Author Topic: Crock pot cleaning discoloration problem (Read 3571 times)

Terry Caron · « **on:** January 06, 2015, 01:33:01 PM »

Hi all -

Cleaning a used engine, it came out a darkish matte gray.
Prestone anti-freeze, high heat, ~15 hours overnight.
That's several hours longer than I usually leave one and I added fresh to used anti-freeze.
Either of those the cause?
Any suggestions to remove the color?

Thanks.

Terry Caron

Jim Kraft · « **Reply #1 on:** January 06, 2015, 02:47:17 PM »

It might have been the high heat that caused it. I usually just use low heat but sometimes with a really dirty crudy castor baked engine I will use high heat for a couple of hours to start the cleaning process. I do not know what will restore the original finish. I think I might try PB Blaster from Walmart and wipe it down with that. Maybe some others have more experience with this.

Terry Caron · « **Reply #2 on:** January 06, 2015, 03:31:39 PM »

Tnx for the tip Jim - I'll try PB if necessary.

I have some commercial carburettor cleaner and I have the head and backplate in it.
It won't damage brass jets or Zamac-type alloys so should be safe.

More later.

Terry Caron

Andrew Hathaway · « **Reply #3 on:** January 06, 2015, 03:54:26 PM »

I've turned several parts murky gray, but every time I post a warning on a crockpot thread a dozen people tell me it's never happened to them.

So anyway... Yeah that happens, it's worse with some engines than with others, Foxes usually are fine, OS and Super Tigres turn ugly. Chances are pretty good that either your temp was too high or you left the parts in the pot a little too long. I haven't found anything that removes the gray. Last time it came up someone suggested soaking in lemon juice, but I haven't tried it. As a general rule I just don't crockpot anything with painted, anodized, or plastic parts, or anything that I don't want to turn murky gray. Let us know if you find anything that works for removing the gray. Also what engine were you cleaning?

Terry Caron · « **Reply #4 on:** January 06, 2015, 04:40:09 PM »

It's a TT .46 Pro, Andrew, and inarguably parts can turn gray.
Also, I remember an O&R that turned a dull greenish color a while back.

FWIW, the carburettor cleaner (liquid, not a spray) didn't do anything.
I'll note, tho', that the stuff is maybe 8 years old and is likely severely deteriorated, so fresh might do the trick.

I'll try some other stuff and post results.

Terry Caron

Dane Martin · « **Reply #5 on:** January 06, 2015, 05:38:25 PM »

Make sure you're using ethylene glycol, not propylene glycol for your anti freeze. That's usually why discoloration happens. 15 hours is a little too long. I'd do like 4. After the discoloration happens, soak the parts in lemon juice. It will clean the stain out of the metal.

Terry Caron · « **Reply #6 on:** January 06, 2015, 05:50:10 PM »

Quote from: Dane Martin on January 06, 2015, 05:38:25 PM

Make sure you're using ethylene glycol, not propylene glycol for your anti freeze. That's usually why discoloration happens. 15 hours is a little too long. I'd do like 4. After the discoloration happens, soak the parts in lemon juice. It will clean the stain out of the metal.

It's ethylene, Dane, so guess too much cooking.
I have the head in lemon juice now, so I'll report results later.

Terry Caron

p.s.: bleach doesn't work.

RandySmith · « **Reply #7 on:** January 06, 2015, 10:35:58 PM »

Dirty , used antifreeZe will cause the motors to turn ugly, use fresh antifreeze, and do not leave it in over 8 to 10 hours, many times on high heat 6 hours is sufficient

Randy

Terry Caron · « **Reply #8 on:** January 06, 2015, 11:22:37 PM »

OK then, live and learn, right?

Lemon juice didn't do anything noticeable, nor vinegar nor hydrogen peroxide.
However, after scrubbing it down with a stiff bristle brush, the color evened out fairly well and it looks pretty good, just a bit different.
Still, next time, fresh anti-freeze, shorter time.

Now, some warmer weather and I'll see how it runs.

Thanks guys.

Terry Caron

frank mccune · « **Reply #9 on:** January 07, 2015, 06:19:22 AM »

Hi:

This happened to me. I placed the stained parts in my vibratory tumbler that I used for cleaning brass shell casings and the parts came out very shiny. One warning!!!! Be sure to plug all screw holes prior to thumbling. If not, the grit will pack into every hole and be tough to remove. I used walnut hulls and a very fine polish. Perhaps a different media would also work.

Good luck,

Frank McCune

Paul Smith · « **Reply #10 on:** January 07, 2015, 07:10:10 AM »

All aluminum is not created equal. Some engines have turned dark for me. But I got rid of the baked castor oil.

Terry Caron · « **Reply #11 on:** January 07, 2015, 01:20:01 PM »

Sad to say, I didn't have the success with my brass tumbler that Frank reports.
I ran it for 2 hours with straight walnut hull medium and no appreciable results.
How long did you run, Frank?

I'll note that clearing jammed medium out of all the fins is a PITA too.

Terry Caron

frank mccune · « **Reply #12 on:** January 10, 2015, 08:38:53 AM »

Hi Terry:

I ran my tumbler for 24 hours. The walnut media had a heavy dose of rouge abrasive. Perhaps this is what is needed.

I have various sizes and shapes of steel tumbling media that I did not try. I also have ceramic media that is quite coarse and abrasive but I doubt that it is small enough to get into corners.

Yes, cleaning the rouge out of the screw holes in the case was a real hoot! Lol

Stay well my friend,

Frank

Terry Caron · « **Reply #13 on:** January 10, 2015, 03:36:01 PM »

Tnx Frank -
I don't have any abrasive additives but PITA or not, I'll do another run for 24 hrs w/fresh medium and see what happens.
I don't suppose it'll run any better if shiny & aluminumy (or aluminiumy, for those across the Pond) but maybe it'll look nicer.

Terry Caron

Terry Caron · « **Reply #14 on:** January 11, 2015, 04:55:26 PM »

So just to update, the 24 hr run made little difference, but again it doesn't really look bad, just different.
I'm ok with it.
But I think Frank is right that a mild abrasive is the key.
Or better yet, don't cook too long.

Terry Caron