How do I apply a strain relief on the electric match wire?
All methods of wire strain relief have the primary goal of keeping the wire which is hooked into a cue from being pulled violently away during firing of the shell. If the wire is pulled away (since it is attached to the shell) at high speeds, it has the potential of prematurely pulling out adjacent cues, rendering them un-fired. A good strain relief will allow the wire to break on the shell end instead of being pulled out of the cue. There are quite a few methods for strain relieving a wire, however, I will discuss the two best in my opinion. Namely,
Quick Release Method - The quick release method strain relieves the wire, at the same time allowing for an extremely simple removal of the wire from the mortar at the end of the night. You are literally tying a slip knot. The knot will not give when the wire is being tugged on during firing, but when pulled from the other end, it comes out with no effort at all. This method requires a small hole just big enough for the wire to fit through at the top of the mortar. Watch a video explanation of how to strain relief a wire on a fireworks mortar (same video as above).
- Quick Release Method
- Half Hitch Method
Half Hitch Method - This method is used when there is no hole available at the top of the mortar. It is not as reliable as the Quick release method, however still very effective when done properly. This method consists of creating a "half-hitch" with the wire, and placing this over the mortar. See picture to the right.
An additional backup technique is to pass the electric match wire between the mortar and the rack it is placed in on the way to the slave module your going to plug it into. This is of course after it has been strain relieved by one of the above techniques. See quick release picture to the right.
Do I have to remove the plastic bag that some individual aerial shells come in?
No. This is really up to you, as it does not effect the performance of the shell. The heat created by the lift charge literally makes the bag disappear during firing. Just load the shell with the bag still around it. This eliminates the amount of trash you generate at a show.
The shell barely fits, will it come out when fired?
Yep. The general rule of thumb is that if you can get the shell to the bottom of the mortar, it will come back out. Mortars, especially those made of HDPE tend to warp over time. This is ok as long as the shell can still be loaded to the bottom. It's ok if the shell is a little tight, as this should not effect it's performance. In actuality, it will increase the height the shell reaches. Now, if you have to cram the shell down by hammering it in with a stick (don't do that), that's no good. The shell must be able to slide freely down the gun with a minimal amount of assistance. In most cases, the shell slides down the gun under it's own weight.
Aside from the danger factor, keep in mind that most shells utilize cardboard for their casing. This cardboard must be able to hold up during the violent process of firing. This is most likely not the case if the shell has to really force it's way out of the mortar, especially if you have potentially damaged it by ramming it down there in the first place.
If it's raining, can I fire through plastic sheeting?
Yes! You may worry that during a good storm when you have all your guns covered with plastic sheeting that this will impede the performance of your shells. Yes, but in a negligible way. Your shells will blow right through the plastic as if it wasn't there, especially if it is tightly secured over your guns. Ultimately, if it isn't raining, remove the plastic before you fire. But, if it is raining hard or you expect it to during the show, know that it is ok to leave it on in these circumstances.