how to store 'dip'

[kramer714]

I'm about to mix up some more pyrogen dip and started to think about the best way to keep it. I currently use a glass jar with a plastic top (from Magnelite kit). and was thinking a shaterproof plastic container may be a better choice.

Sounds dumb but any suggestions on a container for keeping dip?

[kandsrockets]

I like using amber colored glass jars with a chemical resistent lid. I tape my lid where the lid meets the jar with electrical tape to store it. I wrap bubble wrap around it for storage and keep in a ammo can. I have had some stored up to 8 months and was still good when I got it out to use.

[kramer714]

where do you get your jars?

[kandsrockets]

I found mine on Ebay. I do not think the color matters, it was what I found when I was looking for them.

[Handeman]

I bought a couple of small paint jars at Micheal's Crafts that are for storing air brush paints. I was having problems with the acetone evaporating from the NC lacquer. It's been 2 months so far and no evaporation yet.

[Kaycee]

I use a glass container with a plastic lid that's tightly sealed.


I store my mixture in the fridge.

[luke strawwalker]

I use a glass container with a plastic lid that's tightly sealed.


I store my mixture in the fridge.

Just don't put it on the burger buns!!! LOL:)

"Honey, I think these pickles have gone bad... " :y::bangpan:

:neener::D:dark: OL JR :)

[rocket999]

Just don't put it on the burger buns!!! LOL:)

"Honey, I think these pickles have gone bad... " :y::bangpan:

:neener::D:dark: OL JR :)

:roll::roll::roll::roll::roll:

That is what I thought when I read that...

Sam

Oh, and I store my pyrogen in film canisters, because they are free.:)

[bobkrech]

You are asking for serious trouble if you use glass jars (with or without threads) and/or metal tops to mix/store pyrogen "dip" concoctions. Once the solvent goes away (and it will go away in the thread lands first), you end up with the equivalent of flash composition that is very friction sensitive. ( If it reacts with a metal lid, it can even be more so.)

It's possible for the mix to go off when you are opening or closing the jar, and this can shatter the glass. As for the glass jar, glass doesn't show up in X-rays and requires exploratory surgery.


The bottom line is you should only make what you plan to use and don’t store the mix.


Bob

[Handeman]

You are asking for serious trouble if you use glass jars (with or without threads) and/or metal tops to mix/store pyrogen "dip" concoctions. Once the solvent goes away (and it will go away in the thread lands first), you end up with the equivalent of flash composition that is very friction sensitive. ( If it reacts with a metal lid, it can even be more so.)

It's possible for the mix to go off when you are opening or closing the jar, and this can shatter the glass. As for the glass jar, glass doesn't show up in X-rays and requires exploratory surgery.


The bottom line is you should only make what you plan to use and don’t store the mix.


Bob

Bob, Please don't take this the wrong way. I completely agree with your final conclusion,
only make what you plan to use and don’t store the mix.although for other reasons.

We should know the risks and you brought that forward, thank you.

I just disagree with your the implication you made with this post. You gave us the worst possible scenario and left us with the assumption that this is a relativity common occurrence. To me that is like telling us that the next time we drive our car, we are going to be killed by a drunk driver. That is a possibility, but the probability is really small and has to be taken into account. How many people have actually had a glass container explode because of reactions within the theads of the lid?

With all the things that can have a negative affect on my health, using a glass jar to store my "dip" is one of the last ones I'm going to worry about.

[bobkrech]

Handeman

As a professional physical chemist and safety expert who has worked with rocket propellants and explosives for 38 years, I respectfully disagree.

I don't want to preach, but accidents do happen, and people can get hurt. I've had my share of unintended explosions making unstable compounds at my day job, but we knew that the material would explode, and by planning for that eventuality and by having designed the system to protect me from blast and flying projectiles, have walked away shaken but unhurt, as injuries can be prevented with he proper use of PPE (proper personal protection equipment) and blast shields.

