It rains a lot where I live, but I don't want that to hinder my marker choice. To waterproof the front grip is actually quite easy, just wrapping it in tape works fine. I only put one strip at the top of the grip where it meets the body, just so no water can get in that way. I don't have to remove the battery cover to change modes with my virtue board, but if I wrap tape around the LED display I won't be able to see what modes I'm in. I decided to make a simple window for the LED so I can still see the display, but waterproof it at the same time. I haven't seen anyone else do this on the forum, so forgive me if this has already been posted.
I removed the fore grip from the gun first. Then I remove the board from the fore grip. Then I cut a little square out of thin clear plastic, make sure it's stiff but still thin. Cut a piece of clear packing tape the same thickness as the back of the fore grip where the LED window is. Place the square piece of plastic on the inside of the window, then place the tape over top of it, pressing with your fingers around the tape, sealing it around the plastic window.
Put the board back in, and you're good to go! A super easy fix to seal up the LED display from water/dirt, while still perfectly displaying the LED