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burst charge


eb11

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is there a certain amount that should be used for a burst charge if so what is the amount per each shell
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That?s all depends upon size of shell and type of burst charge you are going to use.....small shells less than 4 or 3 inch requires strong burst....

The following bursting charge amounts are suggestions only; experimentation through trial and error with various burst charges and the amount used is the best way to decide what is right to use.......also you would have to think about carrier/burst composition ratio....

For example......

Bursting charge amounts for chrysanthemum shells

3''/4''/5''/6''/8''/10''/12''(size of shell)

40/56/70/140/395/950/1250(burst charge amount in grams)

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Just fill slightly above the top of the hemi when building, amount doesn't really matter, what does is type of burst like Swap said.

The litle extra should compress a litle and lock the stars into place, so the don't ramble or displace.

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i am doing 2 inch shell and using bp as burst it is not bursting all that well so i am thinking i need to go to fp but am not sure of an amount to start off with
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Replace bp burst with strong burst charge like KP burst......If you want to continue with FP then start with nitrate based slow flash powder.

make slow flash coated rice hull and meal coated rice hull separately and mix them in a approx ratio of 3 :1, adjust the burst by varying the ratio to get optimum result as all the coated hulls may not have the same strength.

BP+slow flash powder (booster) is another option. For 2'' shell 3 to 4 gram flash booster is good choice. :)

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make slow flash coated rice hull and meal coated rice hull separately and mix them in a approx ratio of 3 :1, adjust the burst by varying the ratio to get optimum result as all the coated hulls may not have the same strength.

 

Just quoted from my pm, haha................But have you tried it ?? What was the result??

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I tried coat Nitrated fp on grass seed. It was more like white fast burning stars and it didn't work well for break. As swap said, you should you stronger burst like KP or H3 or just same bp with slow FP booster.
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i made a 2 inch shell with bp and slow flash burst will hope to test tomorrow will let you know how it turned out thanks for the info
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A quick search brought up this thread with some good information on flash boosters: http://www.amateurpyro.com/forums/topic/7542-flash-broken-shells/

 

A general "rule of thumb" that I have heard from several people about using 7:3 as a booster, is to use 1 gram per inch of shell eg. 4 grams in a 4" shell, 5 grams in a 5", etc. This has worked well for me, even when only using moderate speed BP on hulls.

 

 

WB

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yep bengalflair,

its quoted from your message and of course credit goes to you....i really appreciate you.

I really like your small shells break.

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A quick search brought up this thread with some good information on flash boosters: http://www.amateurpyro.com/forums/topic/7542-flash-broken-shells/

 

A general "rule of thumb" that I have heard from several people about using 7:3 as a booster, is to use 1 gram per inch of shell eg. 4 grams in a 4" shell, 5 grams in a 5", etc. This has worked well for me, even when only using moderate speed BP on hulls.

 

 

WB

 

That means in prortion to the amount of burst/stars/garnitures/volume exponentaily less flash is used as shell size increases. Probably wouldn't work so well for very small shells or inserts, I wouldn't use 1.5g of 70:30 in a 1.5" shell, but I don't find I need any flash booster in any of my shells, BP works fine for me.

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I am sorry but what does it mean 7:3 as a booster??
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I am sorry but what does it mean 7:3 as a booster??

 

That would be the standard formula referenced Perc/AL at that ratio... Lancaster European #2 where as #1 was 66/34 instead of 70/30.

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thanks aircow for the link i will try the shell tonight it is low tide so i will have plenty of area to try it. i did a slow flash of 2/1/1 of potasium nitrate, sulfur, and -325 aluminum and i have 4f bp as the filler around the stars the slow flash i put in the cunule then removed it
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well shell did not go so well i had a flowerpot will have to start top fusing will test another one in a few days will let you know how it goes
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Sorry your shell flowerpotted. You might need to work on your shell building technique a bit. I don't really see a 2" shell needing top fused. I only say this because I've been bottom fusing 2.5" canister shells without issue. Well my first one flowerpotted as well but that was due to my end disks not being up to par. Hope your next one goes better.
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this is only my 3rd one since i started making them i really think that the time fuse blew into the shell
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That would be the standard formula referenced Perc/AL at that ratio... Lancaster European #2 where as #1 was 66/34 instead of 70/30.

Thank you Hoppy.

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this is only my 3rd one since i started making them i really think that the time fuse blew into the shell

 

When I make shells i always (regardless of the size of the shell) put a piece of a paper tube around the time fuse outside of the shell and fill this tube with melted glue to prevent the fuse from blowing in and making a prefect seal. Leave at least 1 cm outside of the tube to allow cross matching.

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this is only my 3rd one since i started making them i really think that the time fuse blew into the shell

 

While it's possible, I suspect you probably had a leak somewhere. I've successfully fired many bottomfused 5" and a few 6" cylinder shells with no issues what-so-ever. While the fuse may have blown in, it was due to construction not inherent flaw in cylinder shell properties.

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thanks mumbles i looked at the shell casings i have already made and the 1 i grabbed was from a pile that i have not gorilla glued the time fuse so my bad
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i shot up that shell lastnight with 2 grams slow flash and the rest bp looked better for a burst. i built another shell today with 3 grams fp 70/30 and the rest meal powder will let dry any test tommorrow night fingers crossed for a good shell
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Your using meal as burst? Thats your problem right there.

 

care to elaborate?

I use coated rice hulls no booster

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