Visco priming

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Aardvark
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Visco priming

Post by Aardvark »

In this case, for bombettes/cake inserts.

I plan to dip in NC lacquer then in bp+dextrin meal. Just wondering if anyone has any experience with this method? I don't see why it wouldn't work.

Cheers folks,

Sam.
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

The method works but can be unreliable, if you want to make an insert then you will need some sort of rising effect otherwise there going to be a little boring.
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Aardvark
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Re: Visco priming

Post by Aardvark »

Hmmm.. I'm going to have a go at a TT tail. Would the comp need to be wetted slightly? Or can I go ahead and just consolidate around the fuse?

Cheers bud,

Sam.
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

How to make an insert.
1. First ram a clay plug just as you would normally if making a rocket the plug needs to be around 10mm deep.
2. Now take a piece of 3mm visco around 25mm long take one end and put a bend in it so that it will sit inside the void left at the bottom of the tube.
3. Now make a star composition up of your choice a metallic fuelled works best make sure the composition is well integrated next mist spray the composition so it will just hold a shape.
4. Now take your tube and press the bottom end in to the composition hard you should now have composition visco clay plug, set aside to dry.
5. Next is to fill the tube with micro stars/ burst charge/whatever you think will work? Now cap off the top of the tube with a paper cap or damp clay.
6. Next job is dip the base into some nitro and granulated BP and allow to dry, you’re done.
7. Changing the depth of the clay plug will affect the timing it’s not as precise as time fuse but the inserts work very well.
My advice would be to use our ½ inch insert tubes there 63.5 mm long and fit perfect in the ¾ inch tubes, the insert tubes have a slightly thinner wall than a standard ½ rocket tube I think there is 1,600 in stock, if you need a tool to make the insert I can do that for, you will also need to make some micro stars I have formulas for these as well.
Tyvole
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Re: Visco priming

Post by Tyvole »

I have tried primed visco only a couple of times. Once, it worked, the other it didn't. PG's method sounds like a much safer bet and more interesting to boot. Alternatively, you could try out a spollette-based approach. Of course, whatever method you settle on, you'll need to do some height and burn-rate tests first to get the timing right. For cake inserts that won't be launched very high (relative to shells), you won't have much margin for error and the method must be reliably repeatable. Spollettes would be quite short and the timing of them depends a lot on consistent ramming, so PG's technique sounds favourite to me.
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Tyvole
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Re: Visco priming

Post by Tyvole »

As an afterthought, if you use PG's method with a TT-type mix, you probably won't need to prime anything as it lights so readily.
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

This is the great thing with a tool all the work is done for you regarding timing, the rising tail can be more or less what you want silver gold reds blues greens,
Using the Veline formulas damp pressed in to the void give’s a very nice timing 50-60 feet, also the pass fire from the Visco works every time.
Sounds like a little project for you Alan.
Tyvole
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Re: Visco priming

Post by Tyvole »

Pyro-Gear wrote:Sounds like a little project for you Alan.
Oh, like I need yet another project!! Don't worry, this one got me hooked the first time you described it! :-)
Shells are great, but I quite like the shock-effect of mines and somewhat gentler, low-altitude effects too. They somehow seem more immediate and draw some interesting reactions from the audience. The inserts you describe fit the bill perfectly. As a plus, it's easy to use multiples of small effects to create a bigger impression. What I haven't got into yet are fountains. Maybe now I have a press I'll have a go.
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Aardvark
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Re: Visco priming

Post by Aardvark »

I've used a similar method Ken. After looking at how a few commercial inserts are made, I've made a tool that simply put, is a dowel with a 3mm hole down the centre, attached to a base. Allows me to press clay/effect around the fuse without the need for drilling. Works very well! Gives me a nice, repeatable delay and a lovely effect. Thanks bud :)
GalFisk
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Re: Visco priming

Post by GalFisk »

