Lapping Aluminium

[kenre]

What is the best way and compound to lap a 30% Si Aluminium alloy?

Used for pistons running in tapered hard chrome bore.

Yes the piston has some 'pinch' towards the top. This is a must have.

I have lapped the bore with Diamond paste on an internal lap with exellent results.

Ken

 

[ImanCarrot]

That is about the best way to do it, using Engis or Hyprez Diamond Paste.

Alternatively, you could ave it machined by Single Point Diamond Turning which will give an optical polish with extremely tight tolerances and physicaly stronger

 

[kenre]

Thanks Imancarrot.

The diamond paste cannot be used on the aluminium as it will become embedded never to be removed. Do you know of any compounds specifically for aluminium?

Ken

 

[unclesyd]

We used a non-embedding Garnet abrasive with a Helical Lap and polished out with Simichrome Polish on Aluminum parts. The Simichrome Polish has a 3-6 micron abrasive.

We may have bought the Garnet abrasive from the Helical Lap Co.

http://www.helicallap.com/index.html

You can get the Simichrome Polish at most good hardware stores.

http://www.marbeck.com/cleaners_household_simichrome.html

 

[kenre]

Thankyou unclesyd!!

Exactly what i need to know!

Ken