cleaned an engine in prestone and it blackened ... what to do ?
 

I know this can happen ...

prestone possibly too hot ...

is there any way to remove this oxydation ?

thanks

Supe

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

You may have used 50/50 already diluted and that can make it worse.
Not much you can do. Put it in service under a cowl or send it for powder coat.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

Bead blast it carefully and it will look better than new.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

Try boiling it in Vinagar?

If you boil an engine in Prestone it will discolor the aluminum.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

The idea is to simmer the engine in (undiluted) prestone, and it works perfect. I do probably 10 engines a year for friends, and I have never ever had a problem.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

You can use a brass tumbler for polishing ammo brass, you have to take everything apart and be sure all the sand is cleaned out of absolutely everything before reassembly. Depending on what polishing sand you choose, you can polish to a mirror shine or rough metal. You can use walnut or pecan shell instead of sand. This will only remove the oxidation but none of the metal itself.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

Well I would just chalk it up to experience and put the engine back together and use it.  Of course the ugly engines never wear out and run really good too.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

IFLYGLO , I sent you a PM

thank you for your replies gents

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

This won't help now, but I like to use Dawn Power Disolver before they get badly baked on oil.  I do it right on the plane every few flights.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

I have used this and an various brushes starting with brass and then a stiff nylon detail brush. Stainless brushes and this cleaner work well together but watch your edges and it might leave scratchs.

It's water rinse so it flushes out really well and leaves no residue if your careful. Works great with a scotchbrite pad. The compound really helps remove oxidation on brass without touching so it must be a little acidic.

Barkeeper's Friend is also a good product. Look for it in the sink cleaners at the grocery store, same with the copper cleaner. It's like Comet sink powder but different in the respect it etches aluminum nicely to a factory shade.

If you want to do it right it takes elbow grease and taking the whole motor apart. I don't know of any other way without masking and grit blasting.

One note about grit blasting, I personally would oil soak the cases afterwards to lift all the powder out of the aluminum pores with some good penetrating oil. I have done this and its amazing how much aluminum is left in the pools of oil.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

That Dawn Power Disolver is great stuff but make sure you rinse it off with water as it will keep on working and can mess up aluminum engine cases if not stopped with water when clean.


It's almost as good as that engine cleaner Davis Diesel used to sell. Wish I could get some more of that stuff.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

Phoenixangel, would you mind explaining this process a little further? For example, what to use for abrasives, ect.? I have the equipment to do this, and would never have thought of it. Thanks.

RE: cleaned an engine in prestone and it blackened ... what to do ?
 

I clean most of my engines in heated antifreeze. i had an engine turn dark like that and that is because i let it cool over night in the antifreeze. it doesnt hurt the engine at all and if anything it will help it run ever so slightly cooler.