Jopete's purple stars ruined by heat ?

[kaotch]

@ JOPETES

This is an ENGLISH forum why should we use an translator while you could use it as well.

[MinamotoKobayashi]

Hello Kaotch, nice to see You again.

And again thanks for the thing we know, they works always fine !!

[kaotch]

Hello Minamota,

Keep on destroying your foramulae!

[MinamotoKobayashi]

Jopetes, exposing the stars to an intense heat like a Summer sun could ruin the effect?

I read that some kind of stars doesn't like the direct sunlight.

Perhaps the glitters stars or other water-based stars with metals?

Edited July 26, 2020 by MinamotoKobayashi

[JOPETES]

Minamoto, take 20 or 30 stars and put them to dry in the sun for 2 hours and tell me if they have finished drying. if they have dried you can burn 2 or 3 stars on the ground and we see the result.

[kaotch]

Start to read the posts of "braddsn" who is very experienced with these formulae, search will be your friend!

[MinamotoKobayashi]

Found a lot of very interesting things, thanks!

Jopetes, I putted the whole 1.5 KG set of stars over a large 4 mesh sieve, and left over an intense sun plus noticeable wind from 7 A.M. to 8 P.M. 13 hours of hell.

The whole set has lost only 20 grams. Not all the stars are solid, some are again crushable between the fingers.

This is the most absurd thing that I can see from the beginning of the whole story. Please remind that these stars are 7 days old. Three full days under of an intense airflow and an entire day inside in my dehydratator at 40 °C. And now 13 hours in a hell of heat. Impossible, isn't it? I will expose the stars for extra 13 hours to the sun, then, dried or not dried, I will use them inside my new double petalled 8" shell. I will try to make stars with 50-50 alcohol-acetone.

If I will se again issues I switch back to red gum.

It seems that my phenolic resin try to keep the alcohol tight like the politicians do today with their chair ...

Edited July 27, 2020 by MinamotoKobayashi

[Carbon796]

You do realize that those formulas originated from/were distributed by Jopetes.

[JOPETES]

minamoto, have you ever tried red 1 of the pdf? It is a very good red and you will not have problems with humidity. you can use 70/30 or 60/40 alcohol water.

[MinamotoKobayashi]

Carbon796 I know, they are public domain.

Some times ago Jopetes has gently given me the PDF with all his stars and primes.

I have modified them to use only alcohol as binding agent.

 

Update: finally all the red stars was rock solid!

I can throw them on the floor with force but they do not flake or break, rather they bounce with a dry and precise sound.

I have found only one star not dried.

But there were issues.

First of all I used, as strobe core, the Shimizu's formula:

 

Barium Nitrate 51%

Potassium Nitrate 8%

Magnalium 230 13%

Sulphur 23%

Dextrin 5%

 

I used only demineralized water with a drop of ethanol.

The cores was perfectly dry and strobing as it should have been.

This strobe cores have had very strange behavior:

 

1. For the purple stars I used 70% water and 30% ethanol in the mix. I wrongly cooked them in my dehydratator a 70 °C for many hours.

The stars was under an heavy airflow for many days and then 13 hours under a direct sunlight.

The colour was totally washed but the cores was (badly) working.

No prime was used between strobe and purple.

The Jopete's modified formula was:

 

27 Potassium perchlorate

27 Strontium nitrate

09 Copper oxide

10 Red gum

13 Parlon

10 Magnalium, 230-mesh

04 Dextrin

+ 5 grams of Titanium 100-250 mesh for the tail

Diameter of the stars: 20mm

 

2. For the red stars I used only ethanol.

The red was intense, dazzling and long lasting, but incredibly the stroboscopic effect didn't happen!

Red effect from start to finish, not even a strange or washed color, nothing at all!

No core left, only few ash.

No prime was used between strobe and red.

The Jopete's modified formula was:

 

24 Potassium perchlorate

24 Strontium nitrate

11 Strontium carbonate

10.3 Phenolic resin

12 Parlon

15 Magnalium 230-mesh

+ 5 grams of Titanium 100-250 mesh for the tail

Diameter of the stars: 20mm

3. I created red stars same as above but much smaller, about 5mm diameter, monocapa primed.

They was perfectly dried in only a day under and intense airflow, no heat.

Perfect ignition, good red, perfect strobing.

At this time I'm really confused because I cannot recognize where is the problem.

I have understand only one thing: phenolic resin with big stars had driyng issues.

I'm making a new batch of green stars. Same diameter same phenolic resin, but I will apply a Monocapa layer

between the strobe core and the green mix.

I will be forced to use 70% water 30% alcohol+acetone to activate well the monocapa, also because strobe mix is water based,

and an alcohol-based prime surely do not grab well around the strobe core walls.

Besides this I will use a mix of 50% ethanol and 50% acetone for the green mix, no dextrin. This time no direct sunlight, only dehydratator at 40°

Here is the fierce burning and intense red of the 20mm red2 Jopete's star (with missing strobe):

https://www.youtube.com/watch?v=-dTVuRfH_II

This is a mini mortar with some dragon eggs and 9x5mm stars.

Strangely the stars dried in a day without heat and the strobe core was working:

https://www.youtube.com/watch?v=BXJ1ZWZebNU

No Jopetes, I haven't tried red1, because You have told me that this kind of red is slightly better.

Edited July 28, 2020 by MinamotoKobayashi

[Mumbles]

Have you been rolling your stars from the strobe core directly to the 20mm final diameter? Based on what you said about smaller stars working and the issues with drying, it may indicate that you're basically driving the stars in. This is a known problem with rolled stars if they're rolled to too large of a diameter in one session. Have you considered trying to roll them up to size in a few different sessions, drying in between?

[MinamotoKobayashi]

Yes Mumbles, 20mm diameter in one unique session.

But I also created 30mm winokur39J water-based stars in one unique rolling session without any kind of issue!

This means that this kind of issues happens only with alcohol-based stars?

Anyway I will follow Your precious suggestion, I will roll green stars in more sessions!

Edited July 28, 2020 by MinamotoKobayashi

[ExplosiveCoek]

Have to agree with Mumbles here, especially since you cooked them at a higher temperature the stars' outer layer can become dry, whilst the inside can stay wet 'forever', an the SrNO3 isn't helping here either. Had same thing happen with some willow stars and finally had to tosh them.

 

They wouldn't have a clean burn anymore either, just leave some round shell of ash. Perhaps this is also what is disturbing your strobe cores. Too much enclosed heat that isn't able to get away.