Black Match, humidity, and leader tube size

[BetICouldMake1]

So I took my first stab at black match. Mixed up a batch of slurry using bp meal + 10% dextrin, used 2 strands of 3 strand cotton string coiled together and dunked/ massaged in slurry. Stretched those out across some nails and dried for 3 days until stiff and crispy. Cut a section to test and it burned a bit slow but nice and even. Cut the rest into 2 ft sections wrapped in a newspaper tube for storage.

 

Took some out 2 nights to test out as quickmatch using 1/4 id tubes rolled with newspaper. But I noticed as soon as I took them out that they felt softer than before. Tried burning a section outside the tube and it spit and sputtered along, barely. Tried it in the tube and it seemed like the tube put the match out rather than speeding it up.

 

Since the sun finally came out yesterday I took all the match out and spread it on a screen. Got nice and crispy again in about an hour. Bare pieces burned fine as did strands in leader tubes. Left them on the screen and later that night I went to get them and once again they were limp and wouldn't burn.

 

 

I know charcoal and bp in general are hydroscopic but would high humidity alone take blackmatch from perfectly functional to unburnable in a matter of hours or would too little slurry or poor ratios contribute to my crappy match? Maybe it was just never fully dry in the first place?

 

I've ordered a gun safe style dehumidifer for my magazine to at least minimize moisture during storage but is match that susceptible to moisture and if so how might I protect it on finished items that might sit outside storage for some time before firing?

 

On a related note, can a leader tube ID relative to blackmatch thickness affect burn rate positively or negatively?

 

Any suggestions?

[OldMarine]

10% is way too much dextrin. That's probably what is taking moisture back up. I use 2% dextrin and 1% CMC in mine and get a very stiff match. You don't need the CMC if you're kneading the hank of string in the slurry. I use a black match machine so I use the CMC to keep everything in suspension. Edited August 5, 2018 by OldMarine

[pyrokid]

If charcoal is hygroscopic, it is not so to the extent that the performance of pyrotechnic devices would be degraded as you describe.

 

On the note of leader tube ID, knots are frequently tied in finale chains to add a small delay. The knot interrupts the passage of hot combustion products down the tube. If the tube is too large or has leaks, the speed of the QM will decrease.

 

OldMarine is absolutely correct with his comments.

[BetICouldMake1]

Doh, yes, hygroscopic. Thanks guys. I though 10% seemed high but it seemed like most of the formulas I could find had pretty high dextrin percentages. I'll mix up another batch @ 2% and see how it goes.

 

 

Is the CMC necessary if using a black match machine? I know some people use CMC rather than dextrin but I'm not really sure what the advantage of one over the other is. I think I heard that CMC works well for black match because it binds well but is more flexible than dextin (less prone to cracking/flaking), is that accurate?

[Arthur]

IMO and only that! BP will function at 3 - 5% total binder. 2% and less it falls apart unless pressed and properly corned. 5% and more it's over fuelled and slows down.

[OldMarine]

I'd use 5% dextrin if not using CMC to insure proper binding. A fuse that burns fairly slow when exposed will still burn almost instantly when placed in a pipe.

Cmc doesn't make a really good binder alone imho.

Edited August 7, 2018 by OldMarine

[BetICouldMake1]

Thanks guys, I mixed up a batch with 3% dextrin and have it drying now. I'll let you know how it goes.

[pyrohacker]

Greetings

I don't have access to quickmatch. Does anyone knows what's the exact width of a Chinese made quickmatch fuse?

[SKC]

BetIcouldmake1, same had been the case with me earlier with matches. I was quite unsuccessful of making good black matches inspite of being able to make some fireworks.

Hope your drying batch satisfies you, still just browse on the following. It might help to make good black match everytime. It's standard for myself.

1. Choose 2 entire sunny day.(morning to evening)

2. Select strands units wisely.(The texture of the strands should not be very thick or one may have problem to impregnate with composition. The core may remain unimpregnated. Choose a little loose type. I selected jute strings, damn cheap)

3. Fine mesh of composition with 4-5% dextrine.

Start early morning, dry in shade for 4-5 hours then under direct Sun. Entire next day direct under Sun.

 

This never let's me down in account of black match.

[Mumbles]

I would like to second your drying advice. Blackmatch always seems to take a day longer than you think to dry. It will feel dry, but it always seems like the core is still wet for at least a while longer. If you burn a test batch, seeing glowing string embers is usually a sign it's still a little wet.

[BetICouldMake1]

Hey, I remember this thread. Happy to say that batch of match did work, as have my later batches. I make mine using multiple strands of crochet thread, so it drys pretty quickly. I usually leave it to dry on a warm sunny day for a few hours, then cut to length and hang the bundle to dry indoors for another day. Just really rainy where I am so I prefer to get things inside quickly. I also like using the thin strands because they take up the slurry so quickly, plus I can make round or flat match. The flat is nice for top hatting or cross matching and it lays down well in a passfire.