Need Chemist advice!

Jay Lutz

Jay Lutz

Well-known member
I tried to call Dayle Frame but, God forbid, he seems to actually be working today. Tough life.

Anyway, I have a small piece of cast aluminum (12"x6"x1", not sure of alloy but likely not A356.....super soft and almost feels like 1100) that has heavy baked on gummy oil residue....years and years of oil and food, heat, oil and food, heat......and I need to clean it. Stuff I tried or decided not to try...need advice. Help!

* Industrial shot blasting- shot just bounced off and did little
* brake cleaner- no obvious effect
* WD40- my idea was that likes dissolve one another....no obvious effect
* Oven cleaner- decided NOT to try it since instructions say do not use on aluminum. Main ingredient is NaOH which I think is a strong base with a pH around 13+
* carb cleaner- I think the bucket is in our MO house....but it's not in Indy
* May try H2O and white distilled vinegar in pot, boil with aluminum casting in it.....Jan will love that in the kitchen I'm sure. Vinegar is an acid with a low pH

I'm hoping someone can advise some sort of home remedy from basic stuff around the house. Thanks, Jay
 
Is this piece ornamental?

Oven cleaner will strip any anodizing off and possibly leave a white oxide residue on it. If it's ornamental that may not be the way to go. I made the mistake of cleaning a set of wilwood calipers with it one time. it turned the black coating almost a light pink, but it did get several years of brake dust and CV joint grease off. Since I'm too manly to drive around with pink brakes, I painted them silver and called it a day.

Have you tried lacquer thinner? As granny says in the Frank's Red Hot Commercials... "I put that s*** on everything!"

Another thing would be an aluminum wheel cleaner, but I've seen a few of those also attack bare metal- make sure it says it's safe for use on bare aluminum.

What about Goo Gone or some of the other "super cleaners" out there?
 
I've used Easy Off oven cleaner several times on Moroso type anozided air cleaners/valve covers with NO problems at all. It also will clean an engine block to look like new. You can always bead blast it afterwards.
 
OK.....I've also tried the following with NO luck:

* oven cleaner sprayed on and heated to 350F
* heated to 350F and then spray oven cleaner
* Vinegar and boiling water. Soaked for 1 hr this way
* paint stripper

This stuff is like kyrptonite.

Chemists.....how about muriatic acid or even sulfuric acid....both EZ to get at Lowes? I need something that won't react with the aluminum.

Thanks, Jay
 
Jay,

Aluminum is soluble in alkalines (bases, such as NaOH), and also in hydrochloric acid and sulphuric acid.
It is insoluble in nitric acid and acetic acid.
Avoid using oven cleaners and most wheel cleaners.

Grease is organic, and should be soluble in organic solvents. There are dozens.
Prep-Sol (duPont auto product), alcohols, acrylic enamel reducer, acetone, lacquer thinner, benzene, carbon tetra-chloride, toluene, and even gasoline (hexane, peptane, and other HC chains). Vapors from some of these solvents are not good for a person, so be advised. Chromic acid might work, but it is somewhat dangerous.

Try some of the "citrus cleaners", since aluminum will not be attacked by acetic acid. Be sure that they do not contain HCl or muriatic acid ( iron rust remover ) or H2SO4.

Found a reference that used a 1:4 mixture of table salt and rubbing alcohol. This might form HCl ??

Cleaners for air-conditioning condensers and evaporators claim to remove oils and grease, and not attack aluminum, with some not containing any acid.

Charlie Tolman
 
In my parts cleaner I went to using Simple Green Max mixed 50:50 with water. I added a heating element for a hot water heater to the tank to warm the mixture for better results.

When mixed with water Simple Green does not discolor aluminum. Hard to clean parts I let soak over night and then I can just brush the stuff off.
 
Jay, probably what you have there is kind of like a low molecular weight plastic coating with a possible small amount of carbon residue. Over time the heat has driven off the lower molecular weight components leaving the longer chain molecules and those may have even polymerized somewhat along with some possible cross-linking. I know Nitric acid has an effect on most polymers and may be what you need to remove it. Aluminum is not attacked by nitric acid so it will be safe in it. Not much else will be safe around it though including you. The other problem is trying obtain it. It is not readily available. You might try to find an anodize or plating shop that would be willing to work with you. They should have nitric acid.

Any solvents that could have an effect on it would be even more difficult to obtain.
 
I think I'll try gasoline first, then nitric acid if I can find any. Great advice.....thanks everyone. I'll report on progress or lack thereof. Jay
 
Try some paint stripper that contains dichloromethane. That will dissolve most organic residues. I now see you tried paint stripper. Make sure it had DCM.
 
Will the part fit into a crock pot?

Although I have never used this method, I have heard it works great.

Put some anti freeze into the crock pot add the part, warm it up and let sock.

Should be harmless. Although you might want to buy a crock pot just for the garage, don't use the one in the kitchen....
 
comes in a green spray can - CRC Industrial Strength gasket remover - used to remove gaskets from engine blocks and most metals - they have it at O'Reillys - does a good job - should work ....
 
DatsunDoc":37lyh9np said:
Try some paint stripper that contains dichloromethane. That will dissolve most organic residues. I now see you tried paint stripper. Make sure it had DCM.
Click to expand...
That would probably work if you can find it. Dichloromethane is another term for methylene chloride. It is great for attacking polymers, including epoxy, but is very nasty stuff and also difficult to find. Its use is very limited due to the health risks and has been banned for use in strippers in Europe.
 
Gasoline seemed to loosen things up a bit. I'll focus more on this hopefully without setting anything on fire.
 
The hot soak in anti-freeze worked on old model airplane engines.

Engines with basically cooked on old oil, would come out looking brand new. Cooked on old caster oil doesnt normally come off very easily.

Warm soak of Anti-freeze also should be fairly safe.

The same guy that did this also used to put parts into the dishwasher.

We don't eat at his house....
 
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