Making my dragon eggs louder and less crackles

[insutama]

Im just wondering what im doing wrong i have tried many different ratios of Bismuth trioxide, magnalium -200 mesh, copper oxide, and 10% NC laqour from double based smokeless powder. Is there anyway i can make my dragon eggs louder without having to buy more corse mgal ?

[lloyd]

From my own experience, the coarseness of the Mg/Al has the most effect on timing of all the variables, but I make crackle with -200Mg/Al of which each grain explodes only once, loudly. I control the delay-to-burst by varying the prime layer's thickness. The difference, I think, is that mine also includes fine spheroidal aluminum, and I try to control the particle density and particle sizes well.

 

It makes a difference in timing how porous and/or irregular the grains are. I try to keep the porosity low and the shape roughly spherical by gently 'hand rolling' the bits through the sizing screen in the last sizing pass. Whatever gets crushed by that method can simply be re-wet with acetone, and processed again.

 

Material grams

Bismuth Trioxide 71.2

MgAl 200m 14.4

Black Copper Oxide 9.4

Atom. Alum 12 micron 5.0

100.0

 

Use no less than 2.65% (up to about 3%) of the dry mixture's weight in double-based powder for the NC binder, dissolved in 'enough' acetone to make it a pourable consistency. I use about 1 part powder to 8.5-9 parts acetone. (w/v, for instance, 60g in 500ml)

 

This will make an almost 'batter-like' mixture. Make sure to use ALL of the NC mixture per batch. For instance, at that concentration, I use 60g of Green Dot in 500ml acetone for each 5lb of dry power mixture -- and ALL of it!

 

Continue to stir and mix the mass until it becomes a stiff-enough 'dough' to begin screening 'worms' for final sizing.

 

-8+10mesh particles for 22-30mm comets, -6+8 for 38-45 mm comets.

Also -6+8 for small 'crackle-only' mines or crackling pistils.

Roller-prime with 'rough powder' mixture with +6% dextrin, using potassium dichromate saturated-solution for the wetting water.

 

'Hope that helps.

Lloyd

Edited July 3, 2017 by lloyd

[insutama]

Great thanks lloyd, I also use spheroidal aluminum and 200 mesh mgal i think what im gonna try is using less NC laqour i was using 10%, also normally i was using a 10 mesh screen to push the comp threw and didn't bother to try and roll the pieces by hand into spherical balls. I also never bothered screening the dry eggs i just put all the dry eggs together in one container . Another thing im wondering is if making micro batches say 10 grams dry weight plus .3 grams, would this maybe have something to do with not getting loud single pops rather than crackles. In the past i have been working with 10 gram batches just so i could perfect it in small batches then when i have it figured out i would make 100g batch.

 

Im not gonna have time to try and make them today so anymore advice from anyone would be great.

[lloyd]

Batches that small are EXTREMELY difficult to weigh properly, and crackle relies on fairly-accurate measurements of the chemicals. I suspect you should 'amplify' that project to about 100g.

 

Lloyd

[insutama]

okay i will try that next time and and ill try the ratio you gave me. thanks

[Mumbles]

If you want to make batches that small, you better have a pretty accurate scale. Ideally, you want a scale accurate to probably 100x the smallest quantity you're measuring. This introduces about a few percent error into the mass measurement in most cases. If you have a scale accurate to +/- 0.1g, and are trying to measure 50.0g, depending on the listed accuracy the mass will likely be somewhere between 50.1-49.9g, though realistically the mass is probably somewhere between 50.2-49.8g. It may say it's accurate to +/- 0.1g, but unless you're dropping serious coin on a good scale I wouldn't necessarily trust it.

 

You can fudge these guidelines a little bit for non-critical components, but I wouldn't go lower than 50x and expect any real certainty in the measurement.

[insutama]

My scale i use was a pretty decent one it messures to .01 up too 500.00 grams would this scale be good enough for 10 gram batches?

[greenlight]

Does anyone have suggestions for making crackle into stars for 3 inch shells? Would they be cut the same size as normal colour stars for the shell or smaller? So far I have only used the crackle as riced grains in mines.

[lloyd]

For the sort of effect where stars terminate in crackle, rolling stars using sized crackle for cores is the way it's done.

