That PVB blue.

[Adr2412]

What is the interesting crosslinker at room temperature. Phenolic I use is hexamine free. But I soften the parlon as well by using a solvent blend. It gives thar extra bit of solidity and provides more chlorine intik
macy.

[Pyro-Gear]

Well if you soften the Parlon and activate the PVB you’re getting nothing from the cross-linking of the phenolic other than an addition as a fuel additive, trust me I have worked on this for years.
Cross-linking can be done on the phenolic at room temperature, however, I am not at liberty to say how at the moment.
Hexamine will cross-link but at very dangerous temperatures.

Here is a test for you, take a small amount of phenolic add acetic acid at 5% ,,, to you white vinegar make a paste and set to the side and watch it set …WARNING DO NOT USE THIS IN A COMPOSITION for test purpose only.

[Adr2412]

It very clear to me that adding any amount of mild acid can be dangerous in the presence of highlt reactice metals and powerfull oxidisers. In all honesty it would be interesting to know but I imagine that stars cured this way would be somewhat troublesome to prime. Today it is already challenging to get the star surface to start meltin.

[Adr2412]

Your statement has triggered my curiosity. A quick google search has revealed various acids which can be catayste
s to phenolic resin curing. Ar some point it might be interesting to look into this as well. In si far my results the way I operarw are very encouraging.

[Adr2412]

I have never ever tried phenolic resin on its own as a binder. Surely though in conjunction with PVB it is giving me excellent results. Stars are rock solid, burn is super clean and the colours simply awesome. Over the past summer I have done trials with Phenolic resin as a fuel in conjunction with dextrin as a replacement for redgum in the classical Red Gum / Magnalium / dextrin stars. One thing which was not immediately apparent before is that Phenolic resin at least the one I have (Nitroparis) immediately dissolves in a 50/50 mixture of water and ethanol. ON top of that the resulting stars are definitely way much harder than had the dextrin only be used. They are very hard and reliable and roll just excellently.

[Pyro-Gear]

It was around 6 years ago when I first imported phenolic resin from Nitro Paris and started to conduct some tests on various known formula’s, the Veline system was my main target.
I removed any Dextrin plus red gum and rebalanced the formula using phenolic resin as the binder, I used 75% alcohol /water mix, the results showed promise but I found that the stars tend to be driven in if the temperature was too high.

Next I tried phenolic that I was given by a Chinese factory, this came in lump form and I was advised to use pure alcohol (well as near as I could get) after crushing and milling I more or less had the same product as nitro Paris and the performance was identical with 75/25 alcohol but a vast improvement with pure alcohol.

I then looked in to the properties of PVB and imported some from Germany( I suspect you do to) from 2014 I spent a lot of time developing formulations for colour and some strobe comp’s I released some of the information to a Maltese club in late 2014 and as far as I know they ran some tests and liked the results.

In 2015 I published all my work in AFN viewtopic.php?f=17&t=1199 which appeared in the January 2016 issue.

Now it would be interesting to see how your stars perform against mine, for now I am working on lance work for another Maltase club, best regards Ken.

[Adr2412]

Our experience with PR and PVB started way back in 2013. The advantage of the combination was more than appreciable mainly due to three key factors 1) Clean and Bright burn 2)lowered ignition point and Larger flame envelope and 3) Rock solid stars when done properly. The last part took a bit more work also because the amount of PVB we where using initially was simply not enough. I have had a good look at your formulations, the ones published in the AFN paper. My present formulation set is significantly different using way less parlon (-4 to 5 pc Blue and purple being an exception ) and magnalium (-7pc and more) to and putting more reliance on phenolic resin. I believe you are loosing a lot by not using PR as an accessory fuel but perhaps you relied on a lot more parlon so as to be able to have acetone cut stars in which case your. Also 2pc PVB (some of your stars have this much) might be enough binder for a single shot comet or a rolled star but it will not do the tricks for a three stage cylindrical shell. I have a complete rainbow colour set with Red, Red Orange, Soft Orange, Yellow, Lime Yellow , Green , Turquoise, Blue, Purple, Fuschia, White and Silver specially formulated for the Maltese multi break shell. They still need some further tweaks for ultimate perfection but are fairly there. All burn rate matched so that they can be used in the same petal without troubles.

