A Lesson In Safety! Could have been worse.

[RUUUUUN]

Me personally; I don't think you could generate enough pressure, quickly enough, with a hammer, to light BP. I am thinking either spark (doubtful with Al) or friction.... Has anyone else gotten BP to go off with a hammer strictly from impact or even heard of it occuring? I have never tried but I would assume that the drop rig for testing BP would have to be pretty stinking tall and have a pretty large mass(a tube going down the side of the sears tower with a nice large 5 or 6 kilo, bullet-shaped, piece of what ever nonsparking material you choose. Ojive down, naturally).

[new2pyro]

it kinda of snapped when I hit the last blow and then I saw a spark pop out the top of the tube.

[Mumbles]

Yes, BP can be set off with something like this, especially if the force is concentrated to such a small area. Another time it can be set off is if you seize the rammer and the spindle together. Twisting can also set any comp inside off. The best way in this case is to soak the whole thing in water, peal the tube off, and remove it then. I hear a penetrating oil really loosens the rammer and spindle up.

[new2pyro]

I always make sure to check the nopass line. I just went to the flat ram too soon. I haven't had the tooling but a week and a half and I guess I learned a lesson thankfully without injury.

[dagabu]

Me personally; I don't think you could generate enough pressure, quickly enough, with a hammer, to light BP. I am thinking either spark (doubtful with Al) or friction.... Has anyone else gotten BP to go off with a hammer strictly from impact or even heard of it occuring? I have never tried but I would assume that the drop rig for testing BP would have to be pretty stinking tall and have a pretty large mass(a tube going down the side of the sears tower with a nice large 5 or 6 kilo, bullet-shaped, piece of what ever nonsparking material you choose. Ojive down, naturally).

I will take a look back in my text books but I believe that a free drop of 50' is enough to reach Terminal velocity of 163 MPH.

 

When Developing lead hardening text in my cowboy shooting days (I didn't actually shoot cowboys) I mad a rig to test brinell scale hardness in lead (aprox) using a pneumatic cyninder and a release pin. There is documentation outlaying the specifics of the ball and such used so reaching the proper striking diameter of the indent was pretty easy. Using that known air pressure on the cylinder made for easily repeated strikes.

 

Using the same machine on pyrotechnic comps of 50mg, black powder would detonate at 73 PSI. I have no way of knowing how many pounds per square inch of force it created but it was pretty telling since it took 39 PSI to cook off sodium benzoate whistle and 12 PSI to cook off 70/30 flash.

 

What this all means is that, yes, striking pressure can indeed ignite BP.

 

D

[RUUUUUN]

Really? That is very interesting... So realistically you could make a blasting cap with a 2 gram booster of PETN or ETN and as long as the BP was pressed into a tube it will actually detonate? I was under the impression that KNO3 mixes (even KNO3/NM, to a certain point) were extremely hard to detonate and that they required massive boosters. IIRC Had to do with KNO3 being very endothermic and having a very high heat of explosion or somesuch nonsense like that... wow, I haven't thought about making KNO3 based HE for a long time, As soon as I began production of more complex explosives(ETN, TNP, NC), and found a source for AN, I simply dismissed it as a total waste of time because they required way to much booster to be economical.

[Mumbles]

I don't know if I'd say BP can detonate. There is a difference between impact ignition, self confinement, and detonation. I honestly don't even know about the KNO3 explosives. Most of what I heard is that it is simply there to correct oxygen balance and sensitize the other component(s) which is what actually go off. I wont go into too much detail as this isn't the place.

[FrankRizzo]

I agree, new2pyro. This same accident or varients whereby the hollow rammer has not been cleaned of powder build-up has happened to many people. Adding metals (which I know you didn't) definitely increases this risk. You should always use the hollow rammer until you are at least half a tube diameter (ID) above the spindle.

 

A real simple way of preventing that from ever happening again: Your local hardware store should have 3/4" shaft collars for ~$1. Pin the shaft collar to your flat rammer in a position such that the collar will hit the top of the tube before it's able to contact the spindle tip. A thin ring of split PVC pipe with a hose clamp around it to keep it clamped to the rammer would serve the same purpose and be even less expensive.

