My 1st 4inch cylinder shell

[THEONE]

Here is my 1st 4 Inch cylinder shell with TT stars. I used 4g of whistle mix into the burst center as a booster. Your opinions?

 

P.S. The shell was a little bit loose into the mortar so i believe that is why it did not as high as i was expecting.

 

Thanks

Edited February 26, 2022 by THEONE

[Carbon796]

That looked like it worked very nicely. Congratulations on your first 4" !

[MadMat]

Well done!! I don't understand what you mean; the height looked good on that shell. The timing of your time fuse looks like it went off just after reaching apogee , so any higher of a flight and it might have gone off while still in ascent. If there was anything at all to work on I would say maybe a bit harder of a break, unless, of course, you were going for the "waterfall" type effect you got. In that case it was perfect.

Edited February 27, 2022 by MadMat

[THEONE]

Well done!! I don't understand what you mean; the height looked good on that shell. The timing of your time fuse looks like it went off just after reaching apogee , so any higher of a flight and it might have gone off while still in ascent. If there was anything at all to work on I would say maybe a bit harder of a break, unless, of course, you were going for the "waterfall" type effect you got. In that case it was perfect.

Thanks Carbon.

 

MadMat thanks for your reply. After watching the video again, i was wondering, did it broke correctly or it popped from the top / bottom, like a mine (Draw out effect) ? I think all stars went outwards. I can not see any star in the back so i was wondering if the break was even. What is your opinion ?

Edited February 28, 2022 by THEONE

[Carbon796]

TT is more to the slower side of charcoal streamers. So it will tend to hang longer/willow more, than others. Depending on star size and break strength somewhat.

[Maserface]

Definitely a nice job! You can fine tune the little things but having your shell leave the gun and break in the air is a great start.

 

Did you use a spollette? What timing were you going for?

[MadMat]

 

 

MadMat thanks for your reply. After watching the video again, i was wondering, did it broke correctly or it popped from the top / bottom, like a mine (Draw out effect) ? I think all stars went outwards. I can not see any star in the back so i was wondering if the break was even. What is your opinion ?

It looks like your spiking was done properly as you didn't get the "horse tail" effect of a shell breaking from the ends. Your break looked round and symmetrical. What I was talking about is your stars falling downward almost immediately. If you would have had a slightly harder break, you would have had a bit more of a "puffball" effect to your star pattern... sort of like a dandelion flower after going to seed. This kind of effect is easier to obtain with ball shells, but can be done with cylinder shells as well.

Edited February 28, 2022 by MadMat

[THEONE]

Maserface i used a spollette yes. It was top fused with a bucket, crossmached and primed with NC/BP. I was looking for about 4 sec delay. It is not my 1st shell, i have made a few smaller shells like 2 inches or smaller but i just now did the step to 4inch. My smaller shells also did not have a good break because i did not use any booster, only BP. The problem is that i can not buy kclo4. In that shell, i used 4g of whistle mix where i harvested it from commercial small whistles. I have read that the best booster is 35/35/30 kclo4/kno3/al, so i am thinking to buy a few firecrackers, extract the FP and cut it 50/50 with 70/30 kno3/al.

 

MadMat i am really happy to hear that my spiking was properly, thanks. As i said before, the problem is the booster. I don't have access to kclo4. I have about 10 kilos of kclo3 made with a MMO anode and right now i am making some kclo4 with a Pt anode. Density and current are low, it runs at about 1amp but i am getting perchlorare, just need to be a bit patience till i get enough. Is there any other booster that it does not require kclo4 ? except the kno3 flash, I dunno if that flash is going to do anything. I have 325 mesh mgal and dark AL

Edited February 28, 2022 by THEONE

[Carbon796]

5:3:2 SFB works well enough. As does a more traditional forte nitro, if you have access to barium nitrate. Neither one will be as sharp as a KP based one. But that doesn't mean their not useful. What's the best booster is subjective. Like what's the best red, or blue, or charcoal streamer. I would avoid trying to salvage commercial items for supplies. Its tedious, potentially hazardous, and probably not cost effective.

 

I tried using whistle for a booster, a couple of times. It never really did " it " for me. Plus it wasn't something I regularly made/used. Where a metal fueled booster seemed like a better fit for me.

Edited March 1, 2022 by Carbon796

[THEONE]

5:3:2 SFB works well enough. As does a more traditional forte nitro, if you have access to barium nitrate. Neither one will be as sharp as a KP based one. But that doesn't mean their not useful. What's the best booster is subjective. Like what's the best red, or blue, or charcoal streamer. I would avoid trying to salvage commercial items for supplies. Its tedious, potentially hazardous, and probably not cost effective.

Ok i may try the 5/3/2. Shall i use dark al or mg/al for that flash? I do have barium nitrate, is it better from potassium for this purpose ? I have read somewhere (don't remember exactly where) that the optimum is actually KNO3 53% Al 33% S 14%

[Carbon796]

Supposedly if iirc, barium is a "slaggier" oxidizer.

 

Watch out for "people" trying to tell you what the optimum formula is. Sometimes there are specific reasons why a traditional formula may not be developed to be optimally balanced, that may not always be clear. A formula may be over fueled or under fueled. For a specific purpose. Some may be for economics, some may be for a specific performance/attribute.

 

Mastering the basics, with known formulas and techniques. Will get you farther ahead, faster initially. Than trying to fine tune, every possible optimal detail.

 

I would use the dark AL for boosters. Save the Mg/Al for the colors.

