Wild-goose-chase: 17x20x1 mm glass - Red Safety Filter

[zsas]

Poly- good points. This is an intra head filter (Leitz V35). I measured the temp of the light path where the red filter would go and it was 200F (per an old meat thermometer). I don't think (could be wrong) Rubylith is safe in a 200F+ enlarger head. I searched Roscolux and the red Rosco can go to 220F...that seems too close for me (ie fire hazard). I presume Rubylith isn't heat resistant (googling did find my answer in 3 mins so I quit lookin...).

Note that Pebeo glass paint is baked onto the glass at 325F for 40mins. That's why I knew I could get it near my enlarger head.

In the meantime of all this, I bought an extension tube for my enlarger that allows a longer lens to be mounted, now I have a much more comfortable working space and don't mind the under lens holder. Think I'm ready to call uncle on this project and appreciate the help. Now if Rubylith can go to 250F+....well you will for sure be the MacGyver challenge winner......

 

[polyglot]

When you say you tested with a meat thermometer, my guess is that the thermometer was mostly radiatively heated by being in the light path. The filter may be less heated maybe. The rubylith I have is plastic of some sort, but 200F isn't *that* hot... Don't blame me if you burn it down though

Anyway, rubylith is real thin. You could stick it right under the lens or slap a large sheet of it directly on your print?

 

[richard ide]

One thing to be careful about with Rubylith is age and possibly also heat. Rubylith is a red lacquer layer on a clear polyester carrier film. This layer can be cut and areas removed (graphic arts and photo applications). With time the red coating gets brittle and may crack unless handled carefully.

 

[smieglitz]

What about sandwiching a piece cut from a #29 deep red Wratten gelatin filter between two microscope slides that have been cemented/taped together? Someone must make a tape that can withstand the heat and if the filter is between glass how would it burn? Might melt but with no O2, would it be possible for it to burn?

Didn't Cibachrome filter sets include a red? What about a filter from one of those color correction viewing kits? Or, wait for it... a piece from a red welding curtain?

 

[zsas]

Think I quit the project, the V35 enlarger with a 63mm lens, extension tube, under lens filter - now yields 6 inches of "leg room" - tis enough for me to end this hunt for a unicorn red filter. Messing with a glass red filter, sandwiching or whatnot will not matter anymore considering I've the room I need -(pix shows ruler ontop of easel frame - 6 inches to work with ):