 

 

Ruun:

 

If the tube was sufficiently sealed, there could have been enough heat generated by the compression of the air alone. I doubt this is what happened however as the previous explaination is more plausible. Search "Fire Piston" on Google to learn about a neat little device used many years ago to start fire.

 

Or, Read this page:

http://www.onagocag.com/piston.html

[RUUUUUN]

Yeah, yeah, diesel effect, Boyle's law yadda yadda... I am gettin' ya now; When he said impact I automatically assumed that it would actually be detonation not deflagration. I was just getting hung up on the impact assertion.

 

Oh, and the "fire piston" is still used today, it is a survival tool that hikers can buy and it works much better than the ol' stick N' bow method (from MY experience, I think anyone who has actually tried rubbing to sticks together or making a nifty little bow and attempting to start a fire that way(VERY VERY DIFFICULT AND TIME CONSUMING!!!!) will agree that having a nifty little shaft that you can drop some dry moss down, insert a piston, and then smack the crap out of the top of the piston, to start a nice little ember, is very, very, handy.)

 

*EDIT* it double posted on me!!

Edited October 19, 2009 by RUUUUUN

[FrankRizzo]

Yeah, yeah, diesel effect, Boyle's law yadda yadda... I am gettin' ya now; When he said impact I automatically assumed that it would actually be detonation not deflagration. I was just getting hung up on the impact assertion.

 

Oh, and the "fire piston" is still used today, it is a survival tool that hikers can buy and it works much better than the ol' stick N' bow method (from MY experience, I think anyone who has actually tried rubbing to sticks together or making a nifty little bow and attempting to start a fire that way(VERY VERY DIFFICULT AND TIME CONSUMING!!!!) will agree that having a nifty little shaft that you can drop some dry moss down, insert a piston, and then smack the crap out of the top of the piston, to start a nice little ember, is very, very, handy.)

 

*EDIT* it double posted on me!!

 

I prefer a Bic or a misch metal striker for survival use, but yes, fire pistons are still carried by some "survival enthusiasts".

[gordohigh]

The thing about accidently using your hybrid tooling with your BP projects is whats bothering me (or any tooling). No matter how hard you try, accidental mixups still do happen. If we could implement a color coding system for tooling I think it would help tremendously. For instance, with most rockket tooling being made of aluminum, why not anodize hybrid one color, like red, and anodize bp tooling black, or any color but color code for easy identification. Anodizing is quite easy to do and even a home anodized tool would be a good quality. I have anodized several of my radio controlled helicopter parts using only rit dye and a sulphuric acid solution and a battery charger. It's been a few years so I don't remember the exact process but it was fairly easy. Even wood tooling could be color coded by using tape on a part of it that isn't used for anything but a handle or even dying the wood.

 

Anyway, I think color coding would make a significant improvement over no color coding, and could become the standards of the industry for those making it and selling it. As far as a collar installed, or made during the making of the tool seems like a great idea too as mentioned above by FrankRizzo.

[TheSidewinder]

Color coding is a very good idea.

 

Simple solution is to borrow some of the wife's/girlfriend's nail polish, and paint a stripe just below the top of all the rammers (where the hammer or press contacts it) for one set.

 

Repeat for all sets you have, with colors which contrast enough to be instantly noticeable.

[dagabu]

Visco cannon fuse is a fine product. Also an expensive one. Being water-proof;

a good hot fuse well suited to bad kids lighting M-80's and flushing them down a toilet.

Cannon visco costs around $36.00 per 100 ft. It has a burn rate of only 2.5 seconds per inch.

Which means you run like h-ll after lighting or, you use more fuse..$.

 

1000' at PGI last year for $20.00, green, 2mm, consistent and clean. They still had a case left when the lights went out.

 

More importantly:

 

What in the blue blazes does this have to do with the topic!?!

Edited July 28, 2010 by dagabu

[Mumbles]

Dude, you sound like a women, you talk without saying anything.

 

She is female.

