Importance of Charcoal Selection in KP Burst

[AirCowPeacock]

How important is the grade of charcoal in KP burst? Is it as significant as in BP? I'm planning on switching to KP in my small (less than 3") shells, but am running out of good buckthorn charcoal. If possible I would love to wait til early spring to make more, to avoid spending to much time outside and processing frozen, ice covered wood. I do however have alot of skylighter charcoal, which I use for stars and prime.

[Mumbles]

Charcoal is important. In my experience, it's important in the opposite way that it is for BP. Too hot of a charcoal will turn your shells into salutes. I was making larger shells though, so it might be fine for smaller shells. I've made it with standard airfloat charcoal, and it worked fine. My preferred charcoal was always ground up Cowboy brand lump charcoal. For me, it's somewhat hotter than airfloat, but still toward the lower end up acceptable for BP. If you cherry pick the softest pieces from the bag it works for lift, but using everything gives something that isn't all that impressive. If you want to conserve your hot charcoal, a mix of hot and airfloat should work. I'd start around 5 parts hot and 13 parts commercial airfloat.

 

I have a burst I use now that is a mix of potassium perchlorate(70), potassium benzoate(15) and charcoal(11) that is definitely designed to be used with commercial airfloat. Using willow even blew 3" shells with spider stars blind.

[pyrojig]

In reading Hardt's book, it claims the charcoal is not very relevant as opposed to bp's need for hotter charcoal. This goes for both kp and h3. Some have used activated charcoal to try and absorb more oxidizer.This of course would be pathetic for bp. In my testing, i tried to keep as close to Shimizu's original mix , and use paulownia (subbed for hemp).,

[AdmiralDonSnider]

A lot will depend on how fine your charcoal is. Using ballmilled material as opposed to screened -200 mesh will make a difference. My limited experience tells me that paulownia (hot charcoals) work well without any ball milling.

KP is contingent on pressure and the results can be modified by altering the pasting thickness.

Shells much smaller than 3" will require you to use granulated KP without carrier materials. Here the granule size will make a huge difference. H3 is probably better for such small shells.

[AirCowPeacock]

I'm sure H3 is better for very small shells, but I lack chlorate and would love to not even have to think about sulfur in my stars, especially because I love my charcoal streemers and thunder #3 salute inserts and bottomshots.