This is hands down the best recipe for making paint grenades that will obliterate an entire room or 15ft radius when thrown and are 100% reusable (if you are able to retrace your steps to find the cap and tubing). Either way, despite initial start up costs, they are still more economical than buying the same quantity of Tippmann Big Boy grenades (which these are modeled after).

Materials:

1" diameter PVC pipe cut to 3/4 inch lengths

1/8" x 1-1/2" cotter pins

1-1/4" key rings

Black Heavy Gauge Surgical Tubing 5/8" OD x 3/8" ID x 1/8" wall (cut to 6 inch lengths)

Hog Rings (zip ties may be substituted but not as ideal)

Paint Mix (3 part water 1 part washable non-toxic paint from Walmart)

Scrap piece of copper or other metal pipe approx 3/8 in diameter.

Tools:

Forceps/Hemostats

Curved Needle Nose Pliers

Hog Ring Pliers (if you go this route necessary)

Blow torch

Fill Station (see my other Instructable if you don't have your own method of filling)

Step 1: Cut and Mark Tubing

Setup:

Mark on a table top 4 lines with a sharpie. Farthest left and right lines are 6 inches apart and I marked with a black sharpie. The middle two are 3-1/4 inches and 5-1/4 inches from the left most mark. These were marked with a silver sharpie for later.

Lay tubing out and use this scale to cut repeated 6 inch lengths.

Once you have all of your cut tubing done, go back with a silver sharpie and lay the tubing back where you cut it between the two outer most lines. Use the silver sharpie to mark on the black tubing the two other middle line marks (one will be where we cut a hole, the other will be where we hold the PVC cap while filling). Once marked, the left side of the tubing will be the bottom of the grenade and the right will be to top/nozzle where the paint will spray out from. The silver mark on the right will be where we make the hole to spin/spew paint.

Step 2: Cut PVC and Make Pull Rings/pins

1. Cut PVC pipe to 3/4 inches on miter saw or with hand saw/what have you. Painting is optional but will look more authentic. If you are going to paint them, it is best to sand the whole piece of pipe before cutting so paint will stick and you won't have to sand all of the individual pieces after you cut.

2. Slip cotter pins onto key rings to make pull pins.

Step 3: Cut Nozzle Hole and Crimp Tubing Ends.

Using 3/8 diameter piece of copper pipe and a lighter or blowtorch, heat up pipe and press thru tubing with pipe just touching mark line closest to the top end of grenade tube. Slip a skinny piece of wood or other material into tubing so you don't go all the way thru the other side of the tubing.

Step 4: Crimp Ends With Hog Ties

Crimp both ends of the tubing. Hog rings are pictured being used and will hold better than zip ties. They allow you to get closer to the end of the tubing without it sliding out. Zipties tend to slip and require a little extra tubing to stick past them in order to hold fast. See photos for orientation of crimping.

Step 5: Start Filling

See video for walkthru. Much easier than typing it all out.

Grenade filling video:

Step 6: Testing

Grenade Test Video:

This video was the second one I shot because I had a bad throw the first time. To get the best results, you need to have the grenade bounce up into the air one way or another. If you throw it against a wall it will begin spinning but get interrupted by the second impact when it hits the ground a second or two later. It will still throw out decent coverage. But for best results it should be thrown up high so when it comes down, it bounces back up allowing it to spin and empty all of it's paint while in mid air. I use these mainly for room clearing in paintball games.

For example, you and an enemy are in adjacent rooms in a building. Neither of you wanting to go through the door first so it turns into a stalemate where you both just sit tight watching the door for the other. That's where these grenades have been crazy effective. If you have a teammate with you, have them cover the door so you can lower your gun and pull out a grenade. Press down on the PVC cap and pull the pin out. Then throw grenade around the corner at a downward angle (imagine an NFL player spiking the football after a touchdown) into the room. This will cause the grenade to bounce back up high enough to dump all of the paint 360 degrees into the room and take out anyone in there.

Another example is to lob it high so it comes down behind a bunker in the woods and bounces that way as well. If you throw it like a baseball it will be less effective when it bounces off a wall or tree and gets interrupted by the secondary impact while it's still trying to spin.

Message me if you have any questions.