I have still only one unknown when working up this system. in the yellow I have been using Barium Nitrate and Sodium OXalate. In the first year it worked great with no troubles so no double substitution reaction in between BArium Nitrate and Sodium Oxalate. The yellow was just simply impressive no orangy tinge at all. However after that in some batches not all I started having the conversion to sodium nitrate, which with Maltas humidity is a nightmare. I believe the level of humidity in Sodium Oxalate at mixing stage has a role to play in this. Else it could be that I had insufficient wetting in some batches which made them more permeable to atmospheric humidity which I imagine to facilitate further the double substitution reaction. Now I have switched it the Oxalate to Cryolite and is pending some aerial testing.

[sambo]

I've found calcium carbonate works will with Barium Nitrate for yellow, you could try this in place of the sodium oxalate.

[Adr2412]

Yes that is also an option thanks for the advise. On some ground tests we did cryolite seems more of the yellow we are after. This week we should be firing the shells and will see how it is up in the skies.

[Lloyd]

Adr,
I'm so averse to 'sodium yellow', I'll go to any lengths to avoid it. To that end, mixtures of barium green and strontium red permit one to achieve any color from green to yellow to orange to red, just by varying the percentage of each.

To accomplish it, simply make compositions with one then the other oxidizer, each of which burns at the desired rate.

You can then mix them in various proportions to achieve the different colors, with no change in speed of burn.

Lloyd

[Adr2412]

lloyd we definitely share the same aversion. If there is a colour I literally hate in pyro is the Sodium "amber" emission of the older yellow chlorate formula. However I find yellows with Barium Nitrate and Sodium quite appeasing and definitely away from the dirty orange spectrum of the older compositions. I based my yellow on one of the many Barium Nitrate / Perchlorate / Barium Carbonate / Parlon / Magnalium / redgum / Dextrin . Obviously done using Phenolic resin and PVB. The technique effectively is based on switchins a part of the BArium Carbonate typically 6.5 to 7 pc of the full composition to Sodium Oxalate or Cryolite. Adjusting the ratio of Barium Carbonate to Cryolite / Sodium Oxalate allow for the creation of any shadow of yellow one desires from the deep gold thinged to lemony to lime. I am pretty sure (although never tested) that the same can be done also using calcium carbonate / and strontium carbonate albeit I would imagine that the yellow colour output would be more sensitive to smaller quantities of the chemicals given the spectral emissions of Strontium and Calcium are further down the visible spectrum range. At the end it's all around physics of light.

[richardh08]

Adrian makes a valid point.

As should be apparent from the attached chromaticity diagram, on which I have marked some of the significant emitters, a mix of Ba and Sr compounds can produce any intermediate colour that, to the eye, is indistinguishable from the corresponding pure spectral emission. And that includes Na yellow!

Conversely, a mix of Ba and Na can produce any intermediate colour which, to the eye, will be indistinguishable from the colour made from an appropriate mix of Ba and Sr.

A composition that contains a sodium compound doesn't necessarily produce the 'hated' Na yellow.

[Pyro-Gear]

Well I like my phenolic yellow https://www.youtube.com/watch?v=GJuPP0mtTkQ
Using PVB only and rolled with a blue this happens https://www.youtube.com/watch?v=aqG2RjRQZ5I old camera but you get my point.

[Adr2412]

[img][http://www.pyrobin.com/files/28378212_1 ... 0363_n.jpg]

This is my result so far with PR and PVB. I Chose this as it shows the main colours and is fairly true to actual performance although as always cameras rarely do any justice to the true life experience.

[Adr2412]

Well I like my phenolic yellow https://www.youtube.com/watch?v=GJuPP0mtTkQ
Using PVB only and rolled with a blue this happens https://www.youtube.com/watch?v=aqG2RjRQZ5I old camera but you get my point.

The jetting effect is probably happening due to uneven ignition of the yellow star. This technique can be used to create an effect using a vivid fast burning star formula. it creates sort of swimming stars.

