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Posted (edited)

Can somebody post the composition for win39j as well as a burn rate table for 1lb. Motors?

 

Edit: Burn rate for the delay not rocket fuel for 1lb. Motors

Edited by Jordan
Posted

Winokur 39J

 

Potassium Nitrate - 51

Airfloat Charcoal - 19

Antimony Trisulphide - 12

Atomized Aluminum 120-325 mesh - 9

Barium Carbonate - 5

Dextrin - 4

Magnalium -60 mesh - 2.5

 

Sorry, I don't have the burn rates handy.

Posted

2 -3 seconds per 3/4". depends on how well you mix the comp :-)

Posted

Could I replace barium carbonate with strontium carbonate or sodium carbonate, bicarbonate?

Posted

You could replace it with strontium carbonate or sodium bicarbonate, but the effect will be different. Win 39 is quite a unique effect when done right, so these modifications may kill it.

Posted
Speaking of 39J, I noticed Tom joined APC yesterday...
Posted

Speaking of 39J, I noticed Tom joined APC yesterday...

 

Big Brother is watching you :D :D :D

Posted

I would advise to omit the dextrin and replace 1:1 with Red Gum.

Posted

By Tom, do you mean Tom Rebenklau? Is he the guy that made 39j?

Posted

I would advise to omit the dextrin and replace 1:1 with Red Gum.

 

 

I would advise not to do that. Red gum will kill more glitters than it allows. For a delay you don't need any binder whatsoever anyway.

Posted

By Tom, do you mean Tom Rebenklau? Is he the guy that made 39j?

Yes

Posted

How come people think red gum is like ketchup, which is/has been put on almost everything?

Posted

Hee-hee! It's like Franks Hot Sauce...

Posted (edited)

Nasty stuff, that red gum is. Goes everywhere. Kind of like thermal heat sink paste for electronic use.

Edited by Bobosan
Posted

How come people think red gum is like ketchup, which is/has been put on almost everything?

Wait... Your saying it isn't? If the color is right, and the consistency... Put it on your pasta, don't spend to much time tasting it.

 

Actually. I think it's simply down to it's properties as both a fuel, and a great binder. I prefer to use straight water as a binder, or water / alcohol when i need something with a lower surface tension... So redgum wont work for me. But it IS great. Almost like ketchup.

B!

Posted
If red gum is ketchup, what's phenolic resin... A1? :)
Posted

I don't know about that. To me, phenolic resin smells like it has a hint of menthol like the Chloraseptic spray for sore throats.

Posted
Ha... that's the smell. It's been driving me crazy trying to remember where I've smelled that before. I always hated that spray stuff...
Posted

I'm cheap because I'm a "user"! Dextrin and water are cheap for a binder and a solvent respectively, and work very well, alcohol and red gum are not.

Posted
I am now a convert to phenolic resin and alcohol for my color stars. I am finding it to be a superior fuel to red gum and a great binder. I use dextrin and water for charcoal stars, cheap and effective.
Posted (edited)

Could I replace barium carbonate with strontium carbonate or sodium carbonate, bicarbonate?

 

I was making 3" comets with a variation of 39J (oh so many years ago) and had only half enough BaCO3. I made up the difference with SrCO3 and pressed the comets. When fired, the comets performed very well, but with a subtle surprise. When two of them were attached to a 12" shell for a rising effect, I thought I could see the tiniest little red and green flashes in all that white glitter, and wondered if I was imagining it, when someone came up behind me and asked, "Are those red and green flashes in that glitter?!"

 

I would avoid sodium carbonate in glitter compositions in any case because it's strongly alkaline and will attack the aluminum.

 

WSM B)

Edited by WSM
Posted (edited)

When you use W39j for your delays, how do you prepare it?

With or without binder?

Riced with water?

Do you ballmill the composition, at least the BP parts?

And how must the charcoal be, a fast one or a slow one?

Edited by dangerousamateur
Posted (edited)

TR only uses commercial hardwood airfloat charcoal... so nothing special.

 

Since you asked for using it as a rocket motor delay, the binder isn't necessary.

 

I would screen all the ingredients (except the mg/al) through a forty mesh screen, until mixed well. Then add the mg/al and mix/stir.

 

You can press dry.

Edited by ddewees
Posted

I prefer to granulate all of the comps that I end up pressing, it makes the process much less dusty and I think granulated comps press into a better grain. A binder isn't necessary, just dampen the comps with water and granulate through a 12-20 mesh screen. I do use a binder, even in rocket delay, but it is not necessary. I think it just makes grains that store nicer without breaking down into dust again.

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