aluminium corrosion product
aluminium corrosion product
(OP)
is there a liquid "solvent" which removes the white/yellow corrosion product from aluminium ? I am thinking of marine grade cast aluminium which has corroded in sea water..obviously the fluid cannot also eat out the aluminium casting in the process...Old sea dog





RE: aluminium corrosion product
RE: aluminium corrosion product
http://www.eaa72.org/tech/ac43.13-1b/2m-ch6_8.pdf
RE: aluminium corrosion product
I recall that we tried to remove aluminum oxide in our processing once and wound up using an ion mill to literally blast the oxide off, since it resisted all of our chemical etchants.
The MIL-C-38334 compound is relatively mild, so you'll probably need to wire-brush or grind off the majority of the corrosion, treat it with MIL-C-38334 compound and then anodize the surface to prevent or minimize future corrosion
TTFN
RE: aluminium corrosion product
If you have to use an H3PO4 based material the best would be from a chemical supply store. I would try one made for Al fins first. Get the concentrated variety, this will allow you to use higher concentrations if the white rust is heavy
http://www.eastwoodco.com/shopping/search/searchresultsmain.jsp?fresh=1&searchType=advanced&iMainCat=0&iSubCat=0&attribute14=0&attribute15=0&attribute16=0&RS=1&keyword=semichrome
Come back with whether it’s pitted or not.
RE: aluminium corrosion product
RE: aluminium corrosion product
The next best method is to use a commercial deoxidizer/desmutting solution. These are either nitric or sulfuric acid based, but contain inhibitors to stop the attack when bare Al is reached.
Concentrated nitric acid (67-70 wt%) is also very safe for cleaning Al (pretty harmful to humans, though). A protective nitrate forms once the bare Al is reached. http://www.pc.chemie.uni-siegen.de/pci/versuche/english/v44-24-2.html
Dilutions to 50 vol% (38 wt%) are commonly used to reduce the nitric acid fumes, but the reactivity vs. Al goes up fast if the water content is increased. Useful for stripping metallic plating, too, e.g., EN (electroless nickel).
If possible, take your part to a nearby anodizing or plating shop, as they already have the above solutions and can safely handle.
RE: aluminium corrosion product
Excellent point about using conc. HNO3. That's what I used way back in my first met. lab. job, in 1960 to clean small pieces of alum.
RE: aluminium corrosion product