Duofold RF
Well-known
Devil is in the details. do it at your own risk, standard claims apply in here.
When I was busy restoring some Leicas I got from USA military surplus many years ago, I gained some personal experience to share with these who dare to try. Canadian balsam was commonly used in 50-60 as adhesive for optical element, due to aging, a hard knock or light knock can separate the prism, the sign of prism separation is blacked out viewfinder, I considered this as emergency/urgent to fix. Due to exposed to air, the coating may oxidized, make it unrepairable, or diminished brightness and contract. Here is how I remove the residual balsam, use a paper towel , tear it into half, roll it into a round brush, in a well ventilated space, dip into acetone, lightly passing through the surface, you may need to do this for several times, be gentle, be patient, to soften and clean the balsam. then use modern UV cured optical adhesive from Edmund optics such as Norland 60 reglue them back. If you have to ask me to give you detailed steps how to take the prism out, this task is not for you, send them to expert as soon as possible.
When I was busy restoring some Leicas I got from USA military surplus many years ago, I gained some personal experience to share with these who dare to try. Canadian balsam was commonly used in 50-60 as adhesive for optical element, due to aging, a hard knock or light knock can separate the prism, the sign of prism separation is blacked out viewfinder, I considered this as emergency/urgent to fix. Due to exposed to air, the coating may oxidized, make it unrepairable, or diminished brightness and contract. Here is how I remove the residual balsam, use a paper towel , tear it into half, roll it into a round brush, in a well ventilated space, dip into acetone, lightly passing through the surface, you may need to do this for several times, be gentle, be patient, to soften and clean the balsam. then use modern UV cured optical adhesive from Edmund optics such as Norland 60 reglue them back. If you have to ask me to give you detailed steps how to take the prism out, this task is not for you, send them to expert as soon as possible.