We no longer remove the secondary from the aluminum back plate during re-coating unless there is some unusual reason for doing so.
If a mirror is attached to a metal back plate the adhesive can be softened by soaking overnight in regular paint thinner. Then slip the edge of a utility knife blade between mirror and back plate to gently separate them. If using 'Silicone I' you can probably cut the sealant without soaking. Or otherwise slip the blade of a hacksaw between mirror and wood back plate to saw the sealant. Keep metal tools away from the mirror face.
When gluing mirrors to their mirror cell be sure to allow the sealant to cure overnight.
September 8, 2006
