Hard Anadized (MIL-A-8625, TYPE III, CLASS 1) in a pneumatic piston application

[Guncici]

I have an aluminum piston that has already been hard anodized (the sleeve only). When I went to go apply pressure the assembly leaked. After doing some research I found that the hard anodize is very porous.

Is there a way I can salvage these piston sleeves? Through polishing & maybe sealing up the pores?

 

[WKTaylor]

guncici

Far too little information provided about this problem to assist.

What piston aluminum alloy? What mechanical finish [ASME B46.1].
What cylinder alloy and finishes [inorganic and mechanical]?
What clearance-tolerances between the piston and cylinder bore?
How much material did You grind to attain clearances?
What seals/gaskets... per what spec?
What is the fluid: Air? Hydraulic Oil?
Etc?
Etc...



Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]