I am building a rocket rack for some stick rockets (Lite Em Ups and Pound Rockets). Planned on using 2 x 4's and PVC pipes mainly, but was wondering how far apart I should space each pvc pipe so it doesn't ignite the rocket next to it, or should I just cover the fuse with electrical tape and then I could space closer. Trying to get in as many as possible. Would like to have at least 50 tubes. Thanks for any advice.