A common temp. for bluing solution is 265-285 degrees F. A common solder for ribs on doubles is 50/50, although 60/40 may also be found. The melting point for these solders is higher than 285 degrees. If temperature were the problem, you also couldn't blue rifles that have soldered on sight bases, sling swivels, etc. in caustic solutions. For accuracy sake, some new double and drilling barrels are blued in caustic solution; but only for a short time( less than 14 min.)specifically to remove solder residue that is difficult to see in the polishing process.
Mike

Last edited by Der Ami; 07/20/17 11:08 AM.