Whistling Bottle Rockets and Fuel Preparation

[Falcon2]

Hi Everyone,

 

Sorry to start another thread on whistle rockets, but after quite some time searching I've run into some problems, which need answers.

 

Can someone please outline very specifically the process by which the vaseline, catalyst and benzoate (in my case) are mixed with the oxidiser. I've seen a number of posts relating to just mixing all the chemicals after milling separately, adding the vaseline in solvent and then rubbing it together very well.

 

It seems that the inherent danger of making whistle mix that this is not a safe as possible operation, and then theres the preparation description on skylighters page which calls for catalyst and benzoate(in my case), mixed with the vaseline in solvent and then slowing adding the oxidiser to the wetted mix.

 

Could you please advise on the safest possible operation.

 

One other thing it has been mentioned previously as to the use of bottle rocket tooling for making whistling bottle rockets. I have the BR tooling from wolter so is this suitable.

Since I am unable to get perchlorate where I am is it possible to replace this with some high grade KClO3. Another problem I have is forgeting to order Iron Oxide with my previous order so would a black copper oxide catalyst suffice. Unfortunately I haven't got access to whitchty site, its blocked by company policy for some unknown reason.

 

Sorry for another question but having both potassium and sodium benzoate which is the best / easiest / safest one to use first.

Just recapping I wish to use a KCLO3 / K or Na Benzoate / Vase / CuO

Any ideas on the ratios or will it be a standard 70:30 or 76:23

 

Thankyou very much!

Edited September 14, 2011 by Falcon2

[dagabu]

I have not and do not know if you can use chlorate for whistle fuel. Perhaps someone else here could answer answer that question better then I.

 

I can however answer some of the other parts. If you are in the USA, you can order Perc for about $5.00 a pound. You can order Red Iron Oxide from pottery shops for less then what it sells for at pyro shops. I mill my benzoate and catalyst together, spray a 1:2 mix of mineral oil and camping gas on the heap until I have 4% mineral oil. I then fold in the perc and screen it a few times to mix it them rice it through a 8 mesh screen.

 

If you use petroleum jelly, you need to melt it and then mix in camping gas to make a liquid. I think this is dangerous and stupid. Side by side whistle rockets (1-mineral oil, 1-petroleum jelly) at Mason City in a drag race showed no difference in lifting a salute heading on the same size rocket.

 

"Sodium benzoate is very much more hygroscopic than potassium benzoate."

LINK

 

There is no noticeable difference in safety between the two benzoates that I know of and I mix them in a very standard 70:30:1:4 ratio. I have not tried the 76:23 mix.

 

-dag

[r1dermon]

has anyone pressed whistle fuel dry?

 

 

[bonkers]

The way i have mixed it for some time now has always been the same:

I melt vaseline and thinner, then adding the catalyst and fuel. After this I mix in the oxidizer very wel, until the entire mix is equal in color. I make sure that every chemical is finer than 120 mesh before mixing.

 

Using the chlorate composition has proven more unstable than the perchlorate version so that's not advised to use.

I have had no problem using petroleum jelly and thinner and will keep using that method, I keep temperatures below 40°C when adding the mix.

Since the entire mix is wet i find it rather safe to add the oxidizer.

 

If you can, try comparing the sodium salycilate version with the benzoate version, the results are not mind blowing but the difference is obvious.

Also, try to make sure you are using quality red iron oxide, quality's may influence results. Black copper oxide may work but not as good as red oxide.

Whitchty found that black copper oxide only increases thrust when using sodium benzoate.

I also use copperoxychloride for the core and iron oxide in the upper part, it increases thrust noticeably.

 

Keep in mind that making whistle rockets is not done whithout a decent press and protection (I use steel blast shield with mirror on backside) and the right tools.

 

Edit: @r1dermon, the entire process of adding vaseline is to make sure the fuel keeps its form and stays solid and does not absorb water. Adding the thinner is to integrate the vaseline into the mix even-spread. After adding the thinner one must wait till the thinner is gone and the fuel is dry again to press.

Edit2: The vaseline addition also makes the composition safer to handle.

Edited September 15, 2011 by bonkers

[r1dermon]

the only reason i ask is because i was told by a well respected rocket maker after he launched 3 tremendous whistle rockets, that he uses nothing but dry oxidiser/fuel and presses them dry in the tube. no tricks. naturally, every whistle rocket making guide i've read has recommended mineral oil or vaseline...etc...so it came off a bit strange to me...but his rockets are definitely not slouches.

[dagabu]

the only reason i ask is because i was told by a well respected rocket maker after he launched 3 tremendous whistle rockets, that he uses nothing but dry oxidiser/fuel and presses them dry in the tube. no tricks. naturally, every whistle rocket making guide i've read has recommended mineral oil or vaseline...etc...so it came off a bit strange to me...but his rockets are definitely not slouches.

 

Hmmmm, nobody I know except a person that hates rockets who doesn't use a phlegmatizer. Is that someone here?

 

The powder with no phlegmatizer is really dusty and is a PITA to work with. I second the use of copper oxychloride, it works for thrust but the sound sucks

 

 

-dag

[bonkers]

Hmmmm, nobody I know except a person that hates rockets who doesn't use a phlegmatizer. Is that someone here?

 

The powder with no phlegmatizer is really dusty and is a PITA to work with. I second the use of copper oxychloride, it works for thrust but the sound sucks

 

 

-dag

 

Thats why I only use copper oxychloride for the core, the sound of the core isn't all that anyways. In that manner I have maximum thrust and afterwards a nice sound created by the iron oxide.

