Mines, the Ultimate Ground Effect

I am partial to fireworks mines because they allow the viewing audience to be a little closer to the burning stars. This is true because a mine is a ground effect and ground effects, in general, are more predictable and controllable than aerial effects. Mines are also simpler to make because there is no need to contrive a delay mechanism or a reliable burst charge to achieve a desired pattern in the sky. There are many ways to make mines for different kinds of results, but the approach described here is about the simplest I've seen and produces a pleasing, bushy column of burning stars. The technique is used for making mines for a 3 inch mortar, but the principles should apply to mines of many sizes.


The first task is to scrounge around for a former that is the right size. Here is a picture of a water bottle that is about 1/4 inch smaller in diameter than the mortar used to fire the finished mine.
A common, ordinary brown paper bag, such as a lunch bag, is folded neatly around the former or sloppily scrunched around it, depending on the artisan's personal style. A few wraps of packing tape will assure that the original shape of the former will be retained by the bag upon removal of the former. Now, you could painstakingly construct a cylindrical mine bag by custom cutting a piece of craft paper to roll around the former, but either approach will produce a result which is pretty much functionally equivalent. I'll take the quick and easy way any time. If a lunch sack is used to make the mine bag, the top 4 inches will need to be trimmed off after removal from the water bottle former.
Next, we need a leader fuse that is long enough to protrude from the mortar by about 12 inches. My mine mortars are 20 inches tall so I make a leader that is about 3 feet long. For single shot mine mortars, a length of home-made sticky match will do nicely. The picture shows a length of match with a piece of visco at one end and a piece of thermalite igniter at the other end. The visco end is obviously where ignition fire is applied and allows the prudent person some time to retire to a safe distance before fire is passed to the fast burning sticky match. The other end with the ignitercord or black match is expected to hold the ignition fire in the vicinity of the stars for a long enough time to ignite them. The flash flame of sticky match alone might not reliably ignite the stars in the mine. A note of caution is in order at this point. If you are planning to load a lot of these mines into a rack of mortars, the sticky match leader fuse is not the best idea. In this case, one should use a leader of quick match because it is much less vulnerable to accidental ignition from sparks from a nearby mortar which has fired its contents skyward.
To make a simple star bag, a small cup is used as a former. A 10 inch square piece of tissue paper is stuffed into the cup as shown. The thermalite end of the sticky match is placed in the cup and 100 grams of your favorite stars are added. It's a good idea to bend the piece of thermalite into an "L" so it won't poke a hole in the bottom of the star bag.
Now the edges of the tissue paper are drawn up around the fuse and secured with a wrap of tape. The tape should keep the fuse from being pulled out of the star bag.
Finally, approximately 24 grams of good quality lift powder is placed in the bottom of the mine bag. I use home-manufactured black powder that has been corned into 4 to 10 mesh grains as an equivalent to 2FA commercial powder. Depending upon the quality of your lift powder, the amount used may need to be adjusted. The star bag assembly is placed into the mine bag on top of the lift powder. The concept, here, is that this method of assembly encourages good star ignition because the stars begin to burn for a short time before the lift powder is ignited by them and ejects them from the mortar. The final step is to close the top end of the bag with some manner of folding and taping. The fastidious craftsman will want to make a few pleats and tape it closed neatly. The less fussy person may just scrunch the top around the fuse and put a wrap of tape around it. To each his own.
If you plan to make a lot of different kinds of mines with various kinds of stars in them, you will be well advised to use a marker to label your mines. It's a little embarrassing to announce to your audience that the next mine will be a glitter mine with red strobes for accent and upon lighting it, the mine turns out to be blue to green color changers. These 3 inch mines will put up a large column of stars to a height of about 80 feet.

Your feedback is welcome. Please offer suggestions, refinements, critiques or cudos in the submission form below. You must be a registered pyro enthusiast (or at least a wannabe) to contribute.