64 replies to this topic

[mrpyromx]

Ok question. When I make my blackmatch and quickmatch I use GOEX 4F BP because my home made bp is just not quite right. its great for e-matches and breaking shells but for any type of wick its garbage.

now my question is: Just recently I made up a bunch of blackmatch getting things ready to have on hand for the holidays and was testing a short 8 inch peice. as soon as it lit (with very little effort) it was gone. How can I slow this down without getting spitting and spuddering?

[Rhodri]

Hi Mrpyromx

Are you using dextrin as a binder? If so how much (%)? Was the black match confined?

[Matt]

how are you applying the blackpowder? Once upon a time when I was starting out *shudders* I thought I could make fuse by coating string in pva then swirling it in 4f BP. When lit it went up as fast as the BP itself. Im guessing this is how your approaching it also?

There are a few pages on black match manufacture floating around . Heck even I got one

-Matt

Edited by Matt, 23 March 2004 - 09:01 AM.

[Pazza]

If you want to slow it down, use slower BP, I think you can even use greenmix (ie unmilled BP) for black match so dont say that your BP is too crappy. Goex is designed for lift, not for making black match.

[mrpyromx]

6tbls of 4F Goex and 1/2tbls dextrin then added cold water till it was a nice medium slurry then soked 3 peices of cotten string tied togather at the ends to make a decent size fuse.
I honestly think it would be to fast to make quickmatch with. I could add a peice of safty fuse to it for a little delay, but I was making it for a finaly rack im working on, but like I said I truly believe its to fast.

[Phoenix]

Adding a little extra charcoal will slow it down without producing excess dross (and avoiding the "spuddering burn"). Only problem is it does make more sparks, which can increase the risk of skipping sections, possibly leaving you worse off than before. Adding extra dextrin will slow it down too, and not make so many drifting sparks. However, it might produce more dross than the charcoal. I'd go with adding some more dextrin and see what happens. This worked quite well for me (although having said that adding extra charcoal didn't really cause a problem with skipping either). I prefer extra dextrin, as it has the added benefit of making the match stronger and easier to handle.

[pyromaniac]

For my black match due to my lack of a ball mill (at the moment..) I use 9 parts bp to 1 part dextrin. Then use 50:50 water to methylated spirits to make a mix about as thick as porridge. But then the bit which I rekon makes a diference is rubbing in the mixture because Ive tried other ways e.g jus havin the string being pulled thorugh a BP paste then through a guide hole and that neva seems to work for me. But once the BP paste has been rubbed in (with protective gloves latex or whatever) it burns better and more consistently.
I think this would be because with powder just on top of the string it burns simply on the top but rubbed in it burns all the way throguh thus creating a slower balckmatch but one that burns more and is less likely to go out.

Just a thought.

pyromaniac

[Steve]

A usefull way of slowing bp fuse and helping the burn is to quickly dip it in a trough of diluted pva glue, it makes a very thin plastic film over the fuse that slows the burn by directing most of the sparks away from the rest of the fuse and also helps protect it from light rain.

Steve

[Phoenix]

I'd been considering trying something very similar, probably spray painting the black match, to reduce its tendancy to quickmatch as soon as it gets into nosing, and to make it more durable. I was thinking of spraying some with silver paint, since that contains alumninium which might add to the burning temperature, but also provide an effective spark barrier. I though this might make it more suitable for fusing cakes, and possibly chinese style roman candles with (ie candles with a fuse down the length, and clay or sawdust between the charges instead of delay comp), plus I like the idea of shiny silver fuses

My last batch of black match came out much crumblier than I would have liked (due to me using crappy dextrin that I though was cooked enough but wasn't) and seems to like quickmatching, but doesn't like being bent or pushed into close fitting fuse holes. Therefore I've just threaded the lot of into pipes, and I'll make another batch of tougher black match to use for delays some time.

[alany]

its tendancy to quickmatch as soon as it gets into nosing

I always thought that was a feature!

[Phoenix]

I suppose it is when you want a quickmatch effect (for which I'd just use uncoated match), but when the nosing is just there to hold the fuse in place it is better if it doesn't reduce the delay too much. Granted, there should be sufficient fuse outside the nosing to provide a good delay anyway, but evey little helps. More importantly, coating it should stop it from skipping too.

[alany]

Does anyone happen to know the composition of commercial fuse powder?

I know goex makes a number of powders for fuse use, I'd be interested to study them.

[Pretty green flames]

This is listed on PFP database as common fuse:

73% KNO3
15.5% C
11.5% S

Maybe this is what you're looking for.

[alany]

This is listed on PFP database as common fuse:

73% KNO3
15.5% C
11.5% S

Maybe this is what you're looking for.

I haven't tried that one yet, thanks.

[Jerronimo]

This is listed on PFP database as common fuse:

73% KNO3
15.5% C
11.5% S

Maybe this is what you're looking for.

This composition is very close to the common black powder formula, don't expect a huge difference if any....