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Greenville Pyro
09-01-2021, 12:46 PM
Just out of curiosity, has anyone MJG'd a fountain? I can only assume it is a similar process to poking a cake, except at the top?

WithReport
09-01-2021, 01:37 PM
No it is not the same. A fountain is much like a solid rocket. You don't want to poke a hole through the side!

It is best to use the MJG to light the fuse going through the nozzle. You can shorten the fuse or use a faster fuse.

There are various approaches on using MJG to directly light a fuse and MJG has their visco initiator, too.

Greenville Pyro
09-01-2021, 06:07 PM
I may not have been clear enough. Yeah, definitely not poking through the side! I meant poking on top next to where the fuse enters. Or, I could replace all with grey fuse as another option.

WithReport
09-01-2021, 06:26 PM
If you get down to the actual fountain tube you will see a nozzle at the top. You don't want to damage or poke through the nozzle.

The visco fuse is usually just pressed into the nozzle and into any core of the fountain, sometimes I've seen glue or a BP slurry in the hole, too. You could remove the fuse and replace it with a faster/different fuse. Typically the fuse is bent back on itself when inserted into the fountain through the nozzle - at least per the courses I've taken and literature I've read.

You could try opening up the nozzle to insert a match and shroud. I would use a drill bit and slowly open up the diameter of the nozzle until the shroud fits, but this will effect the performance of the fountain.

Since you are using MJG, it it is scripted, you could just account for the fuse delay time in the script. Also sometimes fountains have just a starting fuel at the top of the tubes just to get things going, so the actual fountain performance, may still have some delay.

http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=5987&stc=1

displayfireworks1
09-01-2021, 08:23 PM
In the past I would sprinkle some black powder into the open part of the fountain , place and electric match head directly on top of it and Magic Tape over top of it all. It seems to get them going almost immediately as the match goes off. Same with Roman Candles.

Greenville Pyro
09-02-2021, 03:24 AM
Thanks guys. Those last 2 posts were exactly what I needed to know