46 replies to this topic

[littlejohny]

I also have some dope its a slighty syrupy brown liquid, on the back it says "nitrocellulose lacquer". I'll just have to get some model aircraft paper now

[EnigmaticBiker]

I think i know exactly what your talking about, its tissue paper rolled up with meal powder inside very tricky to make i tried it and couldn't get it to roll.

I've got a tested method for producing a reasonably consistent tube fuse. It's very fiddly but works.

Take a 3-5 cm wide strip of greaseproof paper, partially roll it on a knitting needle or similar 3mm smooth rod.
Put on a thin bead of wood glue (white PVA) and roll without getting any on the rod ends. the paper will crease but it should be OK.
Slide off rod, allow to dry, brush with extra glue for strength.
Make a very fine, slow (less KNO3 less S) BP mixture with 5% dextrin, normal BP is WAY TOO FAST.
Make a thick slurry, too thin and it will be patchy, too thick and syringe will block.
Use a small syringe to inject mixture through tube.
Dry carefully and TEST before using.

Hope that helps.

[Rhodri]

Hi All

Another simple fuse can be made out of a plastic drinking straw.

The type is not the large (> 5mm) - ?stripped? plastic straw but the variant found glued to certain paper-carton drinks.

Usually these appear as a single colour or transparent without a 'bendy' piece.

Simply take one of these and ram it into fine BP. Try using an empty film plastic film capsule to hold the BP.

Then consolidate with a used match. Once rammed, top with a small piece of fuse paper - there you go, one very simple and reliable fuse!

Of course, you'd have to make a set of these and time to get the average speed if you plan to use these for timed events.

Just a small environmental caveat - the plastic will give off a small amount of toxic smoke.

Stay safe.

[EnigmaticBiker]

Simply take one of these and ram it into fine BP. Try using an empty film plastic film capsule to hold the BP.

Then consolidate with a used match. Once rammed, top with a small piece of fuse paper - there you go, one very simple and reliable fuse!

Very neat and a lot less fiddling than my method.

The wet method doesn't need fusepaper as I slow the fuse by altering the mix.

Had an amusing incident with mine recently, tried straight BP. I realised there was a miscalculation when a test piece shot up the garden

[Darkstar]

[quote name='EnigmaticBiker' date='Feb 28 2006, 02:27 PM' post='24418']
Very neat and a lot less fiddling than my method.

The wet method doesn't need fusepaper as I slow the fuse by altering the mix.

Or try the cotton bootlace method...? Reasonably waterproof, doesn't loose powder
when cut, flexible, no melted plastic or toxic vapours (the cotton is consumed as the
fuse burns) and as near to homemade visco as you'll get without building a spinning
machine. The soak in shellac solution (in ethanol) consolidates the powder, producing
an even burn rate.

Edited by Darkstar, 28 February 2006 - 04:50 PM.

[adamw]

Remember to always test your fuses before using them on anything energetic!!

(and no smart arses saying that if you test it, you haven't got any left!)

[EnigmaticBiker]

Remember to always test your fuses before using them on anything energetic!!

(and no smart arses saying that if you test it, you haven't got any left!)

A number of my fuses have been more energetic than the things they were attached to.

[phildunford]

In reply to the questions about making black match, I've had complete success with the method I show on my website

thegreenman


I use dextrin to make the BP stick, but have also used starch - some people also use gum arabic.

The most significant change I have made is to use several strands of the thinnest cotton wick I can get, all twised together. The resultant match is stiff, fierce burning and does not untwist.

You can get the cotton wick on spools from candle making suppliers.

[fishy1]

for those of you who don't have a ball mill, i tried an experiment to see how good i could get BP without a mill.

3.25g of a very light special pine charcoal, that you could crush with your fingers, and 3.25g of balsa wood charcoal were used with 5g sulphur and 31g of kno3.

i added a little water, and pestle and mortared it for about 5 mins, until it was smooth. then a pinch of dextrin was added. a little more water was added to get it as even as possible. standard cotton parcel string was dipped in the mixture, and any excess removed. it dryed in 2 days, and burns fiercly and reliably.
it's burn rate is about 2inches per second, so it is quite fast. it will burn through holes that i have to force it into. it's great stuff, and i have 10m of it with the one batch.


the balsa wood was overcooked to a little less kno3 was added to compensate for the ash that i couldn't blow off.

Edited by fishy1, 01 March 2006 - 05:53 PM.

[jcow]

I have made some ok fuses using chlorate that i think are quite safe. i soak kitchen roll in a saturated solution of sodium chlorate and then dry thoroughly.the problem with these fuses is that the chlorate is very hydroscopic, so if the fuse is exposed to humid air for too long, the burning speed is reduced.the speed is about 1-2 inches per second.the fuses burn with a small yellow flame.

shop bought chlorate is only half chlorate, the rest is a fire retardant that i assume is sodium chloride.the chloride crystals are smaller than the chlorate, so a kitchen sieve is used to simply separate the mixture.
if the mixture is not separated, then the fuses will burn much slower and leave loads of chloride residue.

the fuses are a little unpredictable, but i have always used them for improvised bangers and have never had any problems. i find that the finer the paper, the slower the burning speed.

obviously proper potassium nitrate based fusing is much safer and better, but the chlorate fusing is cheap and ideal for fusing small bangers. a website that has now shut down claims you can use rolled chlorate fusing as rocket propellant.

