Failing with potassium perchlorate as rocket propellant.

[NightmareNeighbour]

Hi.

 

Recently i got my hands on some potassium perchlorate and somhow happened that it is the only oxidizer i have at the moment. All experiments with it as a propellant component failed. Particular problem i want to address is pulsation that occurs in the rocket, it extinguishes the combustion and sometimes lead to explosion.

[Mumbles]

You'll need to give more details, like what kind of fuel, how you're making the rockets, etc

[dagabu]

Hi.

 

Recently i got my hands on some potassium perchlorate and somhow happened that it is the only oxidizer i have at the moment. All experiments with it as a propellant component failed. Particular problem i want to address is pulsation that occurs in the rocket, it extinguishes the combustion and sometimes lead to explosion.

 

Sounds like you are subbing 1:1 KNO3 for Perc. Is that correct?

[NightmareNeighbour]

Rocket type:

 

Simple, tube with clay nozzle.

 

Materials used:

 

Cardboard tube/poliethelene tube/PVC tube, clay/kitty litter.

 

Rocket dimensions:

 

Tube inner diameter aprox. 16 mm

Fuel chamber lenght 20/30/40 mm

Nozzle 3/3.5/4/4.5/5 mm

 

Fuel:

 

KCLO4+Sucrose aprox 75%/25% (best candidate)

KCLO4+Charcoal+sulphur aprox 75%/15%/10% (exploded)after added parafin wax 5% for binder it started jerking like the asphalt compositions

KCLO4+Asphalt 76%/24% (Pulsating)

(KCLO4+Asphalt 76%/24%)+(KCLO4+AL 2:1) 70%/30% (Pulsating hard if fulechamber 40mm can explode)

KCLO4+Epoxy 75%/25% (uneven burn due to separation while hardening(didn't test in a rocket thou))

Edited December 29, 2010 by NightmareNeighbour

[NightmareNeighbour]

Sounds like you are subbing 1:1 KNO3 for Perc. Is that correct?

 

Well,not quite. I try to use some formulas i found on the net but the idea of BP substitute remains.

Anyway the idea is to do deliver safely some payload(Flash) at zero hour January 1st.

As soon as my testsite(xD) will cool I'l try to upload some vid's

Edited December 29, 2010 by NightmareNeighbour

[dagabu]

Sorry, you lost me at PVC and flash. I consider that a pipe bomb.

[NightmareNeighbour]

Got some result's on vid's, as for PVC and polyethelene i use for testing ONLY, well at least PVC. It's very frustrating to wrap up cardboard with glue and dry it, and then do it again and again just to destroy it without results.

PVC can be reused if it didn't shatter or crack.

 

In the vid's rocket is loaded with the 4th composition 30mm fuel lenght 3.5mm clay nozzle (for ignition just a pinch of 2nd comp. put directly on the engine)

[davis050594]

so what you are saying is you would rather have a test rocket cato and send dangerous, possibly deadly, shrapnel flying towards you, rather than rolling a tube? I made one batch and in 30 minutes had 4 solid tubes. Could've easily made more in that period of time but I didn't have enough glue.

If you can't afford to do the hobby safely, don't do it at all. Pvc is not safe. Cardboard is. There are risks in everything, there is no reason to add a risk to something.

 

 

[NightmareNeighbour]

so what you are saying is you would rather have a test rocket cato and send dangerous, possibly deadly, shrapnel flying towards you, rather than rolling a tube? I made one batch and in 30 minutes had 4 solid tubes. Could've easily made more in that period of time but I didn't have enough glue.

If you can't afford to do the hobby safely, don't do it at all. Pvc is not safe. Cardboard is. There are risks in everything, there is no reason to add a risk to something.

 

 

 

 

Guys, i don't know what's wrong with the forums nowdays but somehow every time I post something almost anywhere on any subject(dangerous or not), someone shows up and turns the topic to the soap opera O_o

 

Is it the new guy thing ?

Is it iwanasoundimportant thing ?

Is it some kind of bonus for posting ?

 

Where did you see me writing about "to" in your cato ? The PVC engine testing is performed upside down in the chamber lined with bricks behind the steel door.

And what the hell happened with "stick to the topic" rule? It's simple, you post your comment acording to the subject and if you see danger you just say something like this "Hey man, that looks DANGEROUS, you should not do that" Seee, simple.

 

Now, if there is no one who can enlighten me with explanation of what is happening with my engine or REASONABLY introduce me to the dangers associated to my actions please! just walk by and don't disturb, thank you.

 

 

 

 

 

[dagabu]

My apologies:

 

"Hey man, that looks DANGEROUS, you should not do that"

 

It comes down to this, you are not using "normal" chemicals (together), tubes, methods to make rockets. Being a pyrotechnical forum, and having witnessed several accidents happen within our ranks, we are a little touchy about people showing up with the very first post involving the use of pot-perc and finely divided aluminum.

