Shellac

[Tanner808]

what is Rosin?

and where can i get it?

Is it the same as shellac?

i am wanting to make yellow stars with this formula on pyrocreations.

 

Yellow star #4

Source: rec.pyrotechnics, posted by Tommy Hakomaki <tommy.hakomaki@mailbox.swipnet.se.

Comments:

Preparation:

 

Potassium nitrate.................................48

Sulfur............................................24

Mealpowder........................................60

Charcoal..........................................10

Rosin.............................................2

 

 

 

 

 

 

 

Edited January 26, 2012 by Tanner808

[Peret]

Rosin is pine tree resin, also known as colophony resin. It's fairly soft, melts at a low temperature and dissolves in alcohol. I've never used any for pyro and don't know who sells it, but since violinists rub cakes of it on their bows and gymnasts dust rosin powder on their hands and feet to avoid slipping, it must be fairly easy to find in general commerce. Shellac is quite similar in many ways but it's an excretion of insects, not plants. It melts at a lower temperature than rosin and contrary to most reports, does NOT dissolve completely in alcohol (though it may do if the alcohol is boiling). Several pyro suppliers have powdered shellac, including Hobby Chemical Supply. It has special properties for pyro in that it contains more hydrogen and less carbon than other resins so it burns without a yellow flame, and is therefore considered the superior fuel for colored stars. For some reason, though, it doesn't burn well with potassium perchlorate, only with potassium chlorate, so you mostly see it specified in chlorate comps.

 

The formula you quote above is for a charcoal star that doesn't need any rosin fuel at all. In this case it's being used as a binder, the star powder being moistened with alcohol. My experience is that would be a very difficult process to get right, since only the 2% of rosin would dissolve in the alcohol and therefore a small excess of alcohol will turn your compound into a mess like wet sticky sand. You'd do better to forget the rosin, replace it with 5% dextrin and moisten with water.

Edited January 26, 2012 by Peret

[petroleum]

what is Rosin?

and where can i get it?

Is it the same as shellac?

i am wanting to make yellow stars with this formula on pyrocreations.

 

Yellow star #4

Source: rec.pyrotechnics, posted by Tommy Hakomaki <tommy.hakomaki@mailbox.swipnet.se.

Comments:

Preparation:

 

Potassium nitrate.................................48

Sulfur............................................24

Mealpowder........................................60

Charcoal..........................................10

Rosin.............................................2

 

Some years ago I use this material in AP based stars. Burning rate of stars with rosin in a factor 1,5-2 slower comparing with shellac. But there is one advantage of rosin - it easily can be crushed in powder using simple mortar and pestle (especialy if material was cooled).

About the formula - I dont think, that it will give you good yellow stars.

[allrocketspsl]

that formular isnt going tog ive you yellow mate you need cryolite or sodium oxalate heres a link for shellac

 

http://pastimepyrochemicals.com/

[Dean411]

Some pipe.sealants are alcohol and rosin and that's all there is I picked some up.from.the hardware store left the cap off it and let the alcohol evaporate and then you can crumble up the rosin after it dries.

[warthog]

cryolite give more of an orange IMO, never gave Sodium Oxalate a try though, I will look for a few formulae.

 

I am now thinking that Mumbles and Lloyd S have it right and I am going to see if I can make myself a nice yellow from my good greens and reds. Time will tell and so will I when I manage to get this one done.

Edited January 27, 2012 by warthog

[Bonny]

I am now thinking that Mumbles and Lloyd S have it right and I am going to see if I can make myself a nice yellow from my good greens and reds. Time will tell and so will I when I manage to get this one done.

 

 

I've made a very nice yellow doing exactly that. The formulas I used (from Lloyd and posted on Passfire) for the green and red were not likely the best in either colour, but were very basic and only differed by using barium or strontium nitrate.

 

BaNO3 OR SrNO3 -5

Parlon -2

Red Gum - 1

MgAl(-200) -2

Dextrin +5 PERCENT

 

The basic mix provided for yellow is 3.05 BaNO3 and 1.95 SrNO3

This can be fine tuned to your liking, but a great start.

 

I simply mixed a good sized batch of red and green and then proceeded to make red, green and yellow stars (using the same ratio but with green and red comp for the yellow)

[petroleum]

cryolite give more of an orange IMO, never gave Sodium Oxalate a try though, I will look for a few formulae.

 

 

Yes, it is. But utilizing Ba(NO3)2 in yellow star formulation with addition of cryolite results to good yellow-lemon color (in my oppinion it is impossible to get good yellow (not yellow-orange) only with sodium salts, there must be some green part in the formula).

 

 

 

[Potassiumchlorate]

Like I said in my own shellac thread: I don't care much for yellow, but the few times I make it I use cryolite. Almost every other yellow-colourant salt is hygroscopic. Edited January 27, 2012 by Potassiumchlorate

[warthog]

Again, I assert that we have all been barking up the wrong tree by looking for a yellow colorant. The best yellows I have seen so far have been red/green (one of my favorite shows BTW) blends. I didn't care for yellows either until I saw a few of these in action. Now I am wanting to get myself into a position where I can start mixing up my reds & greens and blending them until I get just the right shade of yellow for myself. Once I get that sussed, I may well gain a new respect for yellow.

 

Thanks for the Tip Bonny!

Edited January 27, 2012 by warthog

[Bonny]

Again, I assert that we have all been barking up the wrong tree by looking for a yellow colorant. The best yellows I have seen so far have been red/green (one of my favorite shows BTW) blends. I didn't care for yellows either until I saw a few of these in action. Now I am wanting to get myself into a position where I can start mixing up my reds & greens and blending them until I get just the right shade of yellow for myself. Once I get that sussed, I may well gain a new respect for yellow.

 

Thanks for the Tip Bonny!

 

 

I think another set of red and green to try for optical yellows would be the ruby red/emerald green. IIRC they use the same base comp with barium or strontium.

[Mumbles]

Colors are colors. It's possible to achieve the same shades with a mix of sodium and barium or strontium. The main trouble is that sodium is so over powering it can be touchy. I honestly am not a fan of sodium yellows or calcium oranges. I've come to associate those particular colors with impurities, so it makes them a bit less appealing to me. To each their own. The yellow I was using before an optical yellow from barium and strontium does indeed use a mix of barium nitrate and cryolite. Going with the touchy comment before the mix has 60 parts barium nitrate to 8 parts cryolite. I never tried it, but the same mix with strontium would probably make a pretty decent golden color.

[Col]

I use red and green for yellow and orange. Not the purest colours but it saves mixing 2 dedicated comps that i won`t use much of. i always have plenty of red and green on hand.

http://www.youtube.com/watch?v=oL914kpVqqw

http://www.youtube.com/watch?v=ZV1qmzhH-Ts

[allrocketspsl]

I have a yellow that will knock your sox off

[Bonny]

I have a yellow that will knock your sox off

 

That's good for you! Why not share it rather than brag about it...