As a safety expert, I have been asked to investigate a number of unintended explosions, and without exception, they occurred because a mistake was made in the handling and/or processing of the explosive material. For example, a incident I investigated involved a common mistake of using metal spatula to scrap a new energetic material from laboratory glassware. Since many energetic materials (or unexpected reaction byproducts) are friction and/or pressure sensitive, they can detonate if treated in this manner. While the event would not have occurred if the individual had used a rubber spatula, he was not injured because he wore the proper PPE (safety glasses, face shield, lab coat, apron and gloves and our policy restricted the quantity of material he could use to a level that would not severely injure him if it did detonate.

I really believe that the instructions of the manufacturer of a product should be followed. I have attached the manufacturers directions for magna-lite igniters who ships their component in plastic bottles. The instructions clearly state "Dispose of any leftover or unwanted pyrogen in accordance with all applicable laws. We recommend that you burn it. Storage life of unused pyrogen has not been determined at this time." They also state "Never use a metal object to stir any of the bottles in your e-match dip kit." which I would extend to metal bottle caps.

If you really feel the need to store an unused dip mix (which I don't recommend), please use a polyethylene or polypropylene jar and cap such as the product found on the attached page from www.mcmaster.com (http://www.mcmaster.com) and leather gloves with safety glasses and a face shield.

Wide-Mouth Plastic Jars


(G) Heavy duty translucent polyethylene jars

have extra-thick walls, making them our most durable plastic jars. They are made of low-density polyethylene and FDA-compliant resins. Cap is translucent low-density polyethylene and has an inner leak-proof seal. Maximum temperature is 176° F.



Bob




PS. Kaycee - never store this in a home refrigerator. They're not explosion-proof and you don't want solvents in your food. It's possible, but not likely (but only due to quantity of solvent), that your refrigerator could explode if the solvent spilled. The ignition source can be any electrical items in the refrigerator (thermostat, fan motor, light bulb, etc.)

[WillMarchant]

It looks like Bob is referring to part number 4489T31 for the smaller size...


If you really feel the need to store an unused dip mix (which I don't recommend), please use a polyethylene or polypropylene jar and cap such as the product found on the attached page from www.mcmaster.com (http://www.mcmaster.com) and leather gloves with safety glasses and a face shield.
Wide-Mouth Plastic Jars

(G) Heavy duty translucent polyethylene jars have extra-thick walls, making them our most durable plastic jars. They are made of low-density polyethylene and FDA-compliant resins. Cap is translucent low-density polyethylene and has an inner leak-proof seal. Maximum temperature is 176° F.

[Adrian A]

I really believe that the instructions of the manufacturer of a product should be followed. I have attached the manufacturers directions for magna-lite igniters who ships their component in plastic bottles. The instructions clearly state "Dispose of any leftover or unwanted pyrogen in accordance with all applicable laws. We recommend that you burn it. Storage life of unused pyrogen has not been determined at this time." They also state "Never use a metal object to stir any of the bottles in your e-match dip kit." which I would extend to metal bottle caps.

Although they ship the components in plastic bottles, Magna-lite provides a threaded glass jar with a hard plastic cap for mixing and storing the dip. I have had problems with the pyrogen gluing the cap on when I failed to completely remove the excess dip from the edge of the bottle. I have some polyethylene covering the jar now, but I'm wondering how sensitive to friction is the magna-lite? I use a wooden stirrer to stir it up before use. Is there a controlled test I can do to ignite a sample by friction to get a better feel for the risk?

[bobkrech]

You might be able to do something like the official friction characterization test: the ABL friction test (UN Test 3(b) (iii)).

