CMC

[TritonPyro]

Is this a binder? Can it be substituted? It is used in a delay composition and I am not sure what it is. Thanks.

[Shadowcat1969]

CMC = carboxy-methy-cellulose = wallpaper paste

 

Used mostly when making tubes or pasting. I'm not sure if anyone uses it as a binder in compositions or not.

[flying fish]

It is sometimes used as a binder in compositions. Its binding strength is said to be very strong - to the point where you'd normally use half of the amount specified for Dextrin and still get much stronger stars. At least, I heard this from someone in my club who rolls stars with it. He talked us into doing a group buy of the stuff, so I'll get to see for myself soon. Edited April 6, 2013 by flying fish

[Algenco]

excellent binder for BP and blackmatch Edited April 6, 2013 by Algenco

[TritonPyro]

It is 0.5 g of a glusatz German comp. for delays . Wondering if something else can be subbed as buying a bag of this will last me until the rapture.

[Nessalco]

I use 3% dextrin +1% CMC when making slurry for blackmatch. The CMC keeps the BP in suspension very nicely. I also use CMC when I make wheat paste. A small amount adds 'tack' to the paste.

 

Kevin O

[TritonPyro]

Does anyone know if I can SUBSTITUTE for it. Thanks.

[TritonPyro]

Okay here goes.

Barium nitrate. 75.5

Charcoal AF. 10

Sulphur. 10

Meal powder. 3

Cabosil..............2.5

Dextrin. 4 parts

Screen all except dextrin which is added to warm water and then added to mix. It should be crumbly and not wet. Ram into tubes or whatever. Still damp at 1/2 inch wide and In a 4 inch tube it burnt at 45 seconds to the inch leaving a lot of white slag. It successfully ignited a BP bag at the end of tube. No CMC, just my trial shot.

 

By the way, smaller tube, faster burn time, best was a 10mm tube.

Edited April 6, 2013 by TritonPyro

[dagabu]

Man, if you weren't across the pond, I would PIF you a few ounces. You got it, Dextrin is your go to.

[TritonPyro]

Thanks dagabu, it is still successful although a little slaggy. The Germans use it for delays in firecrackers and it is useful for other things that I will try to work with.

[Mumbles]

I'm not totally sold on CMC as a universal binder, particularly for colored stars. It's often sold as the sodium salt, and it seems like blasphemy to me to intentionally add sodium to anything you don't want to be yellow.

[dagabu]

But it's nice for black match!