Will My 12 Ga Breech Loading Blank Firing Cannon Be Illegal?

[GGaskill]

Sheesh, does it ever end?

Yes; but then it doesn't matter.

[Double D]

I don't have a lathe big enough to work from solid stock right
now, which is why I'm using various thicknesses of sleeving over
a core tube to approximate the taper and other diameter variations
of the barrel. If I can't show that the barrel is safe (by inspection,
test, or verifying what it's made of is suitable) I'll probably fire it
with no projectile a few times and use it for static display.
I can always fire it from a safe distance using a rocket (Estes)
igniter and wiring. I have some rocket igniters in a drawer in
my hobby shop.

I can also reduce the bore and put a new (seamless) inner tube in it...
maybe .50 or .69 cal... I could also ream the current bore quite a bit
and put in a new inner tube.

I think all here have been quite patient and diplomatic in offering you help in building your gun.  But we are beginning to wonder if you are listening. It is now time to be very blunt with you.

From the description you have given so far you are building a "bomb".  What you have described is not safe and will eventually fail.  

So far what you have described is nothing more than an accident waiting to happen.  If you are interested in making a safe cannon let us know. We would be more than glad to help you.

[Mark 42]

Honestly... sometimes I feel like some are not listening to what I'm saying...
or maybe it's just not coming out the way I'm trying to say it.

Sleeved barrels are not new.

Igniting with electricity is really not thinking that far outside the box.

Mark 42 -
Don't ever think we're getting down on ya.  Our responses are about issues that would do damage or incarceration.  And if you post a picture without an empty powder can in it for scale the thread may go on forever noting the fact.  

Here's a picture... not the best or clearest in the world, but it might help a little.
I'll try to measure the diameters and put them here later on.
I'm getting behind on some things and better go.


I do a pretty fair amount of engineering in situations where lives are
at stake, and there is nothing dangerous about what I'm describing...
if the right solutions to issues that have been pointed out can be
implimented.

The issue with seamed tube was one of corrosion rther than strength,
as I understood it. If the seamed tubing is protected, it won't corrode.

I haven't even said for sure that I used sleeved tubing, but if I did,
it was not near the firing chamber, and it will be protected from
corrosion. I agreed that plating would not be enough thickness to
maintain protection for the long term (unless I did a whole lot of
layers of eloctroplating).

I could go buy a kit, or go buy a bigger lathe, but I prefer to work
with what I have for now, and use it safely if possible. Id that means
no projectile and a charge of 60 grains, that's fine.

If I can find a proper way to test it, that would interest me.

But to call my work a bomb w/o seeing it first hand is a bit of a jump.
I've been welding for 30 years (not professionally), and though the
welds I did are not beautiful, they are not weak.

I'm willing to listen, and if you read what I have said, I have listened,
and have changed what I am working on quite a bit, and wil continue
to listen to suggestions... but also would like alternatives.

If I just toss away what I have at this point, it will not ever get
built. It took time to scavange heavy walled tubing at the Boeing
surplus (they don't use crap to buil things... it's quality stuff).
It took time to weld, grind, weld, grind, measure, grind, drill, etc.

I have a project that is started. It will be used for something...
maybe just to make a bang, maybe to go boom, maybe to sit
on a mantle as a decoration. But it is the only one I can build for
now, and I'd like to know how to continue building it.

I may end up deciding to make it non fireable and put a label
statinng that it's not for firing... but I'd like to figure out a safe
way to build it for firing as a signal cannon. I think it's more than
adequately strong for use without a projectile. If I can get some
numbers about the chamber pressures witthout a projectile, I can
use that to do proper analysis.

I have colleagues who specialize in materials and corrosion prevention...
if I know what the corrosives are (it sounds like acids) I can check with
them for how I can protect against corrosion.

But just because I'm not thinking inside a familiar box, don't assume
that I'm in a dangerous position... different isn't always worse.

[Cat Whisperer]

Mark -

We are listening.  It may be that for a first project that you've got just a few too many variables in the equation.

I AM SPEAKING FROM THE PERSPECTIVE OF HAVING SEEN A CANNON EXPLODE - FROM ABOUT 15' AWAY.  That was about 40 years ago.

One can design based on principles or formulas - and the proof comes way down the road after it's survived many many firings.  Not a bad method if one is experienced in the field of metalurgy or perhaps mechanical engineering.

Or one can use tried and proven designs.

