1001001

1001001

Well Known Member
Has anyone here looked into electropolishing as a method of deburring parts in bulk? What would be the downsides other than cost? Would it affect the pure aluminum cladding on alclad parts negatively? Does electropolishing have a negative impact on strength as anodizing is reported to?

One possible problem I could see is the very high polish would have to be etched to get primer/paint to adhere properly. On the opposing side, it is repprted that electropolishing improves corrosion resistance on the polished surfaces.
 
If you are talking about electroless nickel plating, it is great as long as you do not use it on structural aluminum parts. the nickel is harder than the aluminum and you can get fatigue and wear under the coating, in places you don't want or didn't expect. For other pieces it comes out with a mirror finish and is corrosion resistant. I have used on many parts. You do however, need to polish the aluminum to a mirror finish first (otherwise it will not come out looking like a mirror finish). Good luck.
 
Evolution10 said:
If you are talking about electroless nickel plating, it is great as long as you do not use it on structural aluminum parts. the nickel is harder than the aluminum and you can get fatigue and wear under the coating, in places you don't want or didn't expect. For other pieces it comes out with a mirror finish and is corrosion resistant. I have used on many parts. You do however, need to polish the aluminum to a mirror finish first (otherwise it will not come out looking like a mirror finish). Good luck.
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No, I'm just referring to electropolishing not plating, which adds a dissimilar metal coating to the underlying part. In electropolishing the workpiece is the anode in an electrolytic cell, but unlike anodizing, its primary intent is not to apply an oxide layer, but to cut down high points and edges by removing material electrolytically. The electrolyte used in an electropolishing cell is different than the electrolytes used in anodizing cells.

Electropolishing is used to create extremely smooth surfaces like those required in sanitary piping systems for food and drug processing. It can be done with aluminum and I was wondering if anyone had tried or inquired about doing it to parts like ribs and pre stamped bracket pieces, etc.
 
Just make sure you dont do it too long. It can easily remove a thousandth or two per side if polished too long. The other benefit of ep is removing contaminants imbedded in the surface and replacing the oxide layer leaving super clean smooth surface, with ss anyways. Never heard anyone trying with aluminum.
 
mikedelta137 said:
Just make sure you dont do it too long. It can easily remove a thousandth or two per side if polished too long. The other benefit of ep is removing contaminants imbedded in the surface and replacing the oxide layer leaving super clean smooth surface, with ss anyways. Never heard anyone trying with aluminum.
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Do you know about the timing parameters for aluminum at all? I was thinking of sending some test pieces to a local electropolishing outfit to see the results. It might be interesting to compare what "too long" might be at certain electrolyte concentrations and current densities.
 
Keep in mind, ep is going to remove the same amount of material from all the surfaces of the part. To manually remove the "factory" edge on those punched parts you have to remove at least a few thousandths worth of material, often more, maybe even 0.010 on the thicker parts. I don't think it is viable for edge finishing. There isn't much else to debur other than the drilled holes.
 
I know on machined stainless parts a 3 min treatment removes some of the tooling marks and a 5 min treatment removes all tooling marks . I ep to Astm b912. Not sure if there is a spec for aluminum, I did a quick search and didn't see one.
 
EP

Yes, what a great idea, Having worked in the metal trades for nearly 30 years, we often sent out alum and stainless for ep, the amount of material removed was minute, the question is the integrity of the material for the structure of the plane.
Personally I would call the vendor and ask them if it changes the tensile strength to any degree. If you are to pull off an electropolished plane it would be a beauty!
 
FLightning said:
Yes, what a great idea, Having worked in the metal trades for nearly 30 years, we often sent out alum and stainless for ep, the amount of material removed was minute, the question is the integrity of the material for the structure of the plane.
Personally I would call the vendor and ask them if it changes the tensile strength to any degree. If you are to pull off an electropolished plane it would be a beauty!
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I agree it would be beautiful, however I don't plan on a polished aircraft. Maybe someday but not this -10 I'm building now. I'll call a couple of places and see what they have to say. I am a bit concerned about a previous poster's comment about possibly affecting hole dimensions and part thicknesses too much. My understanding though is that electropolishing only removes the high points until all of them are mostly gone, then the current required to do further metal removal, being proportional to the surface area being removed, becomes the limiting factor, which allows you to observe when the polishing process is mostly complete.
 
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