[dagabu]

Me too bonkers. Do you like sodium or potassium benzoate better for sound?

 

-dag

[drthrust]

has anyone pressed whistle fuel dry?

 

 

 

ive seen dry pressed rockets, from a uk member on this forum, pot benzoate and no catalyst and the fuel grain looked really pretty all in white and they where the best preforming of the evening . but the extra performance comes at a price.....

 

omitting the Vaseline, mineral oil,castor oil etc is ok if you've got balls of steel as it acts as a desensitizer, you can turn flash mixes into flare mixes with the for-mentioned, loose whistle is very powerful indeed why factor in extra risk?

[dagabu]

I do it solely for the lessened water absorbency, no other reason.

 

-dag

[allrocketspsl]

I would press dry 70/30 about two increment then the rest bp or bp then 34/ way up 70/30 dry,the first gave the rocket a kick no whistle sound the latter when the whistle kicked in a nice soft whistle would sound off,thats when I had a press,would press dry small inserts also with dry 70*30(potassium benzoate)

[bonkers]

I only used potassium benzoate so far but i'm sticking to salycilate because it is less expensive for me, and I like the sound of it.

Sodium benzoate has been found to have a better sound vs potassium benz. but I have only tested the potassium version.

 

What are your findings in this matter?

Edited September 15, 2011 by bonkers

[dagabu]

I only used potassium benzoate so far but i'm sticking to salycilate because it is less expensive for me, and I like the sound of it.

Sodium benzoate has been found to have a better sound vs potassium benz. but I have only tested the potassium version.

 

What are your findings in this matter?

 

Interesting:

 

Here, benzoate is by far cheaper, the sound is a pure tone with no warbling like the sali. Sali has a lot more thrust and most like that but i do like to play with it mixed with BP so the reduced thrust with nozzled motors is a good thing for me.

 

-dag

[bonkers]

I have a question about whistle and I'm wondering if anyone could help me:

Does anyone know how much gas output per gram of fuel whistle give?

And at what density is pressed whistle?

[Mumbles]

The gas output shouldn't be hard to calculate on your own. The standard whistle mixes are nearly stoichiometric. If you just calculate the stoichiometric one, the others should be relatively similar.

 

As far as density, I don't know anyone who actually does that as may be common with BP. Typically the rule of thumb I see for whistle rockets is around 8800psi, so whatever density that presses to is good enough.

[bonkers]

The density was not for knowing how far to press, more to know how many gas per volume the fuel gives.

Meanwhile I have prepared a couple of tests to determine the temperature, gas output, and pressed density of the fuel.

I will compare results with theoretical ones too, thanks for the tip.

 

Is it advisable to use a rocket sleeve in very thick steel or just use something that will fail when the fuel accidentally ignites?

I was thinking to use erthalon (company plastic name) for sleeve because of the hazards when using steel but if the steel sleeve is made to be capable of handling something like 3000 bar (~45000 psi), would it reduce the danger? I guess the only way for the gas to expand would be next to the rammer, thus not exploding a couple of feet from your face.

I see the tools from Wolter are thick aluminium, it seems to me if the rocket fails, the entire sleeve fails giving an enormous bang when shattering into pieces at high velocity.

This concerns me a lot, what if I use a plastic-that-doesn't-shatter-like-PVC and it blows up, even my 8 mm steel plate shield and -45 db ear protection would give me a serious blow when pressing 3lb's whistles that go wrong.

Edited September 20, 2011 by bonkers

[Mumbles]

I assume you're talking about the "clam shell" rocket sleeves that Rich Wolter makes? By far the weakest point on those things is the hinge. They've been tested to failure before. With smaller rockets they open up with some damage to the sleeve, but stay usually stay in one piece. On larger rockets I've been told that they simply split apart staying in two large pieces, plus probably a few small pieces from the hinge, nuts, etc. They do not shatter. If you keep the opening pointed toward you, the large heavy pieces will not be directed toward you. The splitting allegedly absorbs a lot of the energy. With a proper shield, you shouldn't have to worry.

[drthrust]

thats interesting, does anybody have a pic of a failed ( bang!) clamshell ?

[drthrust]

ahh found one, doesn't look to bad http://www.pyrobin.com/files/clamshell3.jpg Edited October 29, 2011 by drthrust

[Potassiumchlorate]

I haven't made any whistle rockets, since I lack a proper press for that, but you can use chlorates, yes. Of course it will be more sensitive, though. I'd prefer potassium perchlorate/potassium benzoate to start with. The most powerful you can make with "ordinary" pyro chemicals is probably potassium (per)chlorate/sodium salicylate/copper oxychloride.

[Col]

ahh found one, doesn't look to bad http://www.pyrobin.com/files/clamshell3.jpg

 

I wouldn`t want to be anywhere near it , blast screen or no, judging by the state of those locking bolts

[drthrust]

ive been pondering making a clamshell for a while and have thought about what would happen in a case like that, maybe you could machine a groove mid point into the the locking bolts to act as a weak spot to get a "cleanish" break

[dagabu]

ive been pondering making a clamshell for a while and have thought about what would happen in a case like that, maybe you could machine a groove mid point into the the locking bolts to act as a weak spot to get a "cleanish" break

 

Yes, that is what a sacrificial bolt is, a groove is milled down to a pre-determined breaking point so that a known release can be had. A very good example is the dog-bone that is used to break when the catapult on an Aircraft Carrier reaches the proper pressure and launches the shuttle.

 

-dag