A new cannoner

[Titus]

Steel melts at more than 1300 C.

Cannon Caster, steel pipe is made from mild steel meaning it has a low to medium carbon content and it actually begins having viscous properties at just above 800C. Blade steels like 12C27 and N690 which even has other metals like chromium, vanadium, molebdenum, manganese and silicon as well as a high carbon content has high heat tolerances. We harden our blades at 1080C. I will include a pic so that you can see what they look like at that temp. Its very cool. Cast your barrels, but get them reamed to ensure uniform bores. Cannons are lots of fun, but they are not toys. They can kill. Remember safety first.

Hmmm... Somehow "Safety first" isn't what comes to mind when I see a half naked man dangling a white-hot piece of steel over a small quenching tank with a pair of very short pliers.

I know, I know - he's an expert and has been doing it that way for over 40 years...

Victor, I understand and agree with your point, HOWEVER, if you've ever done any hardening of blades you'd know that first of all, this is a fast moving business. You have to work accurately and (stupid as it may sound to you) all kinds of gloves and long sleeved clothing really hampers the required free movement. Anyone who thinks otherwise is welcome to practice another hobby. Yes, accidents can and do happen, but there are CALCULATED risks that you are willing to take in anything you do in life. For example, getting in you car and driving to work is much more dangerous than what you see in this picture (whether you think so or not), but you have taken a calculated risk. You have been driving for many years, but still you never know if you are going to be in a fatal accident around the next corner. Many things (beyond your own control) can go wrong but you trust that they wont. If they do, you might lose your life.

Secondly, a burn from one of these pieces of metal will scar you for life yes, but can hardly be compared to an exploding cannon tube which will kill you (which my reply was about and to show cannoncaster what steel looks like at 1080C).

Back to the topic.

[Victor3]

 Titus,

 The reason I responded as I did to the picture that you posted is because I am keenly aware of the risks associated with industrial processes, including heat treating.

 One of the hats that I wear on my job involves risk assessment & management, accident investigation, preventive/corrective actions, and as can be seen from my recent post below, occasionally the wiping up of blood...

http://www.gboreloaded.com/forums/index.php/topic,140073.0.html

 The gentleman in your picture is violating several well established safety rules (to his peril) that would not be tolerated in any manufacturing company (at least in the US) if the company cares to stay in business for long. OSHA and workers comp carriers do not value "fast moving business" over the safety of employees.

 Neither do I. I've been involved with enough industrial accident investigations by now to know that production requirements are never an excuse for a blatant disregard of safety concerns.

[Titus]

Victor I acknowledge your experience and decorations in your profession, however, its a matter of perspective. If someone wishes to not keep to OHASA rules and regulations in his own garage, I believe thats his prerogative to do so.

Lets agree to disagree.

[Cat Whisperer]

another very important factor is ductility of the metal.

Right on the money!  It is the repetitive hammering that makes the metal go more and  more brittle, until - all at once it fails.

Hence, it was the discovery of what we now call MILD STEEL (such as 1018 and many others) that totally revolutionized the cannon making industry world wide in the second half of the 19th century.  Not as glamorous as the modern steels, nor as easy cutting as some of the re-sulpherized and leaded steels, but they have the key characteristics needed in this application.

THEN there are TWO more ingredients in the mix - good design and proper loading.

[Cat Whisperer]

Re: the picture.

Y'all may DO what you want.  Posting the picture as it is is one of those things.

But since SAFETY is one of our FIRST concerns, please note the safest behaviors and practices possible if they are not practiced in the picture. 

That is OUR minimum responsibility to others that may follow our example.

I have posted pictures in the past, when I - upon thinking about what I'd just posted - noted serious safety violations.  Pointing them out makes it a teaching tool.

We can agree to disagree, but the above will be done. 

(Let's not get off on discussing motor cycle helmet laws either.)

[Cannon caster]

No here I am. Still alive with all parts attached. Only I was distracted from canon hobby for some time but I am back now. The problem is that now I have school afternoon now instead in the morning so I have very little time. I can wait summer to have more time for things I like The problem is I cant fire cannons very much as there are too much people and especially tourists so I someone could report it to the police

[Cannon caster]

As everyone here knows black powder based on potassium nitrate is used in cannons here. But isn't black powder based on sodium nitrate faster burning (sodium is weaker bonded to the NO3 anion than potassium as far as I know so it gives up its oxygen easier)? I know that NaNO3 is hygroscopic but I believe that is not the only reason it is not used in cannons. And you need less of it to make good powder as sodium is lighter than potassium so NaNO3 contains more oxygen per mole than KNO3. So why isn't it used in black powder for cannons? I know it is used in blasting grade BP (or used to, BP isn't used much for blasting to day as far as I know).

