I have a idea that may work. Look at the anodizing section of this site. http://www.concealcarry.org/ar15/bs-home.htm

Now to get the black color to the allready anodized lower, you put the lower in a dye bath and then heat it to seal it.  On a Colt grey lower, why cant you put the lower in the same dye bath and then seal it.  It is allready anodized, just to light to match with the new black uppers. Technically it aught to work, and still have an origional texture to it. What do you think?

This won't work because only freshly anodized aluminum is capable of taking a proper dye, usually for only a couple of hours after the actual anodizing process takes place.

The anodizing process causes oxygen molecules to bond with the surface layer of aluminum molecules (essentially creating a ceramic layer of aluminum oxide). After this first happens (and also thanks to the heat of the anodizing tank to some extent) the surface is porous and can accept dye. Once the part is finished in the dye tank, it's put into a final tank of very cold water and the porous surfaces close up and forever hold the dye in place. The only proper way to change the color of a dyed anodized part is to strip it (usually in caustic acid) and have the part re-anodized.

That isn't to say dying the part won't work, I just have no experience with it other then to say it won't be the same as a proper dye job done as part of a full-up anodizing procedure...

Walter Birdsong: Black-T

GKoenig
your right.  I didnt think of that.  The lower would allready be sealed.  It would have to be stripped. Damn.  Why does everywhing have to so complicated?  Thanks for your input.

Tech-Plate in CA. Can do the job.. Also PC in Florida does alot of Military refinishing. He will do one piece at a time. Often while you wait.. If you want let me know and Ill post the phone#.( Id do it now but Ive gotta look for it)... John

yes please, the one in FL will be fine.  thanks

PC in Titusville FL. # (312)267-1161

Actually, it is more like a few days, even weeks. The natural oxidization of aluminum is a VERY slow process, but the point is valid...the longer the time between anodization and dyeing the more likely the chance that the color absorption will be uneven.



Although heat is created during the anodization process it is strickly controlled and monitored. The heat of the reaction isn't used to control the creation of a porous surface or the acceptance of dye, although it is taken into account when monitoring the temp of the electrolyte solution. Temperature has to be controlled...too cold (30-50 deg) and the pores are too small to accept a dye..too hot (80+ Deg) and the pores are too large and the dye won't stay in the pores. After anodization, boiling water or nickel acetate is used to seal the pores, not cold water.

It is correct that once anodized, dyed and sealed, it cannot be re-dyed unless the anodization is removed, either by using a caustic stripper, or removing it by a mechanical means such as sanding (although sanding sometimes doesn't work well as much sandpaper uses the same aluminum oxide created during sealing as its abrasive surface).