Edited March 1, 2022 by Carbon796

[THEONE]

I see, thanks Carbon, i appreciate.

[MadMat]

Just adding a couple % of dark aluminum to your BP can boost things up a bit. I make pretty hot BP and have only needed to add a boost of any sort to my cylinder shells smaller than 3". I have added booster to some of my 3" shells, but not all. Did you use simple granulated BP or coated rice hulls/puffed rice/ or some other medium?

[Maserface]

Maserface i used a spollette yes. It was top fused with a bucket, crossmached and primed with NC/BP. I was looking for about 4 sec delay. It is not my 1st shell, i have made a few smaller shells like 2 inches or smaller but i just now did the step to 4inch. My smaller shells also did not have a good break because i did not use any booster, only BP. The problem is that i can not buy kclo4. In that shell, i used 4g of whistle mix where i harvested it from commercial small whistles. I have read that the best booster is 35/35/30 kclo4/kno3/al, so i am thinking to buy a few firecrackers, extract the FP and cut it 50/50 with 70/30 kno3/al.

 

Gotcha. I recently built a few 4 cylinders and went with a 2.6 second delay (1 of my powder). I probably could have gone another quarter inch or so.

 

without potassium perchlorate, Id probably be trying a nitrate flash booster (granulated, mixed with my polverone), or likewise with H3.

 

https://youtube.com/shorts/ir3Ck4i2-VE?feature=share

Edited March 1, 2022 by Maserface

[THEONE]

MadMat i used granulated BP witch was granulated with a 10mesh screen, so probably a 2-3FA. Also i used the same for my lift charge. I used a canule for building that shell and during filing it, at the end of the blachmach coming from spollette, i added 4g of whistle mix, then added more BP till it was full. I pressed hard the 1st end disc so everything became solid, spiked pasted e.t.c.

 

Maserface do i have to granulate the FP or did i misunderstood ? Also is it better to add the booster all at once at the center of the shell, or mixed it up with BP ? Mumbles said that putting it in the center of the shell is much more efficient.

[MadMat]

A few questions: What was the diameter of your canule and did it run the entire length of the shell? Did you add any polverone to fill in the gaps between your stars? About using flash as a break booster; no you don't need to granulate the flash. A common practice is to use a flash bag. While others just add the flash evenly throughout the break charge as the BP is added. Personally, I think the use of a flash bag is somewhat safer. As far as using granulated. Yeah you can use simple granulated, but 4 inch shells are usually the size where guys start using coated hulls.

Edited March 1, 2022 by MadMat

[THEONE]

A few questions: What was the diameter of your canule and did it run the entire length of the shell? Did you add any polverone to fill in the gaps between your stars? About using flash as a break booster; no you don't need to granulate the flash. A common practice is to use a flash bag. While others just add the flash evenly throughout the break charge as the BP is added. Personally, I think the use of a flash bag is somewhat safer. As far as using granulated. Yeah you can use simple granulated, but 4 inch shells are usually the size where guys start using coated hulls.

It was about 45mm. Yes it run the entire length of the shell. Yes a added polverone to fill the gaps between my stars. I used polverone as a break, no coated hulls. I did not you a flashbag for that shell, just drop the whistle mix at the center of the canule, at the end of the blackmach spollette, like you do with ball shells.

Edited March 1, 2022 by THEONE

[MadMat]

Your canule was 45mm in diameter? That's rather large! For a 4" shell the canule should be 25-30 mm in diameter. I also agree with Carbon796, whistle has never really been something I liked for boosting a break charge.

[pyrokid]

Fast granulated BP in the cannule should give a much healthier break than with polverone.

[MadMat]

Pyrokid, earlier he posted that he used granulated BP for his burst charge, so... ??

[THEONE]

If i used 4FA (4 mesh) would the break be better? I used 2-3FA (10 mesh) Edited March 3, 2022 by THEONE

[Carbon796]

2FA is made by screening/consolidating through a 3 mesh screen. It is usually graded at about -3+8 iirc. Your -10 grade is much finer. Because of the surface area and smaller grain size. It should give you a slightly denser fill, and increased burning speed, in smaller shells. In larger shells it may be counter productive. Edited March 3, 2022 by Carbon796

[THEONE]

Yea that is what i was thinking. Maybe a 4FA would be more suitable for the 4 inch

[THEONE]

Few days ago i just fired my 2nd 4 inch. That time it opened about 50 meters above the gun. It was almost like a mine. I do believe this was happened because the pressure inside the bucket actually pop out the rammed BP from the paper tube (spollette) and the fire passed inside the shell. This is actually my 1st time i see something like this and i have never seen something similar happened anywhere. Any ideas how it can be fixed ? I was thinking to cut the bucket somewhere so no much pressure is going to built up. Any thoughts ?

[Carbon796]

If it goes in the gun, it's called a flowerpot. If it goes right out of the gun, its called a muzzle break. At 50 meters above the gun, it's just a low break. If it wasn't meant to open that early.

 

It it was a pressure issue with the bucket. ( as your theorizing ) It would have been a flowerpot.

 

Though that is very unlikely to happen. Unless your spolette's are very poorly made. With just a few thin wraps of kraft for the bucket. It's never really going to develop enough pressure, to cause any damage.

 

Do you build Rin-ed shells or pasted shells ?

 

What do you use for spolette tubes.

 

What number spolette did you use for the shell ?

Edited March 16, 2022 by Carbon796