I know I'm replying to an old post, but anyway:
Priming anything with a layer of pure NC lacquer, however thin, is not a good idea. It does not burn vigorously enough, and may easily be blown blind. Always mix a good bit of BP directly into any NC used as prime, and dip the fuses or whatever into this slurry. Then dip the primed end in dry BP for an even more reliable result.
Other primes can be used as well, if BP is undesired.
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

You may have missed this 6. Next job is dip the base into some nitro and granulated BP and allow to dry, you’re done.
Welcome to the forum GalFisk have a seat ;)
Starfire
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Re: Visco priming

Post by Starfire »

Welcome,GalFisk good to see new members posting
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

it’s good to see anyone posting, but I figure due to the current climate the hobby is in a big recession.
Jme86
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Re: Visco priming

Post by Jme86 »

I think it's a bit too close to Christmas to be thinking of pyro but new year I get a chance to set some off :lol:

I did receive an order from cooper man! Anyone know rough weight for an 8" she'll and how much lift will be needed I'm guessing it's gonna weigh just over a kilogram!

Thanks James
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

Well you’re going to need some pretty course BP for that 8 inch and defiantly avoid the 10% by weight I would drop down to around 6% but this would be dependent on how good your BP is, so may I ask what nitrate you are using and the charcoal being used, we don’t want an 8 bursting at ground zero.
Jme86
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Re: Visco priming

Post by Jme86 »

Majority of my chems are from ob, to be honest I've only just perfected my bp! I wasn't drying the nitrate! I recently fired a 4" she'll with it no problem at all! It was meant to be a heart shape but that went a bit wrong! I can post a vid if you like nothing special though!

I did some research but couldn't find allot just that over 6" to use more course bp and avoid 10% just as you said in reply! But I couldn't find an exact percentage!

Thanks James
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richardh08
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Re: Visco priming

Post by richardh08 »

I believe an old rule was 'one ounce per pound' - which is 1/16th.
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

Agreed that’s a good rule of thumb Richard that has stood the test of time
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

Jme86 wrote:Majority of my chems are from ob, to be honest I've only just perfected my bp! I wasn't drying the nitrate! I recently fired a 4" she'll with it no problem at all! It was meant to be a heart shape but that went a bit wrong! I can post a vid if you like nothing special though!

I did some research but couldn't find allot just that over 6" to use more course bp and avoid 10% just as you said in reply! But I couldn't find an exact percentage!

Thanks James
I know Alex well so I would think your charcoal would be pine? If it is then that would give you a mid range performance and given the fact that you have to dry the nitrate I would aim for around 8% of the total weight.

What would be interesting assuming you have time is to show us a burn rate test, take about 5 grams and spread in line on some copy paper this would give us an indication to how good the BP is.

Feel free to show us the heart shell even if never went to plan.
GalFisk
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Re: Visco priming

Post by GalFisk »

Thanks for the welcome. The forum appeared quite dead, but it had some really good and interesting discussions, so I had to join. I was especially impressed with the spectroscopic analysis of the blue formulas.
The problem with dipping the fuse in pure NC is that you create a layer that doesn't pass fire very well. Then you put the BP on the outside of this layer. It mostly works, but I know from personal experience that it sometimes doesn't. Only if the BP is incorporated in the NC beforehand do you have a reliable prime.
Dipping that prime in dry BP helps it take fire even better, and keeps it from smudging other stuff before it's dry.
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Pyro-Gear
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Re: Visco priming

Post by Pyro-Gear »

The forum is only around 15mths old when I created the forum it mainly based around research, I agree the spectrum analysis proved to become very interesting in particular the purity of chemicals, we found high levels of sodium in some per chlorates that upset the blue formulations in particular.

The general situation regarding discussions on UK forums has declined dramatically in 2014 maybe this is due to the new EU regulations controlling critical chemicals that are used in our hobby.

We are lucky regarding our members we have some very astute people on board that have provided some very positive input, personally the forum as a whole has made some inroads to the world of pyrotechnics in its short life hopefully it will continue.

I see your point on the NC dipping a slurry is the best way to go I agree.
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