[Pretty green flames]

I have made some ok fuses using chlorate that i think are quite safe. i soak kitchen roll in a saturated solution of sodium chlorate and then dry thoroughly.the problem with these fuses is that the chlorate is very hydroscopic, so if the fuse is exposed to humid air for too long, the burning speed is reduced.the speed is about 1-2 inches per second.the fuses burn with a small yellow flame.

shop bought chlorate is only half chlorate, the rest is a fire retardant that i assume is sodium chloride.the chloride crystals are smaller than the chlorate, so a kitchen sieve is used to simply separate the mixture.
if the mixture is not separated, then the fuses will burn much slower and leave loads of chloride residue.

the fuses are a little unpredictable, but i have always used them for improvised bangers and have never had any problems. i find that the finer the paper, the slower the burning speed.

obviously proper potassium nitrate based fusing is much safer and better, but the chlorate fusing is cheap and ideal for fusing small bangers. a website that has now shut down claims you can use rolled chlorate fusing as rocket propellant.

Sounds a bit kewlish type of fuse to me. First of all chlorate is a very dangerous and unpredictable material. Using it with anything that has traces of sulfur or finely divided metals poses a great risk. So why just not play safe with nitrate based fuses.

[fishy1]

"a little unpredictable"?

not what you want, especially with bangers.
do you wear safety gear lighting them?

[pyrotrev]

The traditional Japanese way of making delay fuse might be of interest to those who have difficulty in getting hold of Visco, PIC or Bickford (why availability of fuse is so carefully controlled is a bit of a mystery to me though - I would have thought it would have been in the interests of hospitals etc. to have small quantities of reliable stuff readily available to stop people having things blow up in their face*).
Step 1) Paste some sheets of thin paper (meant to be thin Kozo paper - but might newspaper work?) with a very fine BP slurry on both sides and dry to make powder pasted paper (PPP). Cut into 250mm x 75mm strips.
2) Sprinkle a strip of PPP with some more finely ground BP (moisten it a bit) tightly and evenly wrap it long edge-wise around a 300mm length of 3mm brass rod or a knitting needle. Then take a 275 x 350mm sheet of paper (again meant to be Kozo, but thin Kraft might do), and wrap it around the PPP core to form an outer cover.
3) Pull the rod/knitting needle out of the middle, holding the loose end to stop the cover paper unwinding. Place the fuse on a flat board, and roll with another bit of flat wood 450 x 100 x >25mm using both hands, until the central hole disappears and the thing takes on the nature of a pencil, only with BP down the middle instead of lead. Paste down the outer edge of paper wrap.
4) Further outer wraps can be added if it's desired to make a rigid fuse with high resistance to communicating fire laterally, wrap, roll until tight then paste down the end.
Methinks this method could be slightly simplified for general purpose fuse (Visco replacement) by taking a 250mm by 400mm is sheet of paper and pasting a 75mm wide strip on one end with powder, then proceeding as per 2), but I haven't tried it.

* it was having to conduct funerals for so many Cornish miners that spurred Bickford to develop his famous fuse.

Edited by pyrotrev, 02 March 2006 - 09:37 PM.

[Plays with Fire]

The traditional Japanese way of making delay fuse might be of interest to those who have difficulty in getting hold of Visco, PIC or Bickford (why availability of fuse is so carefully controlled is a bit of a mystery to me though - I would have thought it would have been in the interests of hospitals etc. to have small quantities of reliable stuff readily available to stop people having things blow up in their face*).
Step 1) Paste some sheets of thin paper (meant to be thin Kozo paper - but might newspaper work?) with a very fine BP slurry on both sides and dry to make powder pasted paper (PPP). Cut into 250mm x 75mm strips.
2) Sprinkle a strip of PPP with some more finely ground BP (moisten it a bit) tightly and evenly wrap it long edge-wise around a 300mm length of 3mm brass rod or a knitting needle. Then take a 275 x 350mm sheet of paper (again meant to be Kozo, but thin Kraft might do), and wrap it around the PPP core to form an outer cover.
3) Pull the rod/knitting needle out of the middle, holding the loose end to stop the cover paper unwinding. Place the fuse on a flat board, and roll with another bit of flat wood 450 x 100 x >25mm using both hands, until the central hole disappears and the thing takes on the nature of a pencil, only with BP down the middle instead of lead. Paste down the outer edge of paper wrap.
4) Further outer wraps can be added if it's desired to make a rigid fuse with high resistance to communicating fire laterally, wrap, roll until tight then paste down the end.
Methinks this method could be slightly simplified for general purpose fuse (Visco replacement) by taking a 250mm by 400mm is sheet of paper and pasting a 75mm wide strip on one end with powder, then proceeding as per 2), but I haven't tried it.

* it was having to conduct funerals for so many Cornish miners that spurred Bickford to develop his famous fuse.

Wow...that seems super complicated! I read it twice, but I'm still unsure of how it's done/what it is. I'm not saying that you were unclear, but maybe I just don't understand. Now I will read it a few more times, just to see if I get it...
-Plays with Fire

[pyrotrev]

Wow...that seems super complicated! I read it twice, but I'm still unsure of how it's done/what it is. I'm not saying that you were unclear, but maybe I just don't understand. Now I will read it a few more times, just to see if I get it...
-Plays with Fire

Yes, it took me a while to appreciate the process from Shimizu San's book too - very inscrutable these Orientals!. Done properly it ought to produce a fuse with a well compacted core, and hence steady burning and no flash-through.