 

I've paid around $70/1000ft a few years ago for some decent quality chinese. That is more fuse that I'll probably ever use. If I use more than 10 feet in a year, I'd be surprised. I have been trying to find a good source for good "american" visco though.

[dagabu]

Bring some powder and Dan will make some for you on his machine. He will be in the racket tent.

[TheSidewinder]

Sorry, deleted several completely irrelevant posts out of the topic, and threw the topic "flow" off a bit.

 

Carry on.

[dagabu]

Ahhhhhh, that feels much better. Thanks guys!

[Almamater]

thx for the tips

[deer]

Reminder that even hundred grams of rcandy in wide, open ended cardboard tube must be taken seriously.

 

Long story short, I was being an idiot and having no gloves and no fuse, directly ignited fuel by corner, with my inner palm facing tube end.

The moist fuel seemingly barely burned until it spontaneously blasted a 30cm jet right into my palm. Even while I jerked my hand out of the way as fast as I could, 700C needs no time to leave a smoking black tube imprint on your skin, make you visit hospital, have most of palms inner skin removed and leave me typing this with just one hand for quite some time I guess.

 

Plus, I don't even want to think about the curing process, explanations I'll have to do, works I'll miss or delay and the nice warm summer days I won't enjoy.

 

If you can go trough the hassle of setting up an experiment, bringing your tools and samples out, summer is no excuse not to drop a pair of gloves in your bag. Probably would've went away with small blister and slightly sore hand then.

 

P.S. Have Panthenol spray around. I Applied immediately and even the first doctor I saw said its good that I did so and it's all what they would've done before sending me to burns centre.

 

Edited June 12, 2015 by deer

[mikeee]

Things like that are suppose to happen on Mondays.

You most likely won't try that one again.

You learned a Pyro lesson today........ hopefully someone will learn from your mistake.

 

Ouchhhhhh!

[mabuse00]

Sorry dude.

 

Seems like little permant damage but a lot of pain for sure.

 

I guess it's only human to suffer from little mental blackouts from time to time... Sometimes one pays for them.

 

You're not the only one.

[rogeryermaw]

sorry for the pain you're in for. hand wounds are tough as there are so many nerves clustered there. all the best for recovery!!

 

thank you for sharing your experience. maybe the pain you have felt will teach the next guy not to go this route.

[deer]

A quick follow-up. It's been a month and only now it's healed enough to be almost fully usable. Wasn't as bad (deep) as it seemed initially, just large area and unpleasant location, so hopefully no permanent damage.

The skin is still too thin to do any rougher work barehanded, but it's well enough to not worry about tearing and infecting it when using gloves, as well as doesn’t hurt when put under pressure. Worst part still has some stiffness, but by the feel of it I expect it to go away as the skin regains thickness.

 

So the lesson learned - no amount or type of material is safe, the way you handle it determines what can go wrong. And even minor burns to critical body parts can put you out of business for a long time. Had it been any straight run of skin, it would just take a bigger "band-aid" and go unnoticed - protect your hands, eyes, and other important bits.

 

P.S. I'm not sure if this isn't against the rules (a little graphic), but if MODs say it's OK and it's useful, I can include pictures of wound 6 days after accident and how it's healed now.

P.P.S. Maybe MODs can move everything from #44 to separate thread (e.g. Rcandy sample test gone wrong), to keep this thread clean and rise awareness for people working with this composition.

Edited July 17, 2015 by deer

[stix]

Shit deer!!, I'm glad to hear that it wasn't as bad as it could have been.

 

In my earlier days I did some very unsafe things. When I look back, it was mainly luck that something serious didn't occur.

 

Be Safe. Cheers.

[Ubehage]

Shit deer!!, I'm glad to hear that it wasn't as bad as it could have been.

 

Be Safe. Cheers.

I second that. Best of wishes from me!

 

In my earlier days I did some very unsafe things. When I look back, it was mainly luck that something serious didn't occur.

Oh yeah!

I have 3 incidents behind me, that I really think I shouldn't have survived.

Sometimes luck is the only thing protecting us, when we're idiots...