(1) Introduction. This test determines the sensitivity of substances to friction. The test substance is subjected to vertical compression force under a non-rotating wheel, while the substance is moved in a horizontal direction on a sliding anvil. It is intended for both liquid and solid substances.
(2) Apparatus and materials. Figure 5–12 illustrates the apparatus. The wheel and anvil are constructed of steel with a finish of 1.52 micron ( 60 micro-inches). Force is applied hydraulically through the non-rotating wheel to the sample which rests on the anvil. A pendulum impacting on the edge of the anvil propels the anvil at a known velocity, perpendicular to the compressive force that is applied to the sample. Normally, the anvil slides 2.54 cm (1.0in). The compressive force is measured by a gauge. The initial velocity is determined by calibration.
(3) Procedure. A sample of test substance at 25°C, and in a thin uniform layer (equivalent to one particle thickness for solids based on largest particle size in distribution) is placed on the anvil, under the wheel, 0.64 cm (0.25 in) wide, and extending 2.54 cm (1.0 in) along the sliding contact surface. The wheel is lowered onto the substance and force is applied to the wheel. An initial force of 4450 N (1,000 lb) is typical. In practice the force is changed in increments where the lower value is 75% of the higher value. Maximum values of 8000 N (1,800 lb) and minimum of 44 N (10 lb) are used. A velocity of 0.9 m/sec (3 ft/sec) is a typical choice, although increasing or decreasing velocity in increments of 0.3 m/sec (1 ft/sec) or more may be found useful in additional comparisons. The velocity is changed simply by altering the pendulum angle from vertical from which the pendulum is released. (Thirty degree approximates to 0.9 m/sec (3 ft/sec) slide velocity.)) A new sample is used on each trial, with cleaning of the anvil done between trials. An iterative procedure is used to determine the highest compressive force at which no positive (+) results are obtained in 20 trials. This value is considered the Threshold of Initiation (TIL). Dry pentacrythrite lentranitrate (PETN) is used as a reference explosive for evaluating the test results. Report the PETN results along with the sample results.
(4) Criteria and method of assessing results.
(a) A trial is considered positive (+) if any one of the following results is obtained:
1. Visible sparks.
2. Visible flame.
3. Audible explosion.
4. Loud crackling noise.
5. Detection of reaction products by a gas analyzer.
(b) Discoloration of the sample holder, crepitation (i.e., subdued cracking due to crumbling of the sample), or slight odor in the absence of indicators given by paragraph 5–4b(4) (a) above, are not considered positive (+) results.
(c) A substance with friction sensitivity equal to or greater than dry PETN, i.e., lower compressive force, is considered a positive (+) result and is too sensitive for transport. PETN has a TIL of 184 N (41.4 lb) at 0.9 m/sec (3 ft/sec).

[Uncrichie]

I completely agree with what BobK has presented. You can never be too safe. Any leftovers should be properly disposed of and heres another reason why. Most if not all of these recipes are of a flash composition. Once they dry in the container you are now the proud owner of a High Explosive. Unless you have the proper storage and licensing I would not keep leftovers. Uncrichie.

[ben_ullman]

I completely agree with what BobK has presented. You can never be too safe. Any leftovers should be properly disposed of and heres another reason why. Most if not all of these recipes are of a flash composition. Once they dry in the container you are now the proud owner of a High Explosive. Unless you have the proper storage and licensing I would not keep leftovers. Uncrichie.

I disagree they are flash components. I have seen flash and hit flash with a 10lb sledge. Very dangerous but interesting animal. I would be more than comfortable smashing some dip with a sledge hammer. There may be some variant of flash involved but once diluted by the solvents I would think the effect of pure flash is almost gone.

Just my :2: and observations.

Ben

[bobkrech]

College Chem 101 - Any finely divided metal powder and any finely divided oxidizer when mixed together is a flash powder. When ignited they give off a short intense burst of light and heat.

So does an igniter...

[kandsrockets]

Well here is the real question. How many cases has there been where a bottle of pyrogen blew up while opening?

[shreadvector]

Well here is the real question. How many cases has there been where a bottle of pyrogen blew up while opening?


