Zinc chromate

[czakky]

I always heard it was surplus Italian military aircraft primer and Ing. Carcano didn't want the *extra* weight of a top coat. Weren't the fairings aluminum? They would still require some protection form corrosion, yes?

That's awesome! In an age of Rossi's fresh helmet design for every race.

[docc]

 

I always heard it was surplus Italian military aircraft primer and Ing. Carcano didn't want the *extra* weight of a top coat. Weren't the fairings aluminum? They would still require some protection form corrosion, yes?

That's awesome! In an age of Rossi's fresh helmet design for every race.

 

Right? Just think how much faster The Wildman would be if he would only primer his helmet or *take a decent sh*t!*

[MartyNZ]

Just back from the auto parts store where I do a lot of business. Sometimes, it's good to cheer folks up . . .

"What d'ya need today, docc?"

"I'm here to pick up a stripper. . ."

(We got to the "aircraft" part when the howling settled down.

What are you planning to strip Docc? If it is your fairing, is it metal or fibreglass?

Stripping metal is fine, but some strippers are just as good at eating resin as paint. You should take care stripping any composite fairing. If the stripper attacks resin, you can be left with a spongy mess of bleached fibre matting. Maybe you could test a hidden spot on the fairing.

Stripper can damage painted plastic like your fuel tank too.

This is just in case you didn’t know. I'd hate to see a Moderator cry. 

[docc]

 

Just back from the auto parts store where I do a lot of business. Sometimes, it's good to cheer folks up . . .

"What d'ya need today, docc?"

"I'm here to pick up a stripper. . ."

(We got to the "aircraft" part when the howling settled down.

What are you planning to strip Docc? If it is your fairing, is it metal or fibreglass?

Stripping metal is fine, but some strippers are just as good at eating resin as paint. You should take care stripping any composite fairing. If the stripper attacks resin, you can be left with a spongy mess of bleached fibre matting. Maybe you could test a hidden spot on the fairing.

Stripper can damage painted plastic like your fuel tank too.

This is just in case you didn’t know. I'd hate to see a Moderator cry. 

 

Only the alternator cover!   It's not *bad* (I've refinished it twice), but could use a good re-do. I think it will be pretty subtle, down there, in this *satin-green*.

 

I've never thought of doing it in anything but silver or maybe carbon fiber, so this Carcano_{-ZnCrO4  is going out on a bit of a limb for me.}

 

_{Sometimes, late at night, I can see doing (in zinc chromate green) the entire Stucchi (fiberglass) bikini fairing, front fender, a (number-plate) section on the leading edges of the tank, and even the leading edges of the valve covers . . .} 

 

_{That seems pretty radical, so not yet, though!}

 

_{For now, I'm just more concerned I'll mess up the the "Eagle badge" on the alternator cover. Can I mask it off or should remove it for the "refinish?"}

[Scud]

If you're going to use stripper, it will probably migrate to the adhesive or the chrome on that little eagle.  So I'd suggest removing it, which is easy to do. Heat the inside of the cover behind the badge and pry it off gently. I reattached mine with 3M double-sided adhesive foam tape - just cut it a little smaller than the eagle. It's still holding.

[MartyNZ]

This Eagle badge is listed as GU02517700 "adhesive label" in the parts manual. If your badge is grit blasted into an unrecognizable mess like mine is, you could replace it. Brace yourself for the price though.

[docc]

I'm getting 3D prints of sp838's Gambalunga badges ($30US/shipped):

 

http://www.shapeways.com/product/ABDSPQG9A/gambalunga-badges-both-no-steel

[docc]

And I've staged all of the proper, and suitably dangerous, chemistry . . .

[docc]

The alternator cover doesn't really look that bad (or does it? ), but I'm in too deep to back out now.

[The Monkey]

Thats not a stainless bolt holding that cover on is it docc?

Looking good though for a 100,000 mile motorcycle

[docc]

Thats not a stainless bolt holding that cover on is it docc?

Looking good though for a 100,000 mile motorcycle

Guilty. . . . . I'd like to think they have a proper coat of copper antisieze on their threads. The top two are still the original cross-head screws. Not sure why.

 

She has a few *character lines* now, the old girl . . . 

[footgoose]

 

Thats not a stainless bolt holding that cover on is it docc?

Looking good though for a 100,000 mile motorcycle

Guilty. . . . . I'd like to think they have a proper coat of copper antisieze on their threads. The top two are still the original cross-head screws. Not sure why.

 

She has a few *character lines* now, the old girl . . . 

 

What have I done now..... Is there some sort of nasty interaction using stainless bolts in aluminum?

[MartyNZ]

What have I done now..... Is there some sort of nasty interaction using stainless bolts in aluminum?

Stainless steel is corrosion resistant itself, but if two conditions are present, it causes galvanic corrosion on aluminum. These are:

1- electrical connection between the two metals (ie bolted together).

2- an electrolyte touching the two metals (ie salty road spray).

A grease like vaseline can keep the electrolyte out from between the metals. Stopping the electrical connection in threads is harder.

Durable designs usually use cadmium plated steel bolts on aluminum castings to reduce the chance of corrosion. Zinc chromate or zinc rich primer on the SS bolt under the head will help too. Cadmium plating appearance becomes shabby as the plating is used up in sacrificial protection, so SS bolts look like good replacements at first glance, but over time SS attacks instead of protects.

The rate of galvanic corrosion depends on how far apart the metals are on the electronegativity scale shown in this link: http://www.ssina.com/corrosion/galvanic.html

My valve covers are attached with ss screws, but are assembled with lots of grease.

[czakky]

Does anti seize count as "grease" when using stainless to aluminum?

[MartyNZ]

Does anti seize count as "grease" when using stainless to aluminum?

Yes, I think so. Anything that keeps water out would be helpful. Especially if there is enough around the head to ooze out as you tighten the bolt.

I avoid copper anti seize except on exhaust clamps. For general casing bolts I use Parker thread Lube or LPS500.

If you must use stainless steel bolts on aluminum castings, the best product is Duralac (in the UK) http://www.intek-uk.com/duralac_compound_dtd-369b.html or Mastinox (in the USA) http://www.ebay.com/itm/Mastinox-D40-Yellow-6856K-160mL-MIL-P-8116B-FREE-SHIPPING-/322109920293 . Zinc chromate and strontium chromate are both quite toxic so wash your hands after using it. Also they are both yellow, so you need to wipe off any excess or your engine will look bad.