caustic lye and alloy (last time I ask this, I swear)
 

I just want to know if the caustic lye (NaOH) will mess up my choice cro-mo steel frame when I put it in there to dissolve the aluminum seat post that is royally stuck inside her. Buddy says alloy is different than elemental metal but a jar of draino, which contains NaOH says to keep away from chrome, and as we know there is a fair bit of chrome in that steel frame. But is she locked away chemically inside that iron, or will she be lured by the temptuous and exciting sodium hydroxide, corrupting the structure of my beloved Japanese Lugged Mountain Frame? Any inorganic chemists in the house? Please share. Many thanks, and sorry for bringing this up again but the search engine isn't even giving me a straight answer (people who had gone the way of Lye did so on high-tensile frames which of course contain no cromium).

The NaOH won't hurt the steel (Cr-Mo notwithstanding, the warning is about chrome plated parts.) and it will dissolve the aluminum.

BTW. one of the byproducts of the reaction between Al and NaOH is gaseous hydrogen so do this outside!

I assume you are aware of the hazards of handling NaOH and will take proper personal precautions.

yeah definitely, H2 gas, that's the best part! it's gonna be awesome