Murakami Hardeners for WB and Discharge,
If you use one of our SBQ emulsions, Aquasol HV, HVP, Photocure BLU, TXR the first step would be to add 8g diazo per gallon to increase water resistancy in a pure photopolymer emulsion.
Then you can use MS-Hardener which allows the screen to be reclaimed. Apply with a wet cloth or a paint roller dipped in hardener. Dry in sun (for heat) or put in a screen drying cabinet at 100 degrees. Heat helps the hardener do it's job.
If you want near permanent screens you can use A&B Hardeners. Mix only what you will use in a 24 hour period with equal amounts of A&B. Good for long runs and multi color discharge prints. Reclaiming is not impossible just difficult. You need to etch the surface with a caustic haze remover, HR-700 from us. Leave on for 5 minutes then apply emulsions remover, or better use a concentrated dip tank of emulsion remover. ER-605 7.5:1 mix.
For Dual Cures and Diazo based emulsions like SP-1400, SP-7500, Photocure PRO you can harden with MS Hardener for reclaiming, or A&B Hardener for stronger screens.
One note worth mentioning is the stencil strength is determined more by how well you expose it with good strong multi spectral light. Hardeners assist strength, but shouldn't be looked at as the answer to making a good wb or discharge screen. A screen shot on an 8k Douthitt will be far stronger than one shot on fluo tubes. I may not even need to harden the screen on a 2,000-5,000 piece order with HVP if I have exposed it with quality light for the maximum amount of light possible. Murakami emulsion is designed to be exposed completely and still develop details with a pressure washer. Many shops have bad habits of under exposing a screen to get details due to emulsions that have to be underexposed to get details. Applying hardener to an under exposed screen is just applying a band aid to a screen that has incomplete exposure. The hardener affects the surface, not the entire thickness of the emulsion, only good exposure practices create cross linking that leads to a strong screen. Pure Photopolymers do gain some strength in post exposure, but never as much strength as they can achieve with: A well dried screen, complete exposure, MS or A&B Hardeners, Post expose in sun/exposure unit then dry in screen drying cabinet/room at 100 degrees will achieve an incredibly strong screen.
