Finishing Suggestion

[ogray]

Can someone recommend the most corrosive resistant finish avaliable? Here's what I've got.

I recently tested a unit that was anodized per MIL-A-8625, type III, Class 2. The unit was tested under MIL-STD-810 salt fog requirement for 30 days and failed miserably.

Can anyone recommend anything?

Thanks.

 

[boo1]

Please provide additional information:
Material, condition, service, temp, desired outcome, cost restraints, quanities....

 

[MadMango]

The application would be nice to know too. "Happy the Hare at morning for she is ignorant to the Hunter's waking thoughts."

 

[GregLocock]

Aluminum in a salt environment is always going to be pretty exciting, since the salt strips the impervious oxide coat away, leaving nice fresh very reactive aluminium exposed.

Paints are the usual solution, and the biggest problem is getting an effective thickness to work on sharp corners, which most paints pull back from. To get around this some people use a powder coat system applied electrostatically.

If you can redesign the part to get rid of sharp corners that is very helpful.

As to which paint or powder system to use, sorry I can't remember any trade names, but we used two part epoxy paints, and I think acrylic is used for aluminium wheels, which suffer the same sort of problem.

Cheers

Greg Locock

 

[SnowCrash]

Sure,
Diamond.

On aluminum you can generate a saphire coating.

(Well he did say "the most corrosive resistant finish avaliable&quot

Crashj 'absolutely' Johnson

 

[MadMango]

I think the two-part epoxy you are refering to may be a zinc-chromate primer. "Happy the Hare at morning for she is ignorant to the Hunter's waking thoughts."

 

[WKTaylor]

Ogray...

If sea-water/corrosive service is a critical aspect, then try alloys that are designed for this environment... and rely less on the corrosion-protective systems.

Regards, Wil Taylor

 

[pmover]

ogray,

wktaylor recommendation best, unless spec requirement is firm. fyi, there are boats throughout Alaska (North Slope) constructed of marine grade aluminum, without external coatings. A thought would be to contact a boat manufacturer as I do not know specific construction materials. -pmover

 

[ogray]

Thanks for the input guys. I just stumbled upon this forum the other day and this is the first chance I've had to use it. It looks like we are going to try a process called Anolube III 15K. Has anyone had any experience with this?