Jeremy Gremillion and Ray Ramagos both make their catfishing bottles from emptied, metal, 30-pound R-22 refrigerant bottles. Gremillion gets his from friends who do residential cooling work. Ramagos noted that they can also be purchased from scrap yard dealers.
1) Using a hammer and punch, pierce the bottom of the bottle to make sure that no pressure is trapped in it. Then, using either the punch or an acetylene torch, make three additional holes in the bottom. These holes are to allow water to drain from the bottle when it’s being raised.
2) Turn the bottle upright and cut an oval hole on its upper shoulder with an acetylene torch. Gremillion prefers his hole to have a 3-inch vertical opening and a 5-inch horizontal opening.
The size of the hole determines the size of the fish that will use it. “I don’t like bigger holes because they catch bigger fish, and I like the taste of smaller fish better,” he explained.
3) Tie a small rope or heavy cord suitable for the water depth to both of the handles so the bottle comes straight up when it is being retrieved. Alternatively, the cord may be tied to the bottle’s small central valve.
Tie your float of choice to the other end of the line. Gremillion uses floats cut from swimming pool noodles, but cautions that the floats must be changed every year so they don’t deteriorate. “A lost float is a lost bottle.”