Where I see you going is trying to engineer using minimal materials.  Further, several folks have tried to stear you into a safer process.

Look at other successful designs and copy one - adding a bit here and there for extra strength - over build it.

We don't want to read about it the national news.

We are playing with toys werein the pressure goes up EXPONENTIALLY when the cork gets stuck in the mouth of the bottle.

If you don't agree you might want to send a PM to Claypipe and ask his oppinion.

[Double D]

The issue isnÂ’t that you need seamless tubing for corrosion resistance. You need the seamless tubing for strength.

Welded seamed tubing can be very strong. Your brand new cannon isnÂ’t going to burst on first firing because it has a welded seam liner.

It's the very nature of welds themselves that create the problem. Welding often leaves occlusions and micro-pores in the metal. These occlusions and micro pores can collect moisture and fouling.

When fired, particles of blackpowder fouling can be blasted into the micro-pores. The expansion of the metal from pressure and heat can allow these microscopic particles to be driven deep into the metal. When a wet swab is passed down the bore the steam can further imbed this fouling as well as cause condensation with in the occlusions. Over a period of time this fouling starts the corrosion process. The corrosion process takes place in the metal. The corrosion slowly grows until it is too weak to retain the pressures applied to it. It can result in anything from pin hole leak to a catastrophic rupture.

Under normal use it's a problem that might not manifest itself for years.

ThatÂ’s what happened with many Damascus Shotgun barrels. These guns were used for years before any problems occurred. I have seen several of these burst damascus barrels and there did not appear to be any visible corrosion on the inside or outside of the barrel. One characteristic I did note, on a couple of the barrels was a darkening of the pattern of the seam in the area where an occlusion was corroding.

I can recall the first black powder cannon I built. It was made from Schedule 80 welded tubing. When the rust started to bubble the paint over the seam we tossed that tube out and built another. We never had an accident. I donÂ’t know why. We were darn lucky.

Twenty years ago when I started serious shooting and building of model muzzleloading artillery one of the first warnings I received was about the use of welded seam tubing. DonÂ’t Use it, I was told!

Back then the magazine “The Muzzleloading Artilleryman” often had articles on cannon firing accidents. Poor casting techniques, lack of liners in cast guns and welded seam tubing failures were prominent. Even back then organizations like the North South Skirmish Association knew about the weakness in welded seam liners and had rules against their use.

Here is an excert from the North south Skirmish association rules describing barrel liners for  cannons.

[Cat Whisperer]

DD - excellent!  Thanks for filling us in with the details!

Mark 42 -  keep at it!  We'll try to keep an open mind on the design process.

[Mark 42]

Just want to touch base and give some idea that I am really listening...
(and to say thnks)

DD,
I want to say thanks for posting the info. I will have to print and read
it later (lunchtime is not quite long enough), but I do want you to know
that I honestly appreciate the information and will read it carefully.

I'm doing some other research too (mostly Google type stuff on
combinations like "cannon barrel seamed pipe" to see what other
info is out there, especially if I can find some examples of failures.

If I suggest a "what if I do this" it's not that I will necessarily do it,
but just asking if it would address an issue like the corrosion.

I'm familiar with corrosion as a stress riser (crack initiation),
but hadn't though about steam pockets.

It still seems like if the seamed tubing were just an outer sleeve
and the main inner bore tubing were extruded and seamless,
the isuue would be addressed (precluding impurities getting
between the layers of tube).

Even if I decide to make this a non-firing cannon, I'm still curious
about the science and engineering involved, and whether some
of the issues that make me decide to either not fire it or to retire
it after a very short time could have been resolved by some prhaps
uncommon solutions (maybe even new or innovative ones).

Don't write me off as a stupid future victim of natural selection just
yet... I may be a little crazy :eek:, but if I were truly stupid I wouldn't have
come here to find out more in the first place.

Consider a lot of this as possibly a thought experiment or just scientific
curiosity that could lead to an experiment, but might not.

I'll be careful, and will keep reading and learning.

And I do mean it when I say I appreciate the guidance, and I'm not
ignoring it.

[Double D]

I'm doing some other research too (mostly Google type stuff on combinations like "cannon barrel seamed pipe" to see what other info is out there, especially if I can find some examples of failures.

Please post your findings with links for all of us.

It still seems like if the seamed tubing were just an outer sleeve
and the main inner bore tubing were extruded and seamless,
the isuue would be addressed (precluding impurities getting
between the layers of tube).

