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Sparky

Member Since 03 Dec 2009
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Topics I've Started

Rolling my first ever stars

20 August 2015 - 11:29 PM

Hey all
 
I'm doing a few bits and bobs at the moment and finally I got a chance to test out my new roller and my own skills at rolling stars in a machine (Ken's invention).
 
I have viewed about every tutorial on YouTube I can find, read everything I can find on all the various forums and I thought I had a pretty good handle on the basics and enough to at least make a start. All this has been acquired over the years while not having a rolling machine and I've just been using cut and pumped stars so far. I want to progress to rolled because I can see that the irregular shape of cut stars affects the way they spread and spoils the break on my shells. I also want to be able to use crackle cores and colour changes etc.
 
So I knocked up a batch of Veline Red with about 9% Red Gum and 4% Dextrin. Had my misting spray all primed with 80% water/20%(max) Meths. It's a very similar formula to the one I use for basic cut rubber stars as they are called so I've used it a lot.
 
To make life easier I actually acquired some great little crackle stars which are probably Bismuth trioxide dragons egg with a layer of prime. They are about 1mm in diameter and perfect spheres, not too smooth so should pick up comp well.
 
So I popped a couple of spoonfuls into the roller, got it spinning. Gave them a very accurate and small spray fine mist of water/alc right on to them. Then gently and slowly added some comp directly on to the stars. I waited...waited more...very little pickup at all.
 
I could see they were damp but nothing.... I tried more comp but nothing. I tried more misting but this just ended up making the comp too wet and stick to the drum.
 
I tried more batches and variations on amount of misting...amounts of comp but no luck.
 
I'd really appreciate some tips that I may have overlooked. Other things I've considered are:
 
My comp is supposed to be an easy one to roll with but I have not overly milled the chemicals but they are well integrated. I understood that too fine is harder to roll.
 
The crackle stars should be a good starter and a bit of a cheat.
 
My mister is very fine atomiser type but lacks a bit of accuracy as the spray is quite wide but I get right up close. It delivers a very small amount at a time.
 
I'm not sure if I am using enough cores to start? Does it help to really load up the roller?
 
Is the plastic of the drum too "sticky", I was thinking about an upgrade to a stainless steel bowl I found.
 
Suggestions will be gratefully received.

Gerb tubes

02 August 2015 - 10:57 PM

Hi all

 

I seem to be single handedly dominating all new posts at the moment, apologies lol.

 

Anyway...your wisdom is needed yet again!

 

I have 3/4" gerb tooling which I've been using with great success for a while. I can't remember the nozzle diameter but I remember it being within the usual range recommended for the ID of the gerb. It is closed enough to build up enough pressure to eject the effect a nice height.

I use thick walled spiral wound paper tubes that in their 7 inch form are strong enough for core burning rockets (well usually but I think that's me...see other post) but for gerbs I are 3 1/2" long. This length is perfect for a gerb and the paper does not burn through even with some hotter burning compositions.

 

My problem is that I want the gerbs to last longer but if I use a longer tube I get burn through occurring. Slower burning composition are not what I want and I've been trying to use 7" tubes with basic BP titanium gerb compositions but I get burnthrough.

 

Is there anything you can recommend to help make them more durable? I've seen some articles about using wood hardeners but they seem to be aimed at improving strength for rockets and not durability against burning through. I wondered if there were some fire retarding chemicals I could dip them in etc but that wouldn't influence the firework effect?

Any suggestions? I'm not really up for rolling my own tubes as yet before you make that suggestion  :D


AP oxidised gerbs and lance Formula

30 July 2015 - 12:33 AM

Hi all

 

I'm doing some experimentation with AP based compositions for lancework and gerbs and in some compositions I've seen steel powder added for spark effects. Steel powder is actually quite hard to find and also quite pricey so I was wondering how different iron powder / filings would be in comparison.

Any idea how different the effect would be? Steel only has some added carbon so I can't see how that would drastically affect the effect.

I'm going to give it a try anyway but thought I'd ask what people thought the difference may be. I won;t get the chance to test it with steel.


1lb coreburner tooling for nozzleless hand rammed motors

26 July 2015 - 03:33 PM

Hi all

 

I've been away from the hobby for a little while for no other reason than my many other hobbies got in the way. Anyway I'm back at it again and once again my hand rammed rockets are the bane of my life.

I have some nicely made aluminium tooling and the best concentric, STRONG tubes money can buy but still I have issues with reliability. I won't go into too much detail about my multiple failures and multiple attempts to build a motor I can trust well enough to lift the equivalent header to about a 3 inch size shell or close to that. Strangely when I started out with inferior tubes and chemicals and experience I had greater reliability. All I will say is that over the many attempts I have tried all the obvious tweaks but I still get a significant number failing. Too many to trust putting a header on that is going to break quite hard.

 

The usual failure is the tube splitting but I've had the nozzle blow out and occasionally the bulkhead.

I've not given up and I will go back to basics with my ramming techniques, compositions, construction etc so I'm not seeking more advice there yet. One thing I wanted to try though but wanted opinions and advice on are nozzleless rockets but using tooling designed for a nozzled coreburner. From what I understand I could achieve this by using as hot a BP fuel mix as I can and ramming them just the same but without the clay nozzle.

Is that really all there is to it? I was going to give it a go and I wondered if this method might be more forgiving and reliable for someone who clearly needs to work on their nozzled core burners lol.

p.s. I would like to make a press but until I have more workshop space it's the one thing I am going to have to wait a bit longer for unfortunately.
 


Wood meal

19 July 2015 - 12:17 PM

Hi all

 

I have tons of sawdust but I'm not having much success making wood meal with it. Any suggestions on the best way of making your own?

 

Cheers