NC isn't used in the types of cannons disused here as it is "too powerful" But I have seen a video of a cannon made from a hydraulic pipe that used 200 g of NC primed with 30 g of a KBrO3/S/sucrose mixture. The man who did it calculated the golf ball fired from that cannon traveled around 10 km!! Here is the link. http://www.powerlabs.org/cannons.htm

But how about other fuel/oxidizer mixtures? I have successfully used a mixture of KClO3 and C6H5COONa (70:30) in a small home cast brass cannon. In my experience this mixture is very "powerfull" perhaps too much to be safely used in large cannons. I think that potassium permanganate and sulfur could also be used but after several attempts I still didn't find the optimal ratio that burns fast enough. Adding fine flake Al powder increased the "power" very much (similar to flash powder). Perhaps too much to be safely used in cannons. But I think that it could be used in small thick walled model cannons. Amonpulver is also interesting. It is a mixture oh NH4NO3 and charcoal in a ratio approximately 85:15. It was used in some large caliber cannons as it is supposedly relatively slow burning. When I purify some more AN I will try to make that mixture to see how it burns. A mixture of KClO3 and Al powder (70:30) is a very "powerfull" mixture but I don't believe it is useful in cannons as it burns too fast and doesn't have any gasses as deflagration products. A mixture of KClO3 and sulfur is too unstable to be used (spontaneous ignitions have happened). Perhaps the smoke bomb mixture also known as rocket candy could be used. It is a mixture of potassium nitrate and sucrose (60:40 with sometimes a little Fe2O3 added to increase the burn rate). The 60:40 ratio is optimized for smoke production but I believe that the ratio could be changed and that perhaps this mixture could be usable in cannons.

If you have any more suggestions please post

[KABAR2]

Cannon caster,

Although chemistry is an interesting area, I think you'll find that most of us on the board
use factory made black powder, experimentation with these compounds is best left to the
professionals there are too many Grey areas one can get themselves into legally, also discussing
compounds like this could lead to other young people experimenting and causing untold damage
to themselves or others, I would stick to discussing cannon and their construction.

Allen <><
 

[GGaskill]

NaNO₃ is not used in sporting black powder because it attracts moisture faster than does KNO₃.  The moisture degrades black powder quickly.

[Cat Whisperer]

All -

We have here a very interesting start of an examination of what goes into potential propellants.

Let me respond to one or two of the questions.

First of all OUR prime concern here is SAFETY.  Hence, our recommendation of using nothing other than proven loads in known good quality cannons/mortars using accepted standard safety procedures.  (of note oft mentioned Mr Switlick: More Complete Cannoneer; N-SSA and AAA published procedures.)

That being said, let me emphasize that one must recognize that any experimentation should be done under guidance from folks that have professional experience in the area.

The reason is simple - pressures can easily go straight up well past the limits with a minor change in chemistry, loading or other factor.  That should DICTATE VERY careful procedures under controlled circumstances - overseen from someone with EXPERIENCE.

Let me just say (again) there were several YEARS that I knew I'd not live until I was 21 - ....  I'm 60 now and admit that I got away with a lot.  

I remember something about 'blasting powder"  - Don't know much more about it - other than my step-dad got it from the quarry (in a quart mason jar).  From what I've heard (OK - take that as HEARSAY!) it is gentler - so that it won't shatter the rock.  In any case the pressure curves ARE different.  (Let me also say that I think (it was 45 years ago) that that WAS the propellant used when the cannon exploded.)

SO, let's all do the homework.  FIND examples of what you might consider using; examples that are well documented and accepted as good practice.

Also, to keep in tune with the scope of this board - lets keep to either the currently commonly accepted practices (as noted before) or the historical development of conventional propellants.  

I don't mean to be overly restrictive here.  But I do wish to keep a couple of things clearly in the forefront of our activities - #1 is safety, #2 is keeping within the law (federal, state, local and this forum).

Some discussion of the chemistry and burning characteristics of black powder propellants is certainly well within the scope of this forum.  Propellants other than conventionally used ones will be considered for discussion of burning characteristics on an individual basis but certainly should not be considered as acceptable propellants for discussion here until proven by widespread acceptance.



 

[Terry C.]

Jugoslav, not being from this country you may not appreciate the situation here. Certain events have placed experimentation with volatile chemicals in a very suspicious light. The situation has the potential to become even more unfriendly in the near future. Regulations have already been tightened on some chemicals with more to follow I'm sure.

Part of the deal that keeps this hobby alive and in good legal standing in the USA, is the fact that the Federal regulations are still (at least for now) relatively lenient towards the sporting use of black powder.

Homemade experimental explosive concoctions are another matter entirely. For this reason, discussions of this nature are a bad idea.