This one way to it.

I can not urge you strongly enough to acquire a copy of Switliks book The More Complete Cannoneer .  Anyone one shooting or building cannons who  doesn't have a copy of this book is short changing themselves.  You will find a link to it in the Cannon resource list a the top of the board.

Don't write me off as a stupid future victim of natural selection just
yet... I may be a little crazy :eek:, but if I were truly stupid I wouldn't have come here to find out more in the first place.

We don't intend to allow anyone visiting this board to receive the Darwin Award, not even honorable mention.

[Mark 42]

Thanks.

I'll look into the book... it sounds like it discusses cannon design & building,
which would be a book I'd buy (unless it's quite expensive).

I'll definitely post what I find.
I've been known on other boards as "Linkmeister", so you can expect
links to relevant info. You may have noticed a link or two amongst
the posts I wrote earlier in theis message thread.

It may not be real soon, but I expect to get some research (before
I finish or fire anything I build).

[Mark 42]

Sheesh, does it ever end?

Yes; but then it doesn't matter.

Ah yes... Some Day

[Mark 42]

If this post looks disjointed or hard to follow, it's partly
because I'm writing it offline first in short bits as time
permits, so I may lose my place or revise my train of though
as I write it.

Is there a difference between "the Complete Canonneer" and "The More Complete Cannoneer"? It looks like "More" is just a newer
edition. I'll probably order it soon since it's not all that expensive,
and appears to have tons of useful info from what I'm hearing so far.

BTW, I didn't see it listed on the "References" sticky-post.

I did find it at Amazon.com, and it looks pretty affordable.

I have re-read this message thread and realize that I either misread or
misinterpreted a few things that became clearer once I re-read them in
conjunction with some of the later posts. Found a few typos too...
will eventually go back & fix them and revise some unclear sentences
as well, if I still can edit them.

Here's the way I understand the discussion so far...

Seamed pipe should never be used for the bore of the barrel
because the weld is porous and gives opportunity for impurities
from the combustion of the propellant to penetrate into the metal
and create stress risers for cracks to initiate (corrosion stress
cracking... a type of metal fatigue).

Water pipe is made of weal material in adition to being seamed,
and should not be used for any of the barrel including outer sleeve
layers.

Some seamed tube types may be strong enough for use for outer sleeve
layers in conjunction with a solid extruded sleeve in the inner
layer which includes the bore of the barrel. The key is determining
if the seamed tube is strong enough, and keeping it isolated from the
corrosive combustion environment.

A solid steel barrel made from solid rod or from extruded seamless
tubing of adequate wall thickness and strength (material) or from
a solid extruded steel tube bore liner of adequate strength and thickness
with an outer barrel of solid iron, steel or bronze (brass?) is generally
considered sound design practice.

The wall thickness in the breech / chamber area should be equal to the
caliber (O.D. = 3x Bore). This would mean an outer diameter of 9" for
a 3" bore, or 5-1/4" for a 1-3/4" bore (Golf ball). For my .810 bore
I should have about 2.43 (2-7/16)" O.D. The bottom of the bore in the breech
plug should have a smooth radius at the base of the bore equal to 1/8 of the
bore diameter (rather than a blunt bottom). This makes sense for two reasons:
sharp corners are stress risers and are also difficult to keep clean.

I looked at the excerpt from the North south Skirmish association (NSSA?) rules,
and it led me to a question:

It said certain barrels should be lined "with a bore liner of extruded seamless
tubing of a minimum ANSI standard", but that leads me to ask which ANSI
standard, or is it just any ANSI spec steel is acceptable?

This can be tough to determine when I'm buying surplus steel... which is
far less expensive, and often is even superior to what is commonly available
from more conventional sources.

Another question I have is about joining tubes... I have some joints
that are welded in a ring, but the joint is only the inner or the
outer tube at any particular location... never are both tubes joined
at the same place (the tubes overlap legthwise). I think it would be
best to go ahead and add one continuous inner liner from breech to muzzle
so that none of those welds are exposed to combustion gasses and other
corrosives. The example breech in the NSSA excerpt does have some of
the joint exposed to combustion chamber, but it is sweated at the
joint, which is what I did between layers of tubing (some of what I'm
calling tubing is machined steel; I use "tubing" as a generic term).
I'm just curious about the philosophy of the design of the joint.
The breech plug I intended to use is actually a 1-1/2" dia. bolt,
welded into a 1-1/2" nut to form sort of a cap nut arrangement.
I can add the radius at the back end by brazing... much like the
example.