 

Here is the rundown:

Potassium Perchlorate normally is used with Potassium Benzoate, Sodium Benzoate or Salicylate to create whistle fuel along with a phlegmatizer and liquid (white gas or the like) to dissolve it in. The pot-perc used with any of your listed fuels isn't something I have seen here and a quick Google doesn't come up with much either.

 

So if you come here to ask a question in which your desire is to get buy-in on a non-accepted method, you use materials to improvise your desired rockets that have inherent risks that we really dont want the younger and less experienced members to be associated with, then...

 

...you gets what you gets.

"Guys, i don't know what's wrong with the forums nowdays but somehow every time I post something almost anywhere on any subject(dangerous or not), someone shows up and turns the topic to the soap opera O_o'''

 

That right there is pretty telling, read a little, get used to the cadence, read the safety rules, say hello and relax. If ALL the forums feel like a soap opera then perhaps it is your involvement that is making it feel so.

 

Welcome to APC, lets figure something out for you.

[davis050594]

Guys, i don't know what's wrong with the forums nowdays but somehow every time I post something almost anywhere on any subject(dangerous or not), someone shows up and turns the topic to the soap opera O_o

 

Is it the new guy thing ?

Is it iwanasoundimportant thing ?

Is it some kind of bonus for posting ?

 

Where did you see me writing about "to" in your cato ? The PVC engine testing is performed upside down in the chamber lined with bricks behind the steel door.

And what the hell happened with "stick to the topic" rule? It's simple, you post your comment acording to the subject and if you see danger you just say something like this "Hey man, that looks DANGEROUS, you should not do that" Seee, simple.

 

Now, if there is no one who can enlighten me with explanation of what is happening with my engine or REASONABLY introduce me to the dangers associated to my actions please! just walk by and don't disturb, thank you.

 

 

 

 

 

 

*this was written before dag's showed up, but he must've clicked post before me. I think is still worth keeping up,

 

I am a newbie as well. We have to watch out for eachother in this hobby. When someone comes on here saying that they are new, testing different oxidisers in rockets that it is fair to assume are rammed, using pvc tubes, and looking to carry a flash header, it raises some alarms. This is a public forum. Heck, for what the government is concerned you are just making pipe bombs. That does not help us. Even if what you are doing is safe under the right circumstances, the government does see that. All they know is that what you could be doing could have a slight possibility of hurting someone. Remember, it is the governments job to protect us from ourselves because we cant. http://www.thebeerbarrel.net/images/smilies/facepalm.gif

Edited December 29, 2010 by davis050594

[dagabu]

Sweet head-slap Davis!

[NightmareNeighbour]

Thank you, I appreciate what you guys said!

 

And I am ready for suggestions, all i want now is to get some stable engine working so i can get some lift off.

 

 

[dagabu]

Thank you, I appreciate what you guys said!

 

And I am ready for suggestions, all i want now is to get some stable engine working so i can get some lift off.

 

 

 

In that, I dont think I can help. I am pretty much a black powder and whistle guy Hybrids too. I will be experimenting with asphaltum in place of charcoal this spring in hopes that I will find a good black smoke day time rocket motor but even my sugar rockets use KNO3, not pot-perc.

 

Go grab some stump killer, I can make some recommendations for rockets at that point.

[asilentbob]

How are you mixing and pressing the propellant?

 

If the grain is not dense you will have problems. Please don't tell me you are ramming this stuff with a hammer.

[NightmareNeighbour]

As funny as it sounds I can't find any of the KNO3 in the stores and I never saw it as a "stump killer"

 

Also i got this plan B in case I fail, it consists of transforming ammonium nitrate/calcium nitrate that I got, to sodium nitrate using sodium bicarb and then going the rocket candy way cause I broke my charcoal mill last time I used it.

 

And regarding the mixing, pressing techniques. First two comps, simply shaked and hammered in, other stuff except epoxy (asphalt is heated and the powder component(premixed) stired in) is very malleable and can be easily put in place using moderate hand pressure.

The number 2 comp. (KCLO4+Charcoal+sulphur aprox 75%/15%/10%) originaly(without the binder) does not compress under the hammer as you can simply tap the rocket and it just falls out of it (I think this was the purpose why it resulted in explosion that only time I used it)

Edited December 29, 2010 by NightmareNeighbour

[dagabu]

Hi-Yield Stump Remover is almost 100% Potassium Nitrate. The issue with Sodium Nitrate sugar rockets is that you will have an almost impossible time keeping it dry. I could never get it to light, they sputter and go out.

[Mumbles]

First things first, I would stop ramming any of those. Sulfur and sugar are known sensitizers to impact of chlorates and perchlorates. It also sounds as if you're drilling into the comp. I can't say I recommend it, but at the very least take the added safety step of hand powering the drill.

 

I think you're cutting it a little close to be trying to make stable experimental rockets in time for new years.

