Author Topic: Products for removing salt corrosion from aluminium engine block. (Read 1103 times)

Gunnytron · « **on:** August 21, 2024, 02:34:57 PM »

I have a car that has a tatty looking engine block due to salt corrosion (gritted roads). Has anyone heard of a paint/spray-on product that can make the aluminium bright and shiny again?

I have watched a few vids, but most of them appear to leave a dull finish, or dont remove the darker stain/corrosion.

I have thought about dry ice blasting but access is limited and I am not sure how effective it is salt corrosion.

FYI the engine will be in the car.

digitalsolo · « **Reply #1 on:** August 21, 2024, 02:58:28 PM »

The -most- effective is probably vapor blasting, but I don't think you could do that in situ. Dry ice will probably be next.

I've used "Aluminum Brightener" which is an acid product and NASTY, but does clean things up pretty well.

Gunnytron · « **Reply #2 on:** August 21, 2024, 03:35:15 PM »

Vapour blasting does look good. I might have to make do with the brightener though. Thanks.

kinger · « **Reply #3 on:** August 21, 2024, 04:30:37 PM »

What part looks bad? Are you just trying to see the end of the heads or the actual block that is really hard to see? I haven't found a dang thing except a silver aluminum paint, but that isn't long lasting either. I have submitted to leave it as is or if you clean it you must seal it. On the bright side it looks better then steel rust

Esser · « **Reply #4 on:** August 22, 2024, 09:22:30 AM »

Purple Power

digitalsolo · « **Reply #5 on:** August 22, 2024, 09:41:50 AM »

I will add, a brass bristle brush helps a lot in removing the corrosion. I cleaned up the suspension (aluminum) on my Aston with Simple Green and a brass brush and it made a HUGE difference. I wasn't going for "shiny" just "clean" but it was pretty nasty to start with, as suspension with ~60k miles on it tends to be.

Exidous · « **Reply #6 on:** August 22, 2024, 10:52:47 PM »

Any alkaline degreaser will generally work. Just don't leave it on the aluminum for long. It will "melt" it.

Purple power or similar are good. It just needs to be sodium hydroxide based.

Cobranut · « **Reply #7 on:** August 23, 2024, 01:10:43 AM »

I second the Purple Power or the Acid Brightener.

Once it's clean, I found that POR-15 Glisten PC 2-part urethane is an amazing clear paint to seal it up.
I did all the aluminum on the Ford 427 in my Cobra when I built it back in 1998-99, and it still looks like new.
The only discoloration at all is on the heads right at the exhaust ports. It didn't peel or blister, but did darken a bit to a transparent brown. Gasoline doesn't affect it, and it has a slick surface that wipes clean easily.

Gunnytron · « **Reply #8 on:** August 23, 2024, 03:07:16 AM »

Cool thanks everyone. I see if can get purple.powrr or similar over here.

shainiac · « **Reply #9 on:** August 23, 2024, 02:45:50 PM »

I've had good luck with Nucalgon foaming condenser cleaner. It's basically 25% sodium hydroxide, 5X the strength of Draino.
It's serious stuff. You definitely don't want to get it on your skin and you definitely do want to rinse and neutralize it after.
I've had one instance where it discolored aluminum, on the rear cover for an aluminum 8.8" IRS. For whatever the alloy wasn't happy with the cleaner and turned grey-ish.

Before: