Fuel bowl white residue

I got a good core Q-jet carb for my 72 350 but the white residue at the bottom of the fuel bowl has been there ever since. Soaked it in the degreaser/Cleaner and it loosened up and scraped most off, but after spraying carb cleaner, it dried up and came back. Any ideas of how to get rid of it completely? please let me know.

 

Could just be oxidized Aluminum? Just guessing...

 

It is some kind of corrosion. Probably dried up fuel and whatever was in that fuel caused this reaction. I'm rebuilding this carb and stuck at this point of how to get rid of it. I have used Marvel mystery oil and seems to prevent but when wiping it off, its back again.

 

Thanks for clearing that, Larry.

 

Yes, I do have to point out that Larry's link explains that it is in fact Aluminum oxide, caused by the alcohol in the fuel.

 

I’m guessing that aluminum oxide isn’t easy to remove completely. So is sand/media blasting the only option?

 

CLR will dissolve a lot of it, but if its established enough to be almost like a rock grain, media blast might be the best method to remove it.

To prevent oxidation on zinc carb castings, chromate the casting and try to limit exposure to air and moisture. There's only so much you can do.

 

I will try to give CLR a try but also heard krud kutter works good too, haven’t tried neither yet. Here’s pics when I got the core before and after cleaning/soaking with a parts degreaser and cleaner.