PDA

View Full Version : Blackpowder ignition problem with a model cannon


sam0812
December 17, 2009, 04:48 AM
Hi All .Im new to all this so please be kind. Ive got a small cannon[15 inch long-9/16 bore] with a 5/64 dia touchhole. I make my own BP which works great but I cant get anything to burn down the touchhole to set it off. Ive tried loose meal powder,various home made fuses,different mixes of powder etc. The touchhole seems to foul before the flame gets to the charge. Ive got it to fire a couple of times quite well,but its just to inconsistent.Any Ideas ?

Powderman
December 17, 2009, 05:29 AM
It is my understanding that FFFFg is priming powder. If that is available, you might try that.

If that is not available, you can "sift" your powder through fine cloth by putting a small quantity on the cloth, and gantly moving the cloth back and forth over a container. The "fines" can be used to prime.

Or, if I were to make a cannon such as this, I would probably acquire an actual firearm "lock", with a hammer, and modify my flashhole to securely hold a shotgun primer.

Doc Hoy
December 17, 2009, 06:43 AM
Might go to the manufacturer of the piece. Ask if they have had others reporting ignition problems. They might have a quick fix. At the very least I bet they would be interested in your experience given that you use your own powder.

darkgael
December 17, 2009, 07:13 AM
Have you tried a fuse? Store bought.
That 5/64" is probably too narrow for homemade fuse. The stuff that we make tends to produce more fouling than the store bought factory stuff.
Pete

robhof
December 17, 2009, 08:31 AM
darkgael has the solution. The commercial cannon fuse is pretty good stuff and a few ft last quite a while. I also have a 3/4" bore that my brother and I bought the barrel from DGW some 40+ years ago and made the carriage as a scout project. I put it away in an ammo box with fg Dupont powder and about 6 ft. of fuse. I found it a few years ago, going through my late parents house and poured a charge and lit the fuse, it still went bang, and the fuses even work wet. The fuse is still sold in the back of gun mags and I've even seen it on EBay.

Springfield Kid
December 17, 2009, 11:04 AM
Dixiegun works sells the fuse , 50ft lenghts I think it cost 7 bucks last time I bought any .

Pahoo
December 17, 2009, 01:19 PM
I have three home-made cannons and also use the bought fusing cord. My touch holes has to be about 1/8" diameter but whatever it is, there is a slight air gap around the fuse. I have never had a miss-fire with mine. I mostly use Pyrodex.



Be Safe !!!

sam0812
December 17, 2009, 02:38 PM
I think my fuse hole might be a bit small. I had this cannon made on a cnc lathe at work and was just guessing the hole diameter. if I can make a fuse small enough to leave a small air gap around it seems to work. I cant legally buy commercial fuse here in Australia:mad: I thought maybe a different powder composition may work.eg no sulphur in the mix. Anyhow thanks to everyone Its good to talk to people who understand.

grymster2007
December 17, 2009, 03:03 PM
Sam,
Can you post pix of your cannon? I've been thinking I'd make a cannon or two when I retire and would like to see what others have done.

I've seen some cannons that use percussion caps.

zxcvbob
December 17, 2009, 03:13 PM
How about just putting a pinch of FFF or FFFF powder on top of the flashhole in a little mound and touching it off? Low-tech approach. (might need to countersink it a little)

Springfield Kid
December 17, 2009, 04:12 PM
Not allowed to buy cannon fuse , seems like I have seen a device that uses caps to fire cannons and such .
Might have been at Dixie , but I don`t remember now .
Someone told me our fuse is traceable now with some kind of codeing in the fuse even after it burns .
I don`t know , whats the world comming to .
I guess pileing powder in the touch hole is better than nothing .
would be hard to run and light that powder at the same time though :confused:

Pahoo
December 17, 2009, 04:47 PM
A few years back, I had some small cannons that had a 3/16" bore and 1/4". I could not buy fusing so I bought some rolls of caps and rolled them up leangthwise for about 2". Made sure to have one cap in the hole and lit it off and it worked. Got burned a time or two.

Can you post pix of your cannon? I've been thinking I'd make a cannon or two when I retire and would like to see what others have done.

