Author Topic: How to blow up a cannon (Read 9606 times)

RocklockI · « **Reply #60 on:** September 17, 2009, 08:35:20 PM »

well ......believe it or not ...i'm speechless ......and thats sayin something !

i'll get over it of course ........tomorrow .........

Cat Whisperer · « **Reply #61 on:** September 18, 2009, 12:52:02 AM »

That's one of those episodes that fits into the category: "it seemed like a good idea at the time."

Glad y'all survived it. Those are memorable events, hopefully not tragic.

Double D · « **Reply #62 on:** September 18, 2009, 01:51:40 AM »

The dangers of short seating are very real and greatly exaggerated. You should not as a practice leave excessive airspace in a load. The small amount of airspace that is left in a cannon barrel when a ball is full seated is not harmful.

If the ball can not be fully seated because of fouling or other interference, then a danger exists.

armorer77 · « **Reply #63 on:** September 19, 2009, 03:13:46 PM »

Ok , here it is , the final shot in this test .

The Naked Gun 44mm

This time I added 200lbs. of lead to the base .

The load , 1100 grs of 4Fg BP under 5 1lb. lead balls

AS you can see my tube survived .

My test base didn't

The trunnions are intact

With only minor damage . No cracks were visible , even after a dip in acetone . Armorer77

Cat Whisperer · « **Reply #64 on:** September 19, 2009, 04:21:26 PM »

Evidence that overbuilding or using good rules-of-thumb is GOOD.

It's a good half of the equation. Part of the rest of it is firing a 1000 times with moderately overloaded charges - but who has the time?

This is good news for that 'accidental' overcharging.

Victor3 · « **Reply #65 on:** September 19, 2009, 08:50:01 PM »

Wow. It lives

One rule of thumb should be "It's dang hard to beat solid steel for safety in a cannon barrel."

I doubt that a cast iron barrel of similar dimensions with a 3/8" wall steel liner would have withstood 1/2 of that load.

dan610324 · « **Reply #66 on:** September 19, 2009, 11:48:05 PM »

it would be very interesting to see if any manufacturer of cast iron would dare to do such an test
or even with a sleewed cast iron barrel
I guess they just dont dare to do it
or at least not show the result as open as you have done it here

but you have for sure showed the quality of your pieces
with normal charges of fg and one ball there can probably never be any accident with your barrels
if they dont point it in a stupid direction

you have really try to have it blowing apart now
without any success

you are a low scum of the earth demolition man
but a he-l of a cannon builder

I guess that its not possible to do it better then you do

armorer77 · « **Reply #67 on:** October 10, 2009, 08:07:23 AM »

I have decided to accept the 1000 shot challenge . 43 down 957 to go . On my budget it should only take about 5 years . I will get back to you as I progress . Armorer77

dan610324 · « **Reply #68 on:** October 10, 2009, 08:36:21 AM »

hehehe WOW

YOU GOT TO BUILD YOURSELF A BACKSTOP THAT YOU ARE ABLE TO RECOVER THE BALLS

5000 lbs of lead is expensive

subdjoe · « **Reply #69 on:** October 10, 2009, 09:41:09 AM »

Quote from: dan610324 on October 10, 2009, 08:36:21 AM

hehehe WOW

YOU GOT TO BUILD YOURSELF A BACKSTOP THAT YOU ARE ABLE TO RECOVER THE BALLS

5000 lbs of lead is expensive

Hmm.....if he were to to take some heavy wall pipe, and curve it around just right....

Cat Whisperer · « **Reply #70 on:** October 11, 2009, 03:13:47 AM »

Quote from: armorer77 on October 10, 2009, 08:07:23 AM

I have decided to accept the 1000 shot challenge . 43 down 957 to go . On my budget it should only take about 5 years . I will get back to you as I progress . Armorer77

I'm impressed! It would be interesting at least to log the temperature and a few key measurements to make comparisons as life testing progressed.

armorer77 · « **Reply #71 on:** October 15, 2009, 10:28:09 AM »

Hi , I would like to see a comparable test of a cast and lined barrel . Any other makers willing to put their barrels to the same test ? This week end I am going to do accuracy testing . My 12" Parrot smooth bore with an aim point sight . The range will be 100 yds. I will post results and photos Sunday morning Armorer77

dan610324 · « **Reply #72 on:** October 15, 2009, 11:35:45 AM »

I dont think anyone who make cast iron barrels ( sleved or not ) would dare to come even close to your loads
but I sure hope some of them reads this
I wouldnt do it with a cast bronze barrel , I think

well I cant either as I never made any such large diameter bore

armorer77 · « **Reply #73 on:** October 15, 2009, 11:45:59 AM »

Thanks for the input , I agree a bronze barrel is not a comparable test , bronze has it's own beauty but steel has more stregnth . Armorer77

dan610324 · « **Reply #74 on:** October 15, 2009, 12:05:32 PM »

dont be so sure of that

ratings are :

cast iron = 40 000 psi
mild steel = 60 000 psi
bronze = 65 000 psi

so it depends on what steel quality you use

armorer77 · « **Reply #75 on:** October 15, 2009, 12:19:06 PM »

Good point , but , I don't know how to cast bronze yet .And I must stress "yet ". Armorer77

dan610324 · « **Reply #76 on:** October 15, 2009, 12:28:03 PM »

bronze casting isnt that difficult, it just take some common sense , the right equipment and a year of internet studies to learn from others mistakes
when I started it was more difficult to find any good information
so it was the trial and error method for me
and it was a LOT of errors

Cannoneer · « **Reply #77 on:** October 15, 2009, 02:08:35 PM »

Quote from: dan610324 on October 15, 2009, 12:05:32 PM

dont be so sure of that

ratings are :

cast iron = 40 000 psi
mild steel = 60 000 psi
bronze = 65 000 psi

so it depends on what steel quality you use

I don't know Dan, this is just what might be called an intuition on my part, but I've got the feeling that if Armorer's field tests were conducted on a bronze barrel made to be identical with his barrels specs, that right now we'd be looking at a barrel that displyed a profile which had been drastically altered.

