152 replies to this topic

[Pyromaster2003]

You tryed looking on online art shops? I have found a few places which sell it online in the past.

[Chaz]

a2wpyro, got it yet?

Its been a while, why no updates?

Have you got it yet?

[tajmiester]

The problem with 'homemade visco' is it defeats one of the main temptations of the real stuff; the reliable burn rate. Air pockets etc where the paste shrinks as it dries can make it act almost like quickmatch!

Tris

[BurlHorse]

Has anyone tried to make "Homemade Visco" by injecting BP paste into a hollow-cored string using a hobby syringe? And if so, was it successful? (burn rate etc.)

I was thinking of giving this a go but can't find any hollow cored string!

Pardon my poking in my 2 cents, ( Er....Pence? ) but I would think that you would be much more successsful in making small diameter black match and then coating that with N/C Laquer, then whatever suitable finish you like. Seems a bit easier than trying to find Hollow String, though I'm sure it exists.

Regards, Stay Green,

Bear

[tajmiester]

The main problem with blackmatch is that it burns with a HUGE amount of side spit and the composition (bp) is on the outside. This means that sparks can and DO jump sections of blackmatch maybe 1 - 1 1/2" long making an unreliable and possibly dangerous fuse. I saw a video a while back where someone used a few inches of blackmatch to ignite a sample of bp only to see it a spark skip the entire fuse and ignite the comp instantaneously. It can be used safely but you need to use 1.5x the amount you need just incase which is not very ecconomical but then again at ?4.50 a metre viscos not exactly either!

Tris

[Chaz]

I envy the americans so much. They can get visco easily, and for 100ft for about ?15! I reckon none of my rockets have worked because the nozzle was too big (about 6.5mm). I would have made it smaller but I cant ignite it safely and reliably with a fuse smaller than 6mm. My thinner fuse (about 2mm) is drying at the moment, I'll try it tomorrow, but I doubt itll be any good.

I cant make salutes either, because the fuse hole is too big. Maybe FP will be better for the job.

I WANT VISCO! *cries*

[a2wpyro]

yeah i have got it sorry for not speaking

[alany]

If your blackmatch is good enough you try wind a spiral of cotton thread over it, preferabably once in one direction, once in the reverse sense to lock it. That forms a kind of pseudo-visco that can be lacquered if you want it water-proofed.

It is also not unlike how real visco is made, they just spin it with finer threads and more of them in parallel for each layer. I've got some pictures of a visco machine, I've been slowly working on making my own. Unlike some kinds of blasting fuse the casing isn't braided, it is just wrapped, I had a friend in the US do an autopsy of a piece of visco to confirm its internal construction.

http://nexus.cable.n.../visco-machine/
http://nexus.cable.n...viscovitals.jpg

The core thread(s) are moistened and pulled damp through a hopper of /dry/ fuse composition powder is almost all brands, very few apply it as a slurry. I found that rather suprising! Next a layer of up to 12 parallel fine threads are spun over the powder train and core threads. Next another layer of thicker yarns are spun in the opposite direction. If the fuse is to be lacquered it is then run through a bath of coloured lacquer and dried in a heated tunnel before being spooled up ready for sale.

Wrapping blackmatch by hand is a royal pain, I've done it a few times, and I'd never bother again. Chinese cracker fuse is easier to make and performs about the same if made well. The paper coating offers some moisture protection and it can be lacquered to become fully water-proof. You have to be cautious though, chinese fuse can skip, jump, and holdfire if the powder train isn't done properly. I 've used a paste of meal and NC lacquer in chinese fuse, which works great, but means you have to wrap it up quickly before it dries, and you usually get the paste all over your fingers. The acetone isn't great for your skin, and the dried paste is very hard to get off compared to straight meal dust.

[tajmiester]

Yep, Ive got a book called 'cornish explosives' thats got a fairly comprehensive diagram of a bickford safety fuse machine. I am also considering making some sort of simplified version. The tricky bit as it seems to me would be making sure enough bp stuck to the initial threads and didn't fall off before or while they were being wrapped with the outer layers of yarn.

One question though, I was confused when you spoke of 'parallel' threads being spun? Surely if the threads are spun around the core they are nolonger parallel with it?

Tris

Edited by tajmiester, 11 January 2004 - 09:01 AM.

[alany]

Multiple yarns are laid down in parallel with each other, coiled around the core. This means they don't need such a shallow pitch and the machine can run much faster. It is in principle possible to use only one yarn per layer, but the winding pitch would be much more shallow and as a consequence the machine would have to run at higher speed and tension.

Take a look at the picture I posted the URL to, it shows the layers peeled off. Relative to the core yarns the outer casing yarns are orthorgonal (but obviously coil around in the Z direction), and are mutually parallel to each other.

[Chaz]

yeah i have got it sorry for not speaking

Great! Is it any good? Proper visco, not some other type? Is your 'contact' willing to sell to any of us? I would be extremely happy to buy some, how much did he sell it for you anyway?

15m for ??

Bagsie I get the next sale from him!

BTW peeps: I tried my new blackmatch, and it burns through a 4.5mm hole However for some reason I'm still getting beads of moulten BP rolling around over the fuse, even though my BP burning on its own doesnt do that any more (after a thorough milling).

"Visco?, every little helps!"

[The_Djinn]

Chaz, I was told ?5 per m.
Expensive but if you have no other source then some people are willing to pay anything.. unfortunately some people will take advantage of this fact.

Before anyone gets upset, the previous comment was not aimed at anyone in particular in the forum but it is a general fact.
Personaly if I had access to something that others were having a problem getting I would try and assist without bumping up the price for a tidy profit as I am not in this to make money.
In some cases it makes sense if someone has built up a relationship with a supplier, why have it spoiled by requests from a load of other people as a supplier may clamp down on who he supplies all together.

Mark

Edited by The_Djinn, 11 January 2004 - 11:23 AM.

[Chaz]

You really think a2wpyro has just spent ?75 on fuse? Your joking, surely.

* * * * * sells visco for ?5/meter, and a2wpyro didnt buy from * * * * *

?5/Meter is an insane ripoff, its unbelievable. With any luck whoever a2wpyro bought it off isnt charging that much. Lets just be patient and wait for his reply.

Edited by adamw, 11 January 2004 - 12:30 PM.

[adamw]

We arent here to slag anybody off, and trust me, it wont happen, so watch what you say!

My thoughts on this matter are that the more expensive the fuse is, the less people want to use it, so the more unsafe the hobby becomes - ie at say ?10 per meter for example, you dont want to use much of it on just one device, naturally. This gives you a shorter delay and therefore a larger risk...

[Matt]

Why cant people just learn to make blackmatch!!!!!!!! Surely most of you arent making something that absolutley requires visco for it to work. A few may do but not all! tut tut, where HAS the discipline gone.....

-Matt