[psyco_1322]

Agreed with Mumbles, those aren't the best to be ramming. If you had some kind of press, you would be better off.

 

I take it that the videos are of the Sugar based propellant. Whats wrong with those motors? If that was the whole motor being burnt up, I bet they would fly. The little sputtering is not really that big of an issue, its likely coming from stuff crusting up around the nozzle. You could try to add around 5% Al to the sugar fuel and get a smoother burn possibly. You want your rocket fuel to burn as clean as possible. The fuels you are using, I've seen some of them before, they are more for High Powered Rocketry. Those motors are made a tad different than pyro rockets and are under way more chamber pressure too.

 

Again, ramming isn't a good idea with Perchlorate based anything, but if you are going to do it, use some protective gear just in case. Id suggest at least a pair of leather gloves and face protection.

[NightmareNeighbour]

Yes I use a drill press for core/nozzle forming, the drill is set for lowest rpm and I do the core in many passes.

 

Engine you see in the video is loaded with modified GALCIT 61-C http://www.astronaut...es/comlants.htm ((KCLO4+Asphalt 76%/24%)+(KCLO4+AL 2:1) 70%/30% well atleast very similar) there is 10% Aluminium by weight.

No, the motor is not burnt up and I'd say it's hardly used 20% of it's propellant. In the next video i use the same engine, no refuling, just a pinch of other powdered fuel for ignition so it can continue burning it's main propellant and it starts off more vigorously due to increased surface area, then just dies with a spank.

I have no idea what's wrong with it, somhow i hoped it was a newbie mishap and the solution will pop right up.

It seems like some barier that the propellant can't pass and the only thing in common is Potassium Perchlorate.

 

Oh and i do where some safety gear, most of the time, impact goggle and when hammering, leather welding gloves.

Edited December 30, 2010 by NightmareNeighbour

[psyco_1322]

Good to hear you are wearing some gear.

 

Where are you getting the Asphault? I would think that by its self would be hard to get to burn. I'm curious on why you didnt just add the Al straight instead of with a oxidizer. The fuel value of oil is probably more than Al Id imagine. That might be your problem, the fuel may be to rich in oxidizer.

 

When KClO4 is mixed with odd things and is burned, it tends to flash off for a bit then sort of smolder and flash off again. So your issue kinda fits its characteristics.

 

Id say go back to the KCLO4+Charcoal+sulphur formula, use a 60:30:10 ratio and back off the wax to only 2-3%. Try that and see if you are getting closer to a more stable motor.

[WSM]

The one time I tried a GALCIT type propellant using KClO₄ and asphaltum, it failed miserably... until I added a little (read 2-5%, maximum) potassium benzoate to the mix. Then it came to life!

 

Do use safe practices; a press with a solidly mounted safety shield is a minimum. Lacking these would suggest holding off till they or something similar can be obtained. We would like to see you survive to become a contributing member to the community rather than a sad statistic. Please take our concerns in the light they're intended, we care about your safety and that of the community you work in.

 

Sincerely,

 

WSM

[TYRONEEZEKIEL]

Your pulsation of the thrust is called chuffing. That has to do with your nozzle geometry related to your propellant. try opening the nozzle a bit, you should see better performance. And certainly follow the steps these guys give. Very well experienced guys here

[NightmareNeighbour]

I get asphalt(I assume it's asphalt) from some leftover tar substance that was used to seal the shed roof.

In the Al addition I leaned to stoichiometric amounts fuel/oxidizer and actually got a little stiff for making modification to the base propellants. Got the 60:30:10 mixed up and loaded as 30mm chamber length 3.5mm nozzle/core, after ignition chuffed 2 times on 3rd blew the clay out.

 

The thing with getting the K/Na-benzoate, the only way I see it, is to actually synthesize it chemically from available toluene(solvent), regarding it's use as a stabilizer the process just got a considerable priority.

A press is not an option at the moment. A change to full face shield and less hazardous tooling/materials, I see as an acceptable compromise.

 

At first the experiments was all about nozzle diameter, it showed that chuffing barrier starts where the thrust is insufficient for lift off and inadequate to propellant potential.

 

Anyway, went with plan B at the last moment and ended up with drinking champagne while drying NaNO3 from water/ammonia mix. Despite the direct ventilation and considerable air exchange the place was reeking with ammonia. The product was 800g of NaNO3, heat gun proved to be an ultimate tool for last stage drying, just don't dry comps or easily ignited materials with it cause it occasionally sparks out a burning dust particles. First test 30/3.5mm 65NaNO3/25Charcoal/10Sulphur was an instant success. Moved to 40mm, run two tests then stick it up and WOOSH!(a little late but still sweet and uplifting) Needs some fine tuning thou.

 

Got two more vids just 4fun.

[Jonathan]

My two cents. I suggest anyone looking to use KClO4 in a propellant mix explore dextrin or red gum as fuel. Both oxidize energetically with K-perch and produce lots of gaseous products.