Help - Engine staining due to cleaning
 

Hi all;

I have a bothering problem regarding an OS AX .46:

I got a badly varnished and gummed engine (on the outside), which looks like new on the inside.

The engine was used on a trainer, and left over un cleaned for a quite long period of time (not by me – I treat my engines much better).

I took this engine apart, examined it’s parts, and apart from it’s bearings which are being replaced with new ones, everything seemed to be in a perfect condition.

In order to properly remove all of the gummed and “fossiled” dirt off the engine, I took the following action:
I dissolved a tablet of dishwasher cleaning agent in warm water and soaked the engine Aluminum parts in it.

The dirt dissolved in minutes and was very easily removed off the engine – great outcome so far.

But…. All of the engine Aluminum parts (muffler, engine head, carb. body, engine body) got severely stained – the Aluminum was discolored from it’s natural silver-like color into a Led-like dark gray color.

Please – if anyone knows of a method – other than mechanically rubbing this layer of staining off – to remove that ugly gray staining – share the info

Thanks in advance

Yaron

RE: Help - Engine staining due to cleaning
 

That's what happens when you use a alkaline cleaner on die cast aluminum parts. You are just going to have to live with it.

Aluminum must be cleaned with near neutral PH cleaners. Slightly acidic or slightly lower than a PH of 7 is OK.

Even mildly alkaline ,PH slightly above 7, will cause staining of the engine block.

Also antifreeze is good cleaner for model engines but if you boil the antifreeze with the engine in the solution, it will also turn the aluminum grey.

RE: Help - Engine staining due to cleaning
 

Dear w8ye;
Thanks for the info - I sure am sorry for not consulting earlier...
Is there any chemical (acid based maybe) that might lighten up the color of the aluminum?

Thanks again

Yaron

RE: Help - Engine staining due to cleaning
 

Nope, not anything that won't also start to corrode the aluminum, as far as I know.

RE: Help - Engine staining due to cleaning
 

------------------


If you ever wanted to experiment with painting and prettying up an engine, this might be the one to begin with.

I had an Enya 60-4C that needed a bearing replacement. A good friend, whose occupation is farm equipment mechanic, offered to replace the bearings for me and to throw it in his engine parts cleaning vat for me to remove the baked on castor oil. This was about 15 years ago, before the current crop of non corrosive/staining cleaning compounds was available. The engine came out of the cleaning vat a much, much darker grey. It didn't look bad, but it didn't look stock.

I reassembled it and it ran fine without incident. It just looked strange.

I live in the USA and we have recently encountered a product called Dawn Power Dissolver. It is a gelatenous liquid that is sold in a spray bottle. It works amazingly well at removing varnish stains from model engines. If you have an equivalent, it might be worth your time to try it. It might help, or it might do nothing at all. It's also great for pots and pans too.

RE: Help - Engine staining due to cleaning
 

Dawn Power Dissolver is slightly alkaline. Therefore it should not be left on the engine for two or three days or the engine boiled in a solution of Power Dissolver.

Power Dissolver usually does what it is going to do (cleaning with that application) within about 30 min.

RE: Help - Engine staining due to cleaning
 

Thanks friends;
I will look into this Power Dissolver
Hope it'll be available here in Israel

Best Regards

RE: Help - Engine staining due to cleaning
 

Go for it! :D

RE: Help - Engine staining due to cleaning
 

Perfect Engine Cleaner from Chevron products works very well and does not discolor aluminum. I heat it to boiling and soak parts in it. It removes organic materials (grease and burned on oil) very quickly. It's all I use. Sheldon's sells it. Comes in 1 pint platic pottles.

Part of post removed by moderator....

RE: Help - Engine staining due to cleaning
 

-------------


I wiped my clean immediately, after getting the results I wanted. I never thought of leaving it for a long time in a solution of this liquid. Thanks for the tip.

RE: Help - Engine staining due to cleaning
 

There is a product that anodizers use called a "desmutting" agent. Contact an anodizer and see if this liquid can help. It is the last cleaning stage before the anodizing process.