Cleaning aluminium help

[stragenmitsuko]

I'm looking for that golden tip to remove oxydation
from aluminium .
Some chemical I can submerge the parts in .

The picture shows the internals of my ac compressor .
The car it came out was damaged in an accident , one of the
hoses broke at the dryer and it was slowly filled with water .

I know I can repair it , I already have a set of o-rings and gaskets
and a new shaft seal .
Just need to find a way to clean it up .

Pat

[Stick Insect]

Hi Pat, there are oxidisation removers available but they tend to be acid based. The best way to clean it is to have the item glass bead blasted. This is the most effective way of doing it. I would suggest being careful about the edges of the casting where it mates on the edge.

wire brushes on an electric drill may help as well.

HTH

David

[stragenmitsuko]

Somebody on a dutch forum pointed me to a very good solution .

Use NaOH ( sodium hydroxid ?? ) to clean the stuff .
You can submerge the parts in it for a few minutes , and
speedup the proces with a tooth brush kind of bristle .

The neutralise the NaOH with salpetric acid . Is that correct English ?

Finally submerge in demineralised water and use the toothbrush again
to form a new oxyde coating and passivate the aluminium .

I've tried it on an old engine mount .
I had to skip the second step because I don't have the product yet .
I just took a soft bristle , paintbrush , and cleaned a part of the engine mount with it . Then rinsed with tap water .

I think the result is quite nice .

Pat

[audiman]

Good luck with the compressor Looks like it may need some serious TLC.

[Stick Insect]

Use NaOH ( sodium hydroxid ?? ) to clean the stuff .
You can submerge the parts in it for a few minutes , and
speedup the proces with a tooth brush kind of bristle .

The neutralise the NaOH with salpetric acid . Is that correct English ?

Finally submerge in demineralised water and use the toothbrush again
to form a new oxyde coating and passivate the aluminium .

Pat

I spoke to a chemical engineer who is into cars and he said.

Sodium Hydroxide ( Alkaline) to clean the parts.
Then neutralise in Nitric Acid ( which is Salt petric acid)
And wash off in tap water. As nitric acid is difficult to find use sulphuric acid as it is easier to come by. Go to your local scrap yard asnt empty a few batteries. They will be glad to let you take it for free ( usually).

HTH

David

[newsh]

There is also a product called Belgom Alu which can be bought in spray bottles from polishing specialists, I've used it in the past and it works well, washes off with water. Dont get it on your skin though :-/ Mind you that applies to any of these methods..

[newsh]

http://www.thepolishingshop.co.uk/Liquid_Polishes.htm

[stragenmitsuko]

Here's the result . Looking good sofar .
I'm quite confident I'll have that ac compressor
running again .

This was cleaned using the method described above , and
brushed with a dremel tool .

You should also see my fingers .
They haven't been that clean in years .
Talk about a peeling .
I should go rob a bank now , not a fingerprint left .
And yes , I did put on gloves most of the time that is .

Pat

[audiman]

Cool, thats come up well. Maybe I can do this to the inlet manifold and rocker cover to clean them up spanking!!

[stragenmitsuko]

You'll still have to polish .
When it comes out of the rinsing water , it looks like
a bit like sand blasted iron .
It's clean allright , but not shiny .

Pat