT-CHEAT-CHEAT
Bite me!
 

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I personally don't see the advantage to your complicated processes... It seems to me that Honda, just after casting only clear coated the cases... I tend to think that after a good cleaning of the factory cases, a person could simply clear them with an automotive (two part, fuel safe) clearcoat, providing a show worthy finish, without any zinc coating mumbo jumbo...?

But then, I'm a "newb"... :lol:


GB :mrgreen:
 

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Ok gents from a previous post of mine ;)

Lets just clear this up, Alodine is a chemical conversion coating the bonds to the alloy surface. All alloys in there raw state are quite acidic and start to oxidize within seconds of being exposed to air. Paint require a neutral surface to adequately adhere to the alloy, so we treat the surface to make it chemically neutral with "aolidine 1200s" or an etch primer, which, strangely enough etches into the alloy and is very reactive to most paints so "this is good".

This process is the same for all alloys on motorcycles, car, aircraft, etc

Step one - clean the alloy part with a solvent to remove any contaminates M.E.K, Acetone, etc

Step two - clean the part with mild scotchbrite and a detergent cleaner that has a % of chromic acid (usually only 10%), you can buy this from "good" paint supplies, deoxidine 624 (turco), metal bright, etc. This removes the corrosion and any other gunk from the surface. Remember that the alloy will start to corrode straight away.

Step three - Alodine the surface straight away in accordance with the manufactures process.

Step four - Paint as required and follow the manufactures process.

If you do this the paint will stick to the alloy part like **** to a blanket

Remember that the internet is full of so call experts so take the information and then do your own research. Even the info I have given here.

Do it right, do it once

Sorry :oops: :oops: forgot to enlighten the brotherhood on Zincate. It is a chemical solutions that is alkaline used in a dipping process to plate aluminium with zinc prior electro plating (any plating) also great for painting.
This immersion process is electroless (i.e. not electroplating) and involves the displacement of zinc from zincate by aluminum, ie it coats the alloy with a fine (read, bonds at a molecular scale) zinc coating just by dipping.
By using the Zincate process as a pre-paint dip, you chemically remove the oxide layer and at the same time, apply a layer of zinc. The zinc protects the aluminium until it is ready to be painted.

Rod from OZ :cool:
 

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Discussion Starter · #7 ·
He made a good point-after I Scotch bright the worst of the oxide off I too wet the Scotch Bright with a little Alodine to finish the job. (I don't know what the % of chromic acid is in alodine) This way the amount of time the clean aluminum has to react with oxygen before it is covered by alodine is "0". Alodine not only makes the paint stick better it vastly improves the corrosion resistance of the aluminum-if I had the know how to post a link to the EAA web page on alodine I would, and it will fill you in on this and more.
 

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otr002 said:
or an etch primer
Are all etch primers heat resistant?

Doubt I can get any specific brand that you guys might be using, so useful to know if I can just grab any.
 

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I was stationed on a cutter for a few years, it had an aluminum super structure, and we painted a lot! after approximately 10-15 months it would flake right off the stuff was psx 700 as I recall, it ran about 100 a gal and looked great, hard as hell.. till it fell off the boat, the psx seemed to adhere better to the bare aluminum than the red primer the yards had sprayed the entire thing with after a complete sand blasting. but both the primer and the top coat would flake. there might be something to this alodine stuff..
 
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