I'm thinking if I drill out the bore to 7/8" or even 1" and then put
a tight fitting solid steel tube liner with a commonly used bore (caliber)
that is somewhere in the range of .45 to .75"

I think I saw a couple of links to info about proof testing in a
message thread in this forum somewhere. That interests me. The only
problem I see with proof testing is "how do you know you didn't
damage the barrel in the test?" Just because it didn't shrapnel
doesn't mean it really survived the test. I suppose one could
do a dye penitrant (or magnaflux) test after the proof test.

I could do a proof test safely, but interpreting the results
is not so straightforward, I would suspect. I'd like to hear
opinions on proof testing.

I may very well start over, and relegate the tube I have started
to static display, but I still would like to see if I can't
find a way to ensure that it is safe and to subsequently fire it.
I'll probably only fire it a few times per year with no real
projectile, so it won't get a lot of significant hard use (Unless
my 24 ft sailboat gets pressed into naval service).

I'm continuing other research.
Here are some links I've found interesting &/or useful... I suspect
most of them y'all are already aware of.

Cannon Mania's info page
http://www.cannon-mania.com/black_powder.htm

Amazon has "The More Complete Canoneer"
http://www.amazon.com/exec/obidos/tg/detail/-/B0006EXZCK/qid=1129836019/sr=8-2/ref=sr_8_xs_ap_i2_xgl14/103-5427950-4080664?v=glance&s=books&n=507846

Cannon Safety:
http://www.museumandcollector.com/cannonsafety.html

A bit of info, part of which (Armstrong Gun) explains why multi
layers of tube are strong (probably similar to use of laminates in other
load bearing designs):
http://www.civilwarartillery.com/glossary/glossary.htm

Building a mountain howitzer:
http://www.buckstix.com/HowitzerBarrel.htm

Army Ordnance Manual:
http://www.hti.umich.edu/cgi/t/text/text-idx?sid=9a67ac609d058d0c6e126d8a702aafe5;c=moa;iel=1;view=toc;idno=AGY4347.0001.001

Some interesting links:
http://www.museumandcollector.com/

I haven't found a lot about the seamed tubing issue on other
sites (I'm continuing with other search keyword combinations)
I have seen some interesting message threads here in the forums,
and am now beiginning to compile links so I won't say to myself
"Now where did I see that" (Like the proof testing links post):

Here's the first so far (I'm out of time for now):
http://www.graybeardoutdoors.com/phpbb2/archive/o_t__t_5957__start_0__index.html

[Double D]

Is there a difference between "the Complete Canonneer" and "The More Complete Cannoneer"? It looks like "More" is just a newer edition. I'll probably order it soon since it's not all that expensive, and appears to have tons of useful info from what I'm hearing so far.

Complete is the first edition.  More Complete is the latest edition  and well, more complete.

BTW, I didn't see it listed on the "References" sticky-post.

You will find it listed in Where to find Blackpowder Cannons and shooting supplies.  This was our premier Board sticky. The others came later and contain other related  subject matters.

Seamed pipe should never be used for the bore of the barrel
because the weld is porous and gives opportunity for impurities
from the combustion of the propellant to penetrate into the metal
and create stress risers for cracks to initiate (corrosion stress
cracking... a type of metal fatigue).

Never is to strong.  Not recommended is better.  Use recognizing limitations is good also.  Use only the higher quality welded seamed pipe and take preventive measures if used.  Seamless is safer.

Water pipe is made of weal material in adition to being seamed,
and should not be used for any of the barrel including outer sleeve
layers.

Waterpipe can be used for decorative outer shell as long as your inner part is strong enough and you prevent black powder gases from getting between the layers..  

Some seamed tube types may be strong enough for use for outer sleeve
layers in conjunction with a solid extruded sleeve in the inner
layer which includes the bore of the barrel. The key is determining
if the seamed tube is strong enough, and keeping it isolated from the
corrosive combustion environment.

Should you follow the recommended dimensions for a barrel liners the strength of the outer layers are not critical.  Their strength is added to the liner.  I believe the engineering principle is called lamination. It was a constantly applied principal widely used through the muzzle loading cannon era.  Many of the the derogative bands you see on cannon are metal bands sweated onto the cannons dor strength.  The most obvious is the big breech ring around the breech section of Parrot rifles. That is separate piece sweated in place.

