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3" Shell problems


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#16 karlfoxman

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Posted 21 August 2008 - 05:57 PM

Well Pulverone as I believe it is still granulated BP. Therefore surely small particles of BP.

#17 bigtonyicu

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Posted 21 August 2008 - 06:53 PM

Bigtonyicu IM not trying to be funny (honestly) but I dont understand the last reply re Humidity? are you saying that when you have high humidity your shells show a 20% decrese in height? If so hight humidity is a long step from damp bp and a 20% decrese in performance surely shows that dampness effects the lifting performance dramatically?


With the exception of the water used during manufacturing how else would a lift charge get a higher humidity percentage?

Its the same thing that happens to wood, even kiln dried wood, is around 8% humidity and the amount varies based on atmospheric condition. If his powder was dried from the same batch, and all the shells were made the same way, it would reason that the only source of moisture that could affect the lift would be from humidity that came in at a perforation in or around the cup.


Well Pulverone as I believe it is still granulated BP. Therefore surely small particles of BP.


Pulverstone should be very fine grain,... it's not just the output of the ball mill.

In this case he says he use 4 percent dextrin... so there has to be grains why else would you use dextrin in BP other then to hold grains together?


This post was very dry... sorry I didn't mean for it to sound so mean when I wrote it.

#18 karlfoxman

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Posted 21 August 2008 - 07:10 PM

That wasnt mean, I was just stating that as far as I know pulverone was grains. I wasnt sure what you meant Phil, it is always grains.

#19 Bonny

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Posted 21 August 2008 - 07:20 PM

That wasnt mean, I was just stating that as far as I know pulverone was grains. I wasnt sure what you meant Phil, it is always grains.



I agree with Karl, as to pulverone simply being granulated BP. According to Passfire it is the same as rough powder.

#20 cooperman435

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Posted 21 August 2008 - 10:04 PM

Haha just read back at my post, Think I may have been asleep when I read n posted sorry I was obviously thinking of Pulverone. Sorry.

From my experience bp left unsealed will continue to get damper and damper by simply wicking up the moisture from the air I assume as a hydroscopic effect, what I mean is that a slightly increased humidity can result in much higher absorption of moisture in the bp.

If this isnt the case then my apologies but I know I've had bp stored in unsuitably humid places for short periods of time and had huge differences in performance. I stored 2 identically made shells (actually the same comps split into 2) one in a plastic bag in my drying cupbord and the other in the shed. both fired but whilst the dry stored one was a perfect shell the other was a horrendously low launch which almost made the ground before bursting.

#21 Mumbles

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Posted 25 August 2008 - 04:10 PM

It seems everyone has their own definition for what pulverone means. To me, it is the granulated green meal that I use to fill in gaps in my canister shells. To others it is the milled and granulated product they use to lift or break shells. I wouldn't be so quick to assume he is using some sort of meal product.



edit: I didn't see the second page where this is discussed.

Edited by Mumbles, 25 August 2008 - 04:13 PM.


#22 Pretty green flames

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Posted 25 August 2008 - 05:52 PM

To me, Pu(o)lverone is granulated meal powder, and rough powder is granulated green mix that I use for filling the speace inbetween cut stars in canisters. So Pulverone and Rough powder, in my opinion, are not the same. Can get confusing sometimes so It's mostly called BP :lol:

#23 Bonny

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Posted 25 August 2008 - 06:09 PM

To me, Pu(o)lverone is granulated meal powder, and rough powder is granulated green mix that I use for filling the speace inbetween cut stars in canisters. So Pulverone and Rough powder, in my opinion, are not the same. Can get confusing sometimes so It's mostly called BP :lol:



In the Passsfire "Rough Powder" tutorial, although it says it is also called Pulverone, it does have some differences depending on usage. If only being used as a filler it says to use greenmix. However, if using as lift and/or burst, Maltese style, then it recommends milled powder be used.
Anyway, for use as lift I think ball milled powder is a must, regardless of which technique is used for further processing, be it granulating or perssing and corning.

#24 ridley

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Posted 26 August 2008 - 01:41 PM

The pulverone I have used is made from fast milled BP with 4-5% dextrin, wetted with water/alcohol and pushed/grated through a screen.

I have taken a picture of the life cup and it seems to have melted through the side of the lift cup as well as burst out of the top/side, so to me it looks like it must have been slow. What do you think?

http://www.flickr.co...N07/2799191041/


Ridley

#25 Mortartube

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Posted 26 August 2008 - 03:11 PM

Far too slow if it did that to the lift cup. IMHO
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