Cleaning corrosion from zinc

Have you tried a fine cupbrush on a grinder?

Gunner

One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch

ATTABOY!!!

A fine (.008", .006") powered wire brush. A small cup brush, "solid-fill endbrush", or a "pencil endbrush" will do a great job without damage.

This is a carburator so there is no way a cup brush could be used on/ in it without destroying something

This is a carburator so there is no way a cup brush could be used on/ in it without destroying something

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WRONG! I have wire brushes that would take the skin off a peach and not scratch the flesh.

Was there a lot of bubbling when you tried the muriatic? Any zinc would have dissolved while making hydrogen gas.

I suspect Gerry has little contact with decent American made wire brushes.

Perhaps a link to a damned good vendor...

He may well pay some attention to ...End Brushes

Gunner

One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch

Then go to a welding store and purchase a stainless steel "toothbrush". They're used for welding aluminum, cost a buck or so.

I do not want to brush it off. There are too many areas where even a tiny brush will not reach and still be stiff enough to remove the corrosion. This is why I ask for a way to CHEMICALLY remove the corrosion. Looking for a proper dip or soak. Thus far I have tried Berryman carb soak. Got the carb clean but did not touch the corrosion. Next I tried vinegar-no good. Then CLR-still no good. Next was lemon juice-a small improvement. Then came soda/cola-with about the same results as lemon. Muriatic was way to aggressive on the base metal to use for long. Next on my list is phosphoric acid, and then alkaseltzer or Polident. The whole object is to get a good, even finish and dip or media blasting is the only way I know of being consistent. I really don't want to have to blast a carbs internal parts with any kind of grit for fear of plugging tiny orifices up. My gut tells me a mild acid is the way to go because I suspect the corrosion itself is probably basic. I think it's a matter of finding the right one/ones. Surely with all the knowledge in this group someone else has been here before

I do not want to brush it off. There are too many areas where even a tiny brush will not reach and still be stiff enough to remove the corrosion. This is why I ask for a way to CHEMICALLY remove the corrosion. Looking for a proper dip or soak. Thus far I have tried Berryman carb soak. Got the carb clean but did not touch the corrosion. Next I tried vinegar-no good. Then CLR-still no good. Next was lemon juice-a small improvement. Then came soda/cola-with about the same results as lemon. Muriatic was way to aggressive on the base metal to use for long. Next on my list is phosphoric acid, and then alkaseltzer or Polident. The whole object is to get a good, even finish and dip or media blasting is the only way I know of being consistent. I really don't want to have to blast a carbs internal parts with any kind of grit for fear of plugging tiny orifices up. My gut tells me a mild acid is the way to go because I suspect the corrosion itself is probably basic. I think it's a matter of finding the right one/ones. Surely with all the knowledge in this group someone else has been here before

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I have not been there before. However, a quick Google search turns up several things. One is a 10% acetic acid solution. Another is a "dilute" (how dilute?) solution of HCl (muriatic acid). Then there are some real beauties that sound like they were cooked up by a chemistry Ph.D, including tartaric acid, mercury compounds, and other crap that is coming nowhere near

*my* shop, bubba.

There also is a caustic soda (lye) solution recommended in one engineering book. It's a combination of chalk (probably just to make it stick; I'd use diatomaceous earth, which I keep around for just such purposes) and 20 - 40 parts by weight of lye to water. Hell, that's the dilution I use for cleaning the drain pipes in my house, and it eats up all kinds of things.

I have used a bristle brush on my Dremel -- no wire -- to clean up an old diecast fishing reel. It worked well enough. I've never tried the acid solutions, however. I've used HCl to clean the galvanizing off of EMT, and man, it eats that zinc very fast.

Good luck. Don't eat your carburetor while trying to save it. d8-)

I believe aluminum alloy carb parts generally have a surface protection treatment, and when the "coating" is compromised, the underlying metal is unprotected, and rapidly attacked by oxidation and any other compound that gets near it.

You may be able to strip the white "blooming" away, but without the protective skin, I think it's likely to resume blooming/corroding as it gets exposed to other materials.. a little water in the gasoline, etc.

If you're adventurous, try blasting the area (low air pressure) with table salt or other granular material that will dissolve quickly for cleaning after blasting.

I forget what causes the white crystallization of aluminum.. a salt maybe (so salt may be a bad choice), and if treated with a base, the white corrosion may be able to be cleaned away effectively, but that doesn't mean it will be stopped. I've seen these same spots on chemistry lab stands, bases/parts, but those parts can often be repainted after the corrosion is cleaned away.

I think there is probably a method for restoring antique carb parts' protective layer, so possibly, old car enthusiasts may have an answer.

I had an electric motor at the back of a bench, which sat in contact with a sandstone wall for about 2 years (below grade and the wall had been coated with unknown products). The end bell of the motor was an aluminum alloy, and a considerable area of that end bell rotted/corroded away by the time I discovered it. The hole was large enough that a golf ball could've passed thru it, so compounds in the stone or the flaky coatings rotted the aluminum. White, crystalline residue around the hole.

Gerry, I just had a thought. It's not an informed thought; it's little more than a guess. However, I'd try it myself, if I were you.

This is an electrolytic cleaning method that I've used very often for rust. The author of these instructions, Ted Edwards, always seemed to know electrochemistry very well. He uses it on a lot of different metals, to remove corrosion:

You may be able to get away with just the washing soda; I don't know. I use the exact formula that Ted recommends, but a similar process, done in a bucket, uses just the soda (Arm & Hammer Super Washing Soda. I don't think "super" means anything here.)

I use a little 4-amp battery charger for power, and I have a slab of graphite I use for an electrode. You can get a carbon stick from a welding shop. They're used for carbon-arc heating and brazing. My slab is an old piece from an EDM electrode -- pretty pricey if you were to go out and buy one just for this.

It's really simple. And it's *very* effective for removing rust without using acid. It's worth a try, IMO.

I use Easy-Off oven cleaner. Don't leave it on for long.

Kevin Gallimore

I'd go with the phosphoric acid treatment. I think the carbs, I've had 6 Dellorto DHLA, are aluminium rather than zinc alloys but I've not had to do much cleaning of them. Saying that I've always found a phosphoric acid based cleaner works very well for cleaning off the powdery corrosion from various aluminium alloy products. I've used Jenolite, a rust remover, and alloy wheel cleaner with equal results. Alloy wheel cleaner being far cheaper and bought by the gallon. I've not found it attacks the underlying metal, I would be concerned that the like of HCl would.

Another chemical to try might be Sparex. A close facsimile to Sparex (if not identical) is sodium bisulphate, it's used to adjust pH in swimming pools and as a pickle in jewellry making.

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