[Pyro-Gear]

Cheers for the input, but I know why and how that’s what I wanted, fun aren’t they.

[Sulphurstan]

Old thread, but interesting to me for my actual experiments...
I'm trying to make go getters, but blue!
Until now, by modifying the united nuclear receipt (addin Cu salts..) the go getter fly, but White!!
I was thinking to take this pvb blue composition, and make it hotter, by substituting part of the fuel with K Benzoate.. Does that makes sense or not?
Thank you in advance.

[Lloyd]

The 'master' go-getter maker is John Driver. Look up his formulae.

Lloyd

[Pyro-Gear]

Trying to hot up the PVB blue will result in a whiteout your best bet is to go to an ammonium perchlorate based composition IE:
ammonium perchlorate 50
Copper carbonate 15
aluminium 325# 10
PVC or Parlon 25.

[Sulphurstan]

Yep. I tried AP in go getter s, but with another composition (AP, CuBenzo, Hexamine), and it always cato-ed (like too reactive, and self-contained???), But as a star, wouhaaa, a real AP blue!

I thank you for this formula and will give it a try with this one here, and let you know.
Just to make sure Al is atomized or flaky? Guess with this mesh, it can only be atomized, right?

[Sulphurstan]

Maybe a silly question: can this comp be sieved for intimate mixing? I would never sieve KP and 325 Al, but AP, is it ok?

[Lloyd]

If dampened before screening, most compositions are pretty docile, and safely screened (even some pretty 'hot' flash mixtures). I would screen the dry ingredients individually, before mixing and dampening.

Lloyd

[Sulphurstan]

Ok, just done and put into small tubes with a hollow core, they are drying at the moment.... Hope these little go getters will lift off, and blue!
I tried a small pile of this mix, before dampening with acetone, and burn rate was pretty slow.... Should I have better used flaky Al instead of spherical atomized 325 Al?
Well, will see in a few days, once dry

[Pyro-Gear]

Just a little advice, make sure your match is KP as AP has a dislike for nitrates.
Atomised aluminum will be fine.

[Sulphurstan]

Ok, so test has been made with this AP Al CuCO3 mix. The go-getter tubes are ID 10 mm, length 50 mm, the hollow core is Diam 3mm, ignition at the upper end of the core (near the end plug).
It lifted off, but only 3 meters, and then falled on the ground continuing burning. (But nice color by the way).
3 causes: they were not fully dried OR there's not enough pressure in the exhaust gases OR the fuel is not hot enough.
I was thinking of creating more pressure at exhaust by producing even more gaseous products, replacing part of the Al with either:
-CuBenzo
-Hexamine (but is it compatible with Al??)
Or a mix of these 2?
Do you think, that could work, and, if yes, how much Al out, for how much CuB or Hexamine in???

Another idea, would be to replace part of the Spherical Al with Al bronze, which is more reactive?

Any thoughts welcomed!

[Pyro]

I would guess using novolac instead of aluminium and black copper oxide instead of the carbonate would give you the thrust you need if a core is used in traditional Go-Getter fashion. That composition with titanium added is used for indoor fountains and they burn very well.

[Pyro-Gear]

Ammonium Perchlorate_____50%

Copper Oxychloride________15%

Aluminum ( Fine atomized ) 7%

Hexamine __________________3%

Rosin or Vinsol _____________5%

Parlon_____________________20%

Try that!

[Sulphurstan]

Thanks to Both of you!!
My most humble apologies!
I was too impatient!
One day more drying, and"pfffffuitttt", lift off like hell!

Sorry again.

If moderators permit, I'll start a new thread called go getter and put Ken's formula AP, Al, CuCo3, Parlon as it is for blue G-G. Works perfectly (still, will test a few more to make sure, it's reliable as G-G, 100% success).

Anyway, I'll consider the help you sent me, to "pimp them up"s little bit, in order to put a little bit more weight with a little report on top.

[Pyro-Gear]

I have to say I was a little surprised at the initial failure, however drying times from my own experience would require at least 4 days, feel free to open a new thread on the subject any input is welcome.