Scuff area with a cheap engraving tool or dremel. You don't need this, just scratch the area to help the epoxy stick. Engraving tool helps clean up the old epoxy area if a tritium gives up the ghost and you have to replace it. Use a scalpel or sharp blade to remove old ones.
Use very little decent clear epoxy glue applied with a tooth pic to clip. Use clean tooth pick to push Trit down and align Tritium. I get the glue only on backside of Trit not to interfere with Tritium output.
Easy to do and allot easier to replace than cleaning out an old Tritium slot groove covered with the clear expensive stuff (can't remember the name of it.) I have tons of dead tritium in the grooved slots covered with it and a barley used bottle that went bad after opening.
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