Just one quick Googling. Other search variations will yeild additional references.

http://www.google.com/search?hl=en&q=chemical+explosion+cap+threads+glass+bottle&aq=f&oq=&aqi=

[kandsrockets]

Just one quick Googling. Other search variations will yeild additional references.

http://www.google.com/search?hl=en&q=chemical+explosion+cap+threads+glass+bottle&aq=f&oq=&aqi=

Well that would be okay if it was based on our pyrogen formulas

[shreadvector]

Well that would be okay if it was based on our pyrogen formulas


"Other search variations will yeild additional references."

[MaxQ]

I disagree they are flash components. I have seen flash and hit flash with a 10lb sledge. Very dangerous but interesting animal. I would be more than comfortable smashing some dip with a sledge hammer. There may be some variant of flash involved but once diluted by the solvents I would think the effect of pure flash is almost gone.

Just my :2: and observations.

Ben

<I have seen flash and hit flash with a 10lb sledge. Very dangerous but interesting animal.>

So.....THAT's what you used in that N motor in black five......

[ben_ullman]

<I have seen flash and hit flash with a 10lb sledge. Very dangerous but interesting animal.>

So.....THAT's what you used in that N motor in black five......

haha no!! :gavel: Ive used flash to make salutes for some pyrotechnic shows. And the class we took he had us hit a small bit with a sledge hammer. It was insane

Ben

[MaxQ]

haha no!! :gavel: Ive used flash to make salutes for some pyrotechnic shows. And the class we took he had us hit a small bit with a sledge hammer. It was insane

Ben

Done a little reading here and there on the subject myself..and it is that.

[r1dermon]

haha no!! :gavel: Ive used flash to make salutes for some pyrotechnic shows. And the class we took he had us hit a small bit with a sledge hammer. It was insane

Ben

hope you've got a type 20...mr ben.

to interject here, i wouldn't classify dried pyrogen the same as "traditional" flash powder...that is to say, aluminum flash which decomp's at a supersonic rate. rather, the flash that's produced in a pyrogen slurry, i would categorize somewhere between traditional flash, and some type of exotic thermite. typically, pyrogen isn't specifically designed to explode, rather, it's designed to transfer heat energy efficiently by utilizing a high proportion of fuel:oxidiser, making for more molten metals being projected upon initiation.

regardless, in my limited experience, i would heed the advice of bob on this one. the risk is far to great to disregard when a poly container could be used. if a glass container is going to be used, i would highly suggest wiping the threads with an acetone soaked rag before capping it, and maybe storing it with a little "extra" solvent. that's all i've got on the subject.

and BTW...flash powder is not a high explosive. only in large quantities as described by the govt. but outside of that realm, it behaves a lot differently than a true high explosive. TNT or PETN, traditional high explosives, propogate via a shock wave, which the rest of the material is initiated from...thousands of meters per second are regularly attained. low explosives propogate via a flame front, 1 grain of composition sets off the next, which sets off the next...etc...a lot slower, as fast as it is.

some low explosives, can propogate at near, or higher than the sound barrier, but are usually highly friction sensitive and unstable. (ie armstrongs mixture). most of the mixtures like that are classified as primary explosives, making them appear to be high explosive compounds...however, "Technically", they dont behave the same, i think it's an important distinction to be made scientifically.

also, to my knowledge, no flash composition has ever displayed the munroe effect. correct me if im wrong?

[BsSmith]

I stored my magnalite in the included jar.

It dried out completely in a year, and the cap was tight. It needs a much more airproof bottle.

