Rustman

How does one dull aluminum that has been polished? I'm grinding down some welded cracks in an intake and in the process, the area has become slightly polished.

Does anyone think Eagle One Etching mag cleaner will dull the polished area back to original, or do I have to use something like muratic acid (diluted or full strength)? This is not a fullblown restoration, just want it to somewhat match.

claysmoker

It depends on how much you want to knock it down. I'd start slow and work my way up as it's tough to back up if you kill it too much.

Try a stiff toothbrush and scouring powder/water mixed into a paste. That will dull it slightly. If you want to go really aggressive, mix a little Drano with water and brush it on, but be prepared to rinse immediately so it does not get out of control.

Good Luck!

MiguelsC2

Just spray the acid on for a while and rinse. If you want to localize, use a q-tip.

You can use a little steel wool to even it and bring it up to the level you want.

6T7L71CPE

Old fashioned oven cleaner will do it too.

3JsVette

If the manifold has a rough or textured finish while chemicals will dull it you have to bead blast it to get a uniform finish. It just depends on how "perfect" you want it to look.

jim lockwood

I've tried oven cleaner. My observation was that it noticeably darkened aluminum and pot metal. Probably best to test in an inconspicuous location before committing to this chemical.

Jim

Edit: More accurately, I've tried the active chemical that's typically found in oven cleaner. It's available in hardware stores.

Rustman

Thanks guys for all of the advice.

66jack

try and find a old beat up one or similar to test on first

devildog

This manifold has a crack welded and all four flange edges had 3/8 inch of aluminum weld added to cover larger head ports. You can not distinguish the added metal.

Shaped the weld deposit then lightly hit with small grain sandblaster.



The flange areas were shine until kissed them with sand blaster.

Joe