10 replies to this topic

[Stuart]

How are portfires made? They burn very slow for the amount to black powder (if that is what it is) in them. I would like to try making some, I love them:D, they are pretty kewl.

[Edited on 25-7-2003 by Stuart]

[BigG]

Portfires contain much higher percentage of sulphur then BP. Published formulations for portfires include:

Lancenster:

A: KNO3 60, S 20, BP 20
B: KNO3 60, S 16, BP 11, and Antimony Sulphide 10

Stay Green, BigG

[Stuart]

Thanks, got to make some!

[fishy1]

would making one from naclo3 (with a fire deppressant added) mixed with petrolium jelly work? just becuase i have a fair bit of naclo3 weedkiller that needs using. also, when making portfires, what dimensions tube should i use? thanks.

[RegimentalPyro]

would making one from naclo3 (with a fire deppressant added) mixed with petrolium jelly work? just becuase i have a fair bit of naclo3 weedkiller that needs using.  also, when making portfires, what dimensions tube should i use? thanks.

The fire depressant is probably normal salt, ie: Sodium Chloride.

If it is the Doff brand of chlorate weedkiller then the Sod.chlorate has a much higher crystal size than the relatively finely powdered tablesalt. Apply a sieve and you can purify the stuff fairly effectively.

However, the stuff has fairly few uses in pyro. The sodium colour [yellow] washes out any other colour might be trying to create. You can try converting it to Potassium Chlorate, but any chlorate comps are of course much more sensitive to friction ignition than the safer nitrates. Use that instead eh?

PS: [repeat after me]

I will never EVER allow sulphur or sulphur salts to be mixed with chlorates. Horribly dangerous practice!

[Mortartube]

Much better to use BaNo3 and red gum or accaroid resin formulations. Less smokey and a better burn. Funnel and wire them with a basic green lance mix. Make them about the same diameter as a lance and the length to suit, say 40 cm or so. Touchpaper or prime one end. Voila!!!

[fishy1]

The fire depressant is probably normal salt, ie: Sodium Chloride.

If it is the Doff brand of chlorate weedkiller then the Sod.chlorate has a much higher crystal size than the relatively finely powdered tablesalt. Apply a sieve and you can purify the stuff fairly effectively.

However, the stuff has fairly few uses in pyro. The sodium colour [yellow] washes out any other colour might be trying to create. You can try converting it to Potassium Chlorate, but any chlorate comps are of course much more sensitive to friction ignition than the safer nitrates. Use that instead eh?

PS: [repeat after me]

I will never EVER allow sulphur or sulphur salts to be mixed with chlorates. Horribly dangerous practice!

i know i could get the fire depressant out, it's pretty easy, and i have made kclo3 severaal times, it's just i thought if i kept in the firedepressant is would help it burn longer(that's what it did for me, and long burning is useful for a portfire.

[alany]

A cheddite-esk portfire strikes me as kinda stupid, not so much that it is potentionally detonatable but that it would be a fairly sticky and difficult to work with mix. if you must use Chlorate, why not a colour composition, like a nice slow red lance comp?

I tend to use Nitrate based white lance composition for portfires, very cheap and "broadband" light which helps see colours that can be poorly contrasting in the relatively monochromatic light of a fusee.

Working with Sodium Chlorate sucks anyway, I guess the petroleum jelly might protect it, but in the long run it just seems easier to convert it to the Potassium salt, or even electrolyse it up to Perchlorate first, seeing that most of the work has already been done for you. The pink lance composition that uses plaster of paris and shellac makes quite a nice portfire, and you should really only use Potassium Perchlorate for it.

[completebeginner]

Portfires contain much higher percentage of sulphur then BP. Published formulations for portfires include:
Lancenster:
A: KNO3 60,  S 20, BP 20
B: KNO3 60, S 16, BP 11, and Antimony Sulphide 10
Stay Green, BigG

would this mixture be a suitable replacement for dan wiliams hand held lance mixture or would it burn to hot and burn the tape that attaches it to the stick because i just tested some out in the open and it melted the tar in the ashphalt

[alany]

Lances are ment to burn away their tube as they go, they are generally over-oxidised to burn slow and as a consequence also burn very hot. Consuming the few flimsy turns of paper is a cinch for the sizzling hot dross bubbling with oxygen. Shimizu mentions melting Platinum with such a mixture. This is also how organically fuelled nitrate lance compositions can produce vivid colours.

Melting asphalt is not really impressive for most pyrotechnic composition flame temperatures, its softening range is about 120-150 C, temperatures at which paper will only just begin to char at.

Dan Williams' super sparklers are taped to their sticks for their entire overlapping length so it shouldn't be a problem. Personally I wouldn't implement the handle like that, I'd add a cardboard or timber handle to the butt-end so nothing sticks out beyond the burning end to interfere with dross clearing. I frequently charge lances only partially full then block up the remaining space with paper wadding to make a handle, that's how I make all my portfires.

The sparkler composition he is using is not a traditional lance comp, but a falls lance one, it burns fairly fast actually and is quite oxygen negative. Because of its high conductivity and perchlorate oxidiser it needs a lot of heat to ignite it. I am unsure if a traditional portfire composition will ignite it, but my guess is that it would, the dross from BP-portfire composition is *hot* and will melt though steel if given a chance. I've used something fairly similar to ignite Golden Wave #2, but it is /much/ easier to ignite as it contains sulfur and is nitrate oxidised. Adding a little Aluminium or Magnalium to the prime should solve any ignition problems, or step priming if it is really stubborn.

[fishy1]

i made some today, they are great.