[Adrian A]

I did some informal sensitivity tests on some magnelite that was dried onto a stir stick for months. It had been pretty well coated. I tried striking it like a match on the side of a concrete step. Nothing. Tried doing it harder, faster, still no reaction. I got out a hammer and pounded the stir stick flat against a concrete patio. The wood was totally mushed, and there was no reaction. Hmm. Maybe the wood cushioned the blows. So then I saw that there was a little bit that had flaked off of the stick. If you took a 1mm thick slice of a pea, that's the size of this part. I hit it with the hammer against the concrete and CRACK! it exploded. Not fizzled, not whooshed. It was a sharp bang that left my ears ringing (shoulda worn ear protection). I was surprised that the impact made it behave completely differently than it does when it is simply ignited. I'm not too worried about friction on the threads now for myself (of course I'm not telling anyone else not to worry about it), but I have new respect for avoiding high-pressure impacts.

[cobalt]

There really is no "correct" way to store a composition that should not be stored in the first place, IMHO. Just lesser evils.

[r1dermon]

I did some informal sensitivity tests on some magnelite that was dried onto a stir stick for months. It had been pretty well coated. I tried striking it like a match on the side of a concrete step. Nothing. Tried doing it harder, faster, still no reaction. I got out a hammer and pounded the stir stick flat against a concrete patio. The wood was totally mushed, and there was no reaction. Hmm. Maybe the wood cushioned the blows. So then I saw that there was a little bit that had flaked off of the stick. If you took a 1mm thick slice of a pea, that's the size of this part. I hit it with the hammer against the concrete and CRACK! it exploded. Not fizzled, not whooshed. It was a sharp bang that left my ears ringing (shoulda worn ear protection). I was surprised that the impact made it behave completely differently than it does when it is simply ignited. I'm not too worried about friction on the threads now for myself (of course I'm not telling anyone else not to worry about it), but I have new respect for avoiding high-pressure impacts.

commercial igniters from china, 1.3g ones used for fireworks, (but can be used for rocketry) have been blamed for a number of fatal accidents in the industry based on it's friction sensitivity. in-fact, some accidents occured when inserting the Ematch into the QM, and the friction of that caused the chain reaction of events, starting with the ematched shell exploding. not sure about the sensitivity of "magnelite", but different comps will produce different results.

[kramer714]

wow, and I figured someone would just say baby food jars...

Ok, since I started this mess.... sounds like a couple of different problems, asking the chemist out there (you know who you are).

1) I am assuming that nitrocellulose (ping pong balls / acetone) lacquer is safe to store using good 'flammable' housekeeping

2) For nitrocellulose, any good sealing container should keep it liquid.

3) If you use a commercial dip, it would be a good idea to wipe the threads off on the jar before closing it.

4) Plastic jar better than glass - no metal .

5) gloves and safety goggles a must (duh, but haven't we all done it 'just this time')

6) Mix up as little as you can at a time, none in storage may be best.

7) Could one of the dip vendors address sensitivity.

8) dipping in nitrocellulose, dusting with dry BP and then re-dipping in nitrocellulose may be (albeit lower performance) way of making igniters without having 'dip'

9) Has anyone tried to determine the sensitivity of commercial igniters? Whack a first fire? Beat a copperhead? to see if they are any worse than the commercial dip?

10) has there ever been a case where an igniter went off while being installed in an AP motor? Home made or commercial igniter?

[shreadvector]

You forgot to start that last post with "Dear Rosanne Rosannadanna, ..."


And I think you are writing from Ft. Lee, New Jersey.

:D;)

[Reed Goodwin]

I just store my Quickdip in the plastic jar it came in.
Reed

[Mike Di Venti]

I store my magnelite in the provided bottle.
I've been using that stuff for 6 yrs w/ no safety issues.
It does tend to dry out some but I just add some more acetone to it.

It used to come in HDPE plastic bottles but they stopped using those because the acetone was bleeding through the plastic bottle.

These pyro-dips cannot be be in small quantities as per manuf. instructions on how to make it.
(Well, I shouldn't say you can't, but the manuf. doesn't give directs on how to only make 2/3 the supplied amount or enough to make 10 ignitors)

The supplied chem. are already premeasured to make a given amount.

As for storing it your fridge....I wouldn't do that.

I keep mine in a plastic box in my field box with some "dog barf" wadding around it.