Question:
The front black plug of my TFO sight has fallen out, how do I repair/replace it?
Answer:
You can use a small amount of Loctite® Hysol 11C – black, to seal the forward end of this sight.
http://www.ellsworth.com/henkel-loctite-hysol-11c-epoxi-patch-adhesive-4-oz-kit
This is a two-part epoxy, almost identical to the product we use in house for this purpose. This should resolve any potential problems you might encounter.