Removing Copper Corrosion (minimal metal content)

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A tip I read about cleaning carbs was putting them in an ultrasonic cleaner as a whole unit. Thought to myself it would be a good excuse for getting one (ultrasonic) and then I'd further investigate what to use in the tank for good results. I've torn down, cleaned a few carbs in my day but would love a different method that works well😉 Just a bit of info<shrug>

Jim is the resident chemist that might have some cleaning brass corrosion ideas...

My neighbor puts carb stuff in a small container of gasoline (with a lid) then sets that container in an ultrasonic with another liquid (forget what he uses , maybe water?) . He says gas works better than most "cleaning solutions" but he doesn't want the gunk in his cleaner - or the possibility of a rapid deflagration . I have added him to my (very short) list of people who are allowed to work on my stuff .

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Maybe I'd try this outside while watching with a CO2 extinguisher in hand. Pretty sure it would be a last resort, Hail-Mary kinda thing though...

I've wanted an ultrasonic cleaner to experiment with for years. Stories I hear sound too-good-to-be-true...

Jim is the resident chemist that might have some cleaning brass corrosion ideas...

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Ammonia, but it can be too aggressive to the metal as well. I lost a car radiator to/from sitting open in a horse stable while I was getting the head repaired after the timing belt broke. Now I change the belts on schedule religiously (on my knees).

I haven't tried this:

Vinegar plus Dawn slowly attacks soap scum in the shower.

The carb crud problem I see is a clear gel that dries to a white powder. Supposedly it is aluminum hydroxide dissolved from the castings with the help of ethanol and water.

Usually in carburetors I see brown black gunk that is dried and hardened fuel additives left after the benzene (and alcohol) evaporates.

This is clearly green copper corrosion growth on the brass pickup tubes (and a brass orifice in the base of the bowl. These look like your typical zinc alloy casting, so damage to the carb body is a concern. I'm not going to arc test it to see whether or not I get a pink arc, but that's my guess. There is no sign of lead contamination deterioration or other carb body erosion so its a properly made casting. Being on a

2005 engine that makes them 18+ years old. Plenty of time for bad manufacturing methods to show up. Not cheap carbs you can buy on Alibaba for next to nothing for your vintage mini bike.

I use Citric Acid for iron&steel parts. Have some brass I need to clean, I might try that and let you know how it goes.

Citrates are easy to remove and/or are soluble, unlike some acetates. Better all round.

Clifford Heath

Not sure about the ammonia suggestion as it attacks the zinc in brass and is what some people I know use to make brass go green when they want that patination.

Vinegar would be a better bet or a condiment containing it. A woman I know swears by tomato ketchup for cleaning her horse brasses.

Pine-Sol is another organic acid that is worth a try. I've used it to clean motorcycle carburetors. Full strength cold it doesn't do much, but as it's heated to boiling it gets visibly aggressive. No ultrasonic action required, but it would probably help. Don't leave valuable parts unattended.

No fire hazard, but the "original scent" version _really_ stinks when it's boiling. I used an electric hot plate in the back yard, the smell was noticeable out front.

The active ingredient is glycolic acid, which is in some degree like soap: The acid part is attracted to water, the glycolic part is miscible with organic compounds.

Good luck,

bob prohaska

"Back in the day," we used to fill the parts washer behind my dad's hardware store with kerosene, and we used kerosene as a cutting lubricant for scoring window glass to cut it to size for customers. I cleaned a lot of engine parts and more than a handfull of transmission parts with kerosene. For particularly nasty parts I was known to hand wash with gasoline. A mop bucket half full of gasoline did wonders. When I was to that point we were post lead, and pre-alcohol for gas. I may have also played with a little gas. If you get a good vapor cloud you can ignite it with a spark, but you need a hot spark. It doesn't spontaneously flash. I've seen guys put a cigarette out by flicking it in a bucket of gasoline, but I think that would be risky on a hot summer day when the gas is almost visibly evaporating. Gas(benzene) is scary, but not quite as scary as its made out to be. Not like acetylene. I have seen acetylene ignite without a spark. I think I described the circumstance on this group not long after it happened.

I would still use kerosene in my parts cleaner, but I keep it outside where it evaporates before I can use it again, and I don't have 55 gallon barrel of it out back to fill cans for customer's lamps like we did, "back in the day."

Not sure about the ammonia suggestion as it attacks the zinc in brass and is what some people I know use to make brass go green when they want that patination.

Vinegar would be a better bet or a condiment containing it. A woman I know swears by tomato ketchup for cleaning her horse brasses.

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I tried ammonia on corroded brass only once, in a Ziploc bag so I could squeeze the air out. Without oxygen it cleaned the brass, with it the brass corroded again.

Many molecules including ammonia can bind to metal atoms and make them water soluble, the way soap does to oil. Some are weak acids like citric or oxalic, but their acidity contributes less than their binding ability.

Plant and animal life depends on this nitrogen to metal bonding, in plants as chlorophyll and in animals as hemoglobin, which are quite similar.

Some invertebrates and Vulcans have a different, less efficient copper-based blood oxygen carrier. Evolution has produced more than one solution to the same problem.

Cleaning carburetors is sooooo much fun. As I was cleaning number 2, I realized I never cleaned "this passage" on number 1, so it comes back apart again.

It must be fun. This is the third time I've been inside number 1 TODAY.

By the time I finish #3 I might figure out everything I need to clean and degunk.

My neighbor does some small engine repair/tune-up . He uses a small container of gasoline submerged in water in his ultrasonic unit to clean carb parts . He's got one of my chain saws right now for a carb kit (yard sale buy that sat for years for cheap) .

Of course as I was sitting there putting number 1 back together again I couldn't help but wonder why there was a main jet setting on the work bench. I guess in my hurry to get #1 apart and back together again I rushed a wee bit on number 2. I am now about to pull #3 apart again for the first time today. LOL.