LEDs in glass rocks

[zenith]

After my successful initial foray into the world of electronics and LEDs, thanks to the help and advice of the folks on this forum, I have finished quite a few projects, including converting my 2 workshops to LED lighting.
My current project is outdoor lighting, several years ago I was given a lot of glass rocks, which have lived around the garden, I'm about to drill these from the underside and fit some RGB slow change LEDs into them.

Now I already have them wired up and ready to fit, but I was wondering on the best way to seal the holes after the LEDs and wiring is inserted.

I have a lot of hot glue sticks or I can buy some silicon, which would be better ? or is there another way?

 

[john monks]

I typically use clear epoxy to glue LED's in place.
You don't want to use any translucent or colored glue because it absorbs light and you want to seal the water and bugs out.

 

[shrtrnd]

If you ever plan to change LEDs, I'd use the clear silicon. It's pretty tough and is pretty easy to remove.
john monks idea will work fine also.
(but if you ever have to remove it, you might end-up chipping-away at your stone)

 

[zenith]

Thank you both, I have decided on the silicone, since I may need to remove them at some point.

 

[alfa88]

A word of caution on selecting silicon. Alot of readily available formulations use acidic acid and will eat up the copper leads. Use a formulation that's safe for aquariums.