 

Adding crackle to composition for cutting will give stars that crackle through their entire flight.

 

In either case, you'll get a better effect if you tightly size the crackle bits, so that their crackling is uniform in loudness and burst appearance.

 

Lloyd

[greenlight]

Thanks Lloyd, that questions been bugging me for a while.

[insutama]

Would a formula using less bismuth be as effective for louder single cracks? Just wondering seeing how its the most expensive chem

[lloyd]

Before you try reducing anything, why not try the stated formula, first? It's known to work correctly. Once you get it working, you can use it as a basis of comparison for other mixtures with other proportions.

 

I'm constantly fiddling with formulae. For me, that's as much fun as shooting, But -- My personal philosophy is: "Don't re-invent anything until you've mastered making it the 'original' way!"

 

Lloyd

[insutama]

Fair enough lloyd when im back from work tomorrow im gonna try a batch im nervouse making a 100 gram batch and it not working but then again if the reason my eggs just crackle rather than explode is because im making too small a batch then id better make a 100g batch

[OldMarine]

I'm on my 5th batch using Lloyd's formula (but not his volume) and have had great success even though most of my last batch resembled mouse turds more than spheres.

[insutama]

what volume sized batch do you make ?

[OldMarine]

I make a 22.5 ounce batch which uses a pound of bismuth trioxide. Keeps it simple and I don't use the bismuth for anything else so I'm not trying to save any.

[insutama]

I just made a small batch if this dont work ill try making a bigger batch i find its very hard making a dough with nc laqour so sticky

[lloyd]

You're doing something wrong if you're trying to follow my instructions. The 'dough' will turn out to be almost a 'batter' when all the NC lacquer that's required is added.

 

If you're making it by the 60g/500ml formula (regardless of the amount you make), the lacquer should be 'pourable', and the dough will turn out WAY too-thin and liquid until you've evaporated a good bit of the solvent from it.

 

Don't ask me... ask Patrick. He's made it.

 

Lloyd

[OldMarine]

I add plenty of acetone while mixing the lacquer which makes it easier to then mix in the rest of the chems. The acetone evaporates very quickly so you can go from thin batter to dough in minutes. I keep a spray bottle of acetone to dampen the comp as I'm cutting it in case it starts getting too stiff and keep the bowl covered tightly while letting it (me) rest. Definitely doesn't hurt it a bit to over wet with the solvent.

[insutama]

Are u suppost to let it rest for awhile before cutting ?

[OldMarine]

You'll need to rest yourself after mixing the lacquer! I let it sit covered for a bit to let the solvent even out but it may not be necessary. It's worked for me so I stick with it plus I do it in portions since I don't have but 12" screens to cut it through.

Other than BP and Tiger Tail stars this was the first comp that worked the first time I tried it.

Edited July 6, 2017 by OldMarine

[insutama]

Do you mix it in a bowl or glass or just on the kraft paper ? I was mixing mine in a stainless steel mixing bowl i found alot of the comp was wasted sticking to the bowl. If i have time tomorrow im gonna try again with 100g batch. Also when mixing the comp with the nc laqour do you use a stir stick or spoon or do you work it into a dough with gloved hands. I have been using gloved hands and i find i get so mucb sticking to my gloves and not been able to get it off the gloves and into my dough Edited July 7, 2017 by insutama

[Mumbles]

Mechanical loss goes way down when working with useful quantities. You can always rewet the bowl and scrape it up at the end to process it. You need to clean it out eventually anyway.

[OldMarine]

I mix the lacquer with a stick and start mixing the dry chems in with it but the comp quickly gets so thick you have to use gloved hands to finish the process. The comp will crumble from your gloves after only a minute's drying time and as Mumbles said the bowl can be spritzed with acetone and scraped down. I enjoy tossing the gloves into the burn barrel after I'm finished because I often get a few good pops out of them!

[lloyd]

Patrick, if it's getting that thick, there's something wrong with your NC lacquer quantity or proportions.

 

When I make the stuff, it turns out like (pretty thick) pancake batter, and must be stirred for a time to release the excess acetone. It takes probably 10 minutes of agitation to get it to the consistency necessary to begin granulating it.

 

LLoyd