Well, I happen to agree with you on that point... 3M/Scotchbrite used to make an Alumina zirconium (I don't know if they still do) pad which could easily be shaped to form a wire guide/cleaner specifically left untreated for use on Aluminum GMAW wire in order to remove any
"excess" (key word to consider because no wire comes perfectly clean from a vacuum environment) surface contamination that is on the wire before it even reaches the drive rolls and then into the liner which could also be potential locations where the surface of the wire may become contaminated as well...
If you're worried about any residual aluminum oxide contamination from the pads themselves, then use the silicon carbide pads instead, but there's only a very slight possibility that only a very tiny, slight amount of residual aluminum oxide (Brown in color) or silicon carbide (Gray in color) may even re-contaminate the surface once the initial surface contamination is removed... The best, and the cheapest as well as easiest to find non-woven abrasive pads are the Aluminum silicate pads (Green in color) and I recommend these to use as opposed to either the first 2 mentioned previously. ;) So I don't recommend Brown (Aluminum oxide), and would only tolerate Gray (Silicon carbide) if the application is not critical... Green (Alumina silicate) is the way to go if you want to completely eliminate the possibility of even the slightest contamination postweld IMHO. ;)
To use alcohol to "treat" the pad therefore, introducing an agent and, increasing the possibility of residual contamination to occur... This potential for contamination could only occur if the pads were pretreated whereby whichever treatment used would become the method for any residual/scraped off contamination to "stick" on to the surface of the wire once again as it proceeds through the drive rolls and further via the liner/conduit, through the contact tip where once the arc has been established, such a minute amount of aluminum oxide will hopefully become completely vaporized before it ever reaches the weld pool or becomes part of the method of transfer of molten Aluminum filler metal. ;)
However, if you're still skeptical, then use the Alumina Silicate (Green in color) Non-woven hand pads that I previously recommended instead because the moral of the story here is that one must read the ingredients prior to using them in order to "cook" the best possible meal - so to speak! ;) The same applies to welding as well. ;)
Anywho, here are some commercially available products that are specifically for use on Aluminum wire:
http://weldingdirect.com/migwiclpadno.htmlhttp://www.weldmark.com/public/products/pdf/wl-ic42000.pdfhttp://www.fastenal.com/catalog_pages/2009/11-11.pdfRemember to always order the
"Untreated" pads for use with Aluminum wire -CAPECHE??? :) :) :)
And if you really want to save some pennies, then buy the "Green" (Alumina Silicate) Scotchbrite, or Merit non-woven abrasive pads at you local hardware or "wallyworld" store, and then use one of those old style bulk paper clips to hold the pads in place as the wire glides through the custom cut pad/wire cleaner. ;)
Well, that's about it for me for now... So "adios amigo" and I hope this clarifies things a bit and points you towards the right direction as to where you want to go with this. ;)
Respectfully,
Henry