GGaskill · « **Reply #78 on:** October 15, 2009, 02:33:30 PM »

There are some bronzes that are that strong but 10/90 tin bronze is not one of them.

"UNS C95400 Aluminum Bronze is the most popular, all purpose aluminum bronze alloy. It provides high yield and tensile strength, good ductility, weldability and exceptional resistance to wear, fatigue and deformation under shock or overload."--Anchor Bronze website.

There are others listed on my home computer which I will list when I have the chance.
OK, the chance has come.

C94700HT--Nickel, tin bronze (HT means heat treated so there is likely some post-casting activity needed)

C65500--Everdur (this may or may not be a castable alloy)

armorer77 · « **Reply #79 on:** October 15, 2009, 03:03:55 PM »

One of these day's I will get rich enough to buy a bar of bronze to turn to a comparable tube , but not for a while . $154.04 + S+H for a 3" x 12" bar of 485bronze . {yeild strength 53,000 psi } Armorer77

dan610324 · « **Reply #80 on:** October 15, 2009, 10:26:26 PM »

BoomJ
of course it would be, if you can find the pieces

but you cant take for granted that steel is stronger then bronze

the old 90/10 alloy is far from the strongest bronze, but for me its the one and only I would use for a cannon barrel as its the classical composition

today there are a lot of better suited bronzes , maybe Im crazy , but I like to know that my barrels are made of a classic alloy

the 90/10 isnt easy to cast either

I have actually been thinking of to try the gunmetal , 88/8/4 , copper/tin/zink
but there is something inside me who say no, dont know why , maybe its because its a "modern" alloy
with the 4% zink it will be much easier to cast , and stronger

Cannoneer · « **Reply #81 on:** October 16, 2009, 12:54:34 AM »

It sure would be one heck of an interesting comparison test to witness. The loads could be more gradually increased with the bronze Parrott barrel, so as to gauge at which point the barrel first started to show signs of a buldge, or split.

Victor3 · « **Reply #82 on:** October 16, 2009, 01:04:24 AM »

Quote from: dan610324 on October 15, 2009, 10:26:26 PM

I have actually been thinking of to try the gunmetal , 88/8/4 , copper/tin/zink
but there is something inside me who say no, dont know why , maybe its because its a "modern" alloy

If you decide to go with the zinc, I'll never tell

dan610324 · « **Reply #83 on:** October 16, 2009, 09:04:03 AM »

still dont think I will do it

armorer77 · « **Reply #84 on:** October 16, 2009, 09:17:59 AM »

I am a much a traditionalist as anyone , but I am not adverse to an improved alloy if it contributes to safety . Armorer77

dan610324 · « **Reply #85 on:** October 16, 2009, 10:49:41 AM »

I prefer to reduce the bore a little to get a stronger cannon
but if you want a serious shooter in a large caliber you should use steel
for a target shooting (25 yards) small scale model bronze is a good choice
and it can be beautiful also, or for a firecracker cannon
but its too many hours in the manufacturing to have them commercial available I think
at least if you want a perfect result on an ornate piece
plain barrels aint beautiful enough in my opinion, now I will probably be killed

RocklockI · « **Reply #86 on:** October 16, 2009, 11:32:54 AM »

Quote from: dan610324 on October 16, 2009, 10:49:41 AM

I prefer to reduce the bore a little to get a stronger cannon
but if you want a serious shooter in a large caliber you should use steel
for a target shooting (25 yards) small scale model bronze is a good choice
and it can be beautiful also, or for a firecracker cannon
but its too many hours in the manufacturing to have them commercial available I think
at least if you want a perfect result on an ornate piece
plain barrels aint beautiful enough in my opinion, now I will probably be killed

I agree . One time ,months and months ago ,I 'suggested' silicon bronze because it is avalible . Dan has just a tad of Drill Instructor in him . I didnt know they made red font that big .

so I went out and found a souce of scrap copper and ingots of tin thru the inet .

Dan says it ,that makes it so .

GGaskill · « **Reply #87 on:** October 16, 2009, 02:06:49 PM »

Actually my half scale mountain howitzers are silicon bronze. There have been some statements that silicon bronze is brittle but my experience with it is that it is pretty soft, not hard. It certainly isn't a real strong alloy (order of magnitude the same as 90/10) but I doubt it would fail in a brittle mode. One just has to keep the powder charge and shot weight in proper relation. One can always put too much powder in anything.

dan610324 · « **Reply #88 on:** October 16, 2009, 07:00:05 PM »

yes its possible to overload anything , and as an oposit you can use anything as long the loads are proportional to the material used .
a perfect example of that is the wooden mortars used in the cw , or the swedish leather cannon also if those ones wasnt any big success

but at least they functioned good enough to see service

Victor3 · « **Reply #89 on:** October 16, 2009, 09:37:23 PM »

Quote from: GGaskill on October 16, 2009, 02:06:49 PM

Actually my half scale mountain howitzers are silicon bronze. There have been some statements that silicon bronze is brittle but my experience with it is that it is pretty soft, not hard.

Did you have much porosity in your barrels?

I've bored out a lot of professionally cast silicon bronze (997 white tombasil) cored sand castings and found that quite a few had significant porosity.