My favorite is a scale model of an Naval 8-pounder. Made out of SS with a 3/8" bore. I got the plans on the internet. Just google it. Last month there was a guy at the range that was shooting golf balls with his. Claimed you can't track them flying and I couldn't.


Be Safe !!!

MacGille
December 17, 2009, 04:59 PM
Sam, use a #1 center drill, it will make a funnel shape into the combustion chamber. I have used fuse, loose powder in mine with never a misfire.

darkgael
December 17, 2009, 05:08 PM
Here's a picture of a little golf ball mortar that I made based on a design submitted in a contest over at the BP cannon/mortar forum at Greybeard. It's called the KISS mortar ("keep it simple..."). Mortar design by DD.
Machining the bore was right at the limit of my little 4" lathe.
http://i492.photobucket.com/albums/rr287/PeteDoyle/KISSmortar2.jpg
Great fun.
Pete

sam0812
December 18, 2009, 12:51 AM
HI All .Thanks to you guys I can sort it out now.Heres a couple of pics. Its 15" overall with a 9/16 bore.I blued all the metalwork.I work as a sandblaster,laborer and general dogs body in a large metal fab works so I can get access to materials and cnc lathes etc:)

hickstick_10
December 18, 2009, 01:27 AM
Jam one of those birthday cake sparklers down the touchhole.

Those wires covered with that black stuff so when you light them they burn down, sparkling the whole way.

Cheap, works, and it even looks like something out of loony toons. You wont get ignition with the powder only method unless you get your touchhole packed full of powder (unlikely with a verticle touchhole unless you take the time to do it) If you go this route use a lintstock

darkgael
December 18, 2009, 07:05 AM
Sam: That is a nice looking little shooter.
Pete

grymster2007
December 18, 2009, 10:07 AM
Very nice sam! Clean little unit and thanks for posting the pix.

madcratebuilder
December 18, 2009, 10:27 AM
Damn fine job on that sam. You ever fire a projectile from it?

Pahoo
December 18, 2009, 11:54 AM
WOW .... :eek:
Very nice work, Sam. And this little beauty has "fun" written all over it !! See if you can send us a picture of the touch-hole.
hickstick_10: Jam one of those birthday cake sparklers down the touchhole.

That sounds like a good suggestion should work well. Heck, it might take a littel time to burn down but will keep burning till it does it's job.

Sam, be sure and let us know how you made out ... :)


Be Safe !!!

robhof
December 18, 2009, 09:04 PM
That's alot spiffier than my old cast iron cannon. I did experiment with percussion ignition awhile back using a nipple with the threads ground to fit into the touch hole(didn't want to tap the cannon and it not work) held it on with pipe clamp drilled to fit top of nipple through, fired it with hammer taped to end of broomstick, it worked when I made contact with the cap, went back to fuses, more reliable.

sam0812
December 20, 2009, 06:28 AM
Thanks again to everyone who replied to my original question. I thought my powder mix was somehow wrong,the main charge I know is very explosive but to use it as a fuse would instantly foul the touch hole. I now roll a tiny bit of 'dust powder' in a cigarette paper along with a 1/16 drill. Roll it as tight as I can,then slowly pull the drill bit out,twisting it as I go.I then cut off one end at a 45 degree angle and stick it in the touch hole. Its like a little rocket going off,straight into the hole.:D Its amazing how little powder you need in the fuse for it to still work.Next time I will drill 1/8" touch hole instead of 5/64" and see how that goes. THANKS AGAIN from Sam

darkgael
December 20, 2009, 07:09 AM
Sam: Have you tried making fuse from saltpeter and water and string? Or from saltpeter and sugar, water and string.
Last, the best homemade fuse tutorial that I could find involved common match heads turned into a slurry in a small amount of water and then mixed onto a piece of wool yarn. Kind of work intensive but it yields two feet of fuse and you probably only need two to three inches at a time.
Here's the video on youtube. The burn is the best that I have seen in home made fuse.
http://www.youtube.com/watch?v=NkKMHblUXI4&feature=related
Pete