14 replies to this topic

[jsoh019]

I am building a visco machine but i have no idea what coating to use on the fuse
I know its NC lacquer but I hear that srinking dope and some sort of dye can be added , Where can u buy shrinking dope in the UK and what kind of dye is used?
I also hear that NC lacquer can be made, does anyone know how?
I also have a spray can of car cellulose lacquer, is this the right stuff?

[T-sec]

Any experience in making a visco machine in don't have, because it's to easy and cheap to buy per roll.
But getting nitrocellulose is not te heavy.
I use the pyrodex flakes wich you can buy as smokeless shooting gun powder, or collect from blank cartridges wich are used with P.A.K. guns etc. Add 10% with acceton/ether fluid, and you got your self a liquid nitrolacker.

[pymp]

I think what you have in the spray can is NC lacquer, as I have heard it mentioned that you can get it in spray or bottled form from car repair shops. Similarly, you can get sprays of it for repairing surface damage to old guitars.

[jsoh019]

Ok so the car stuff is ok. What about shinking dope? Would cellulose shrinking dope work, if there is such a thing

[EnigmaticBiker]

I know its NC lacquer but I hear that srinking dope and some sort of dye can be added , Where can u buy shrinking dope in the UK and what kind of dye is used?
I also hear that NC lacquer can be made, does anyone know how?
I also have a spray can of car cellulose lacquer, is this the right stuff?

I got my NC laquer from ebay via a company called "Five star adhesives".

http://stores.ebay.c...7QQftidZ2QQtZkm

or email them at info@glue-shop.com

Cheap too

or you could try googling Nitrate dope, shrinking dope or similar, if you specifically want NC (Cellulose acetate can also be sold as "dope").

Thin with acetone (propanone), MEK, amyl acetate or similar solvent as it is quite viscous.

Edited by EnigmaticBiker, 18 November 2006 - 12:43 PM.

[JamesH]

I have seen different types of nitrate dope available with various shrinking properties such as non taut, low taut and high taut.
Is there a preference for any particular type for pyrotechnic applications?

[EnigmaticBiker]

I have seen different types of nitrate dope available with various shrinking properties such as non taut, low taut and high taut.
Is there a preference for any particular type for pyrotechnic applications?

Not sure, I've used the type I mentioned above for crackling microstars, sucessfully.

Assuming that the Nitrocellulose content is what causes shrinkage, I would have thought that the greater the proportion of NC in it, the greater the shrinkage.

Curiously, my sample ("Nitrate dope, traditional formula") claims it contains cellulose acetate and I find via wikipedia that the acetate has been used since before the first world war as "dope" for aircraft wing fabric and x - ray film from 1934.

How much of a laquer is actually NC is debateable.

[Mumbles]

One normal doping agent is camphor. It increases it's plasticity reducing cracking specifically when the fuse is bent and such. I'm not sure if this is the same as an antishrinking dope. For dye, I think something as simple as food coloring works just fine. Dye isn't really neccesary though. I've also heard of people using ping pong balls. They will already have the camphor added. Camphor Oil is not camphor by the way, nor is there actually any camphor in it.

I can provide a synth for NC, but I want to have moderator/admin approval. It is technically a high explosive afterall. The synth is fairly easy as far as syntheses go, but it does of course come with it's inherent dangers.


Pyrodex isn't nitrocellulose based by the way, just FYI. It is Perchlorate based I do believe actually.

Edited by Mumbles, 21 November 2006 - 09:08 PM.

[BrightStar]

I've also heard of people using ping pong balls. They will already have the camphor added.

This method is worth trying and very cheap - you can make half a litre for GBP £3.50. I add 65ml of acetone to one shredded ping pong ball (about 2.7g) in a small jar and just leave it for a few hours, shaking from time to time. When done, you have 5% NC lacquer. There is some insoluble filler that precipitates out at the bottom of the jar but it doesn't seem to matter. I have been using orange coloured ping pong balls recently, giving a nice light orange translucent lacquer

Using it as a binder, the trick is to use a minimum amount of lacquer and keep it well thinned. It sticks comps together remarkably well when used sparingly. The dried lacquer is quite flexible - perhaps due to the camphor, and IMHO would be fine for coating visco.

[jsoh019]

Ok thanks guys for the info, I will see what I can find

[leosedf]

What if we use Aqueous solution of polyvinyl butyral instead of NC?
Details can be found HERE and HERE .
Seems fine to me

[EnigmaticBiker]

Wouldn't drying be a problem with water based resins, polyvinyl butyral seems a lot like PVA/EVA white glue emulsions.

I'm not saying it wouldn't work though.

Edited by EnigmaticBiker, 27 November 2006 - 10:52 AM.

[leosedf]

Yes, but homemade visco has only BP i think.

Edited by leosedf, 27 November 2006 - 10:51 AM.

[Mumbles]

I would be worried about the waterbased resin leeching KNO3 out of the core into the resin soln itself, or into the string coating. I feel this has the potential to compromise the integrity of the fuse. It could potentially lead to hang firing, fuse going out, etc. All in all unreliable fuse.

Edited by Mumbles, 27 November 2006 - 08:51 PM.

[leosedf]

Since i have a sample of this here it doesn't seem it will happen.
It's thick and dries fast.