[dan610324]

even if Im from sweden I couldnt agree more to that , all those experimental ideas just show your ignorance against safety and common laws

[Cat Whisperer]

...
 ignorance against safety and common laws

Which is one of the BEST reasons for DISCUSSING these issues.  Learning comes from comparing what we think to what others think and sorting out what is valid and what is not.

Hence, LOTS of discussion is good, provided it is detailed and thorough in examination of the issues and involves knowledgeable folks.  (and of course within the scope of this forum)

For example, there are some VERY interesting features of the comparisons of how black powder burns compared to how smokeless powder burns and the resultant differences in pressure curves.

[Cannon caster]

Jugoslav, not being from this country you may not appreciate the situation here. Certain events have placed experimentation with volatile chemicals in a very suspicious light. The situation has the potential to become even more unfriendly in the near future. Regulations have already been tightened on some chemicals with more to follow I'm sure.

Part of the deal that keeps this hobby alive and in good legal standing in the USA, is the fact that the Federal regulations are still (at least for now) relatively lenient towards the sporting use of black powder.

Homemade experimental explosive concoctions are another matter entirely. For this reason, discussions of this nature are a bad idea.

I understand. So in US It is not a good idea to do experiments as you are then thought as a drug cook or terrorist. Where I live things are different. Shooting cannons of any type is against the law. Powder cant be legally bought without special licenses. But experimentation with small amounts of pyrotechnic mixtures and explosives while illegal is tolerated by the police. So I am forced to make my black powder. Since it is not easy to make high quality powder without a ball mill I am looking for other mixtures that are also safe to use but perhaps can be made with less effort than BP (which I never succeeded to make in the same range as ball milled powder).

[dan610324]

you dont need an ball mill to make an good quality bp .

use an old fashion mortar , not the type dicussed in this forum , but the same as your grandma use in the kitchen . pulverize all 3 components very carefully separately ,
mix each component with pure alcohol  , wait a few days and stir it carefully a few times a day , then mix it and put in on an smooth surface to dry , then mill it and make different size fractions .
it maybe aint exact same quality as an commercial bp , but very close to it

[KABAR2]

you dont need an ball mill to make an good quality bp .

use an old fashion mortar , not the type dicussed in this forum , but the same as your grandma use in the kitchen . pulverize all 3 components very carefully separately ,
mix each component with pure alcohol  , wait a few days and stir it carefully a few times a day , then mix it and put in on an smooth surface to dry , then mill it and make different size fractions .
it maybe aint exact same quality as an commercial bp , but very close to it

Adding graphite to the mix also aids in keeping the granuals from going POOF! when being broken down from cake form. it should still be done in small amounts.

[dan610324]

do you mean that bp produced that way can self ignite ??

35 years ago when we did bp we just used an marble mortar to crush it to an  smaller fraction .
we had no idea that it could be dangerous .

maybe Im lucky to sit here today then .

whats the difference between with and without graphite ?? how does it protect the bp from self ignition ??

if adding graphite , how much ?? and when ??

Ive heard that there are polished and not polished bp , whats the practical difference ??
I don't even know if my German bp is polished or not .

no I got no plans to start producing bp again , Im just curious . knowledge is an easy burden .

[Cat Whisperer]

do you mean that bp produced that way can self ignite ??

35 years ago when we did bp we just used an marble mortar to crush it to an  smaller fraction .
we had no idea that it could be dangerous .

maybe Im lucky to sit here today then .
...

I knew a fellow (when I was in HS) that made a BATHTUB FULL of black powder - mixing it all with a shovel !

He used a window screen to get all the particles the right size.

If it had gone off the whole house would have disappeared !

[dan610324]

probably not only the house , more likely the whole block .
we never made any larger than 2 pound batches , and we used an turned wooden stamp in the marble mortar .
then we used 2 different sizes of mosquito net to separate different granulation ( fractions ) .
first one with larger holes in it , maybe 1,5-2 mm
anything that didn't pass the net we took back to the mortar again , when everything passed the first net we used one with smaller holes , approximately 0,5-0,75 mm .
anything stayed on top of that net we used as gunpowder , the other leftovers that was to small we used for fire crackers .
approximately 1/3 was gunpowder and 2/3 was firecracker powder .
it was a lot of noise making here in the village those days   

we used empty toilet paper rolls , thick cork and dynamite fuse , that kind who got an black surface from tar .
first we drilled one cork with an 4 mm drill bit and put the fuse there , fuse is approximately 6 mm , then glued the bottom cork in position , filled up with approximately 75 - 100 gram bp , glued the other cork into other hole , pressed them together in an vise .
then we reinforced the outside with an 2 component plastic and fiber glass .

that's what I call real fire crackers   
toilet rolls are approximately 1 3/8" x 10 1/4" , finished they was 2"x11"
with an 5" fuse we had 12 - 15 sec before they detonated
we also used them for fishing    we was to young to have any dynamite   
but in a few years time that also changed