A solid steel barrel made from solid rod or from extruded seamless tubing of adequate wall thickness and strength (material) or from a solid extruded steel tube bore liner of adequate strength and thickness with an outer barrel of solid iron, steel or bronze (brass?) is generally considered sound design practice.

Yes

The wall thickness in the breech / chamber area should be equal to the caliber (O.D. = 3x Bore). This would mean an outer diameter of 9" for a 3" bore, or 5-1/4" for a 1-3/4" bore (Golf ball). For my .810 bore
I should have about 2.43 (2-7/16)" O.D. The bottom of the bore in the breech plug should have a smooth radius at the base of the bore equal to 1/8 of the bore diameter (rather than a blunt bottom). This makes sense for two reasons:  sharp corners are stress risers and are also difficult to keep clean.

The wall thickness in the breech / chamber area should be no less than equal to the caliber (O.D. = 3x Bore).

Keep in mind that this applies to the chamber/ breech area only in cannons.  I howitzers and mortars the powder chamber is the breech/powder chamber and is smaller the the bore for the projectile.

d at the excerpt from the North south Skirmish association (NSSA?) rules, and it led me to a question:
It said certain barrels should be lined "with a bore liner of extruded seamless tubing of a minimum ANSI standard", but that leads me to ask which ANSI standard, or is it just any ANSI spec steel is acceptable?

ANSI spec for  seamless steel tubing.

Another question I have is about joining tubes... I have some joints
that are welded in a ring, but the joint is only the inner or the
outer tube at any particular location... never are both tubes joined
at the same place (the tubes overlap legthwise). I think it would be
best to go ahead and add one continuous inner liner from breech to muzzle so that none of those welds are exposed to combustion gasses and other corrosives.  

As long the welds are not in the bore. The potential weakness is in the weld itself.

The breech plug I intended to use is actually a 1-1/2" dia. bolt,
welded into a 1-1/2" nut to form sort of a cap nut arrangement.
I can add the radius at the back end by brazing... much like the
example.

Actually a screw in breech plug is not a bad idea if made right.  I have made breech plugs much like those found in muzzle loading rifles. The breech plugs I made screwed in and a had a pin on the bottom of barrel to hold the plug.  the plug could be remove with a spanner wrench for cleaning.

Cosmetically the bolt would be ugly. It will need substantial machining to fit and work right, but it's not impossible.  But you can do better.

I'm thinking if I drill out the bore to 7/8" or even 1" and then put
a tight fitting solid steel tube liner with a commonly used bore (caliber)
that is somewhere in the range of .45 to .75"

One thing that hasn't been discussed is how you will bond the outer sleeves to the inner sleeves.  The More Complete Cannoneer discuss this issue.  

I may very well start over, and relegate the tube I have started
to static display, but I still would like to see if I can't
find a way to ensure that it is safe and to subsequently fire it.
I'll probably only fire it a few times per year with no real
projectile, so it won't get a lot of significant hard use (Unless
my 24 ft sailboat gets pressed into naval service).

Read the More Complete Cannoneer first then make you decision

Let us know if you find any cannon link that we don't already have on Where to find Blackpowder Cannons and shooting suppliesor References and we will add them.

[Mark 42]

Let us know if you find any cannon link that we don't already have on Where to find Blackpowder Cannons and shooting suppliesor References and we will add them.

Thanks.
I'll spend more time with those.

So far I have been brazing the layers together by flowing brass between them,
a lot like the way copper pipes are soldered by plumbers.

I'll go do some reading... may not be back for awhile.

[Mark 42]

I did buy The More Complete Cannoneer[/b], but haven't read a lot of it yet.
My cannon project sort of ground to a halt because of other "must do"
projects interfering (too many power windows to repair!).
I do see my cannon barrel almost every day, and got an urge to work
on it this weekend, but I have a higher priority project that prevented
me from getting wrapped up in enjoyable projects (I haven't been
out to check on our boat since September, and the mooring hardware
is now 3 years old & the rainwater in the bilge has had ample time
to grow algae and start rotting the cabin subfloor structure).

I may give up and start over with a better barrel blank. It's all back on
my "someday" projects list for now. Maybe when my kids are older and
I stop getting sucked into their activities.

[Double D]

Posted so far off topic that they never even should have been considered to be posted here...deleted!!!