Author Topic: Brass Priming Quills (Read 1026 times)

Evil Dog · « **on:** March 11, 2005, 04:17:08 PM »

In the past I've fired my half scale Napoleon only via fuse... a 4" piece burning more or less 10 seconds. Good on a tightly controled range situation, but once the fuse is lit there is really no practical way to stop the firing sequence.

So, considered electric ignition using model rocket motor igniters... that lead to quite a discussion in a separate thread on this board. Problem is that my local hobby shop they are 5 bucks for a half dozen of them... that just adds to the expense of shooting although it does work very well for controlling exactly when the cannon is going to fire.

The next option is friction primers initiated via pulling a lanyard. One of the board members generously offered to send me a sample or two so that I could give them a try. Once again, a great way to control exactly when the cannon will fire, not sure at this point what they would cost though.

Than there is the percussion device used with musket caps... undoubtedly a great way to initiate firing but really not what I am looking for. Musket caps are relatively inexpensive though.

Decided I could just fill the fuse hole full of FFFFg and fire with a linstock. Then I remembered a device I saw some Civil War folk using probably 15 years ago. They would pour some FFFFg out on a piece of paper and pick it up with 1/2" wide scotch tape. A length of the FFFFg coated scotch tape would then be rolled lengthwise and inserted into a piece of brass tubing. After the foil wrapped powder charge had been punctured by a brass gimlet, the brass tubing was inserted into the fuse hole and fired via a linstock.

As Kelly Bundy once said on "Married With Children"....... Urethra.... I have found it !!!! That local hobby shop had a piece of 5/32" OD brass tubing 3 feet long for under 4 bucks.... enough for 14 pieces of tubing 2 1/2" long, the length required to reach the center of the bore. Used an awl to slightly flare one end of the tubing so that it would not go completely through the fuse hole. When held in a pair of pliers and set off, it sounds rather like a cap pistol. Will be a couple of weeks before I can get out to the range for actual live fire, but so far this seems as though it will be the way to go.

Double D · « **Reply #1 on:** March 11, 2005, 05:25:47 PM »

Don't do it's dangerous! The brass tube will become a high speed projectile when the gun goes off, going who knows where! They also can be sucked partial or fully into the bore from the vacuum created by the firing of the gun.

What you want is unwaxed paper straws filled with 4F. They can be hard to find but look around craft stores, that's where I found the last ones I used..

Measure the straws so that no more than 1 inch is sticking out of the vent when fully inserted. Fold and glue one end of the straw closed. Fill the straw full off powder. Fold the open end closed. To use, prick your charge, insert the straw in the vent and bend the part of the straw over that sticks out to break it. Light with Linstock.

Be aware the straw may not burn up. It may be blown unburned or smoldering out of the gun. The straw could also get sucked into the bore from the vacuum of firing, so check for it when you swab and worm.

Evil Dog · « **Reply #2 on:** March 11, 2005, 05:44:56 PM »

Hey Double D.... thanks for the warning, that was one of the things I was wondering about but didn't mention in the post. Hadn't gotten as far as live fire yet, guess that I would have found out the first shot. Will start looking around for unwaxed straws.... or may end up trying to make my own. I would still prefer to stay with a fairly small fuse hole rather than opening it up to 1/4" and beyond. Ever try to make your own straws?

GGaskill · « **Reply #3 on:** March 11, 2005, 05:51:23 PM »

My experience using 4F as priming powder, especially loose, is that it burns like fuse because there is no space between the grains for the flame to pass; consequently it only burns on the top. The idea with the scotch tape and the tube spreads the powder grains apart which allows the flame to pass quickly.

How about using straws and tape instead of the brass tube and tape?

Double D · « **Reply #4 on:** March 11, 2005, 05:53:16 PM »

Yep I did. Used them a couple times in my first mortar. They worked just fine. Couple times the burning straw went flying. It was just simpler to use green fuse.

Evil Dog · « **Reply #5 on:** March 11, 2005, 06:00:00 PM »

Hmm..... this could get to be fun. Coat the sticky side of the scotch tape with FFFFg and then roll it around a wire. Then roll and glue a paper tube around the outside of the scotch tape and remove the wire... the idea being to end up with a paper tube no larger than 5/32" OD. Something to experiment with over the weekend.

Evil Dog · « **Reply #6 on:** March 11, 2005, 06:58:50 PM »

Oh my.... just tried my first one. Coated scotch tape with FFFFg and then rolled it around a wood stick Q-tip. Then two wraps of a yellow sticky note-pad over the outside. Removed the Q-tip and cut the paper ends off so powder would be exposed. Touched the end of it with a hot linstock..... real good thing that I was holding it in a long pair of tweezers rather than in my fingers. In no way did it burn like a fuse.... a low grade firecracker would be a much better description. Should make for real quick ignition.

Cat Whisperer · « **Reply #7 on:** March 12, 2005, 01:57:11 AM »

I think I read that one of the purposes of the quill was to try to prevent erosion of the touch hole - but that it didn't work well.

It will be interesting to see how well the fragments are cleared (or not) when the cannon is fired.

Articifer Tom · « **Reply #8 on:** March 12, 2005, 07:07:24 AM »

Hey! Evil I sent samples of the quik match also ,it is in craft straw . I use to roll my own till found them they are about 17" long can cut into thirds. The box says Artstraws limited 1800 units 4mm this looks like life time supply to me. !/4 " cello tape , 4f , razor knife and good to go.

Double D · « **Reply #9 on:** March 12, 2005, 10:31:59 AM »

Hey, that's exactlly what they did burn like a fuse. It was just easier to use fuse. Maybe I will have try them again with tape, great idea!

Evil Dog · « **Reply #10 on:** March 12, 2005, 10:35:11 AM »

Hi Tom..... Yes, and thank you. According to UPS they are scheduled to arrive Tuesday. With a 4mm straw you must be running right close to a 1/4" diameter fuse hole. The main reason that I am rolling my own for the time being is to try keeping them as narrow as possible.... would like to keep my fuse hole 11/64" or smaller. Thanks again for the samples.

Articifer Tom · « **Reply #11 on:** March 12, 2005, 01:14:08 PM »

No, That should be small enought to fit in your vent is just over 1/8 th.

threepdr · « **Reply #12 on:** March 14, 2005, 08:01:09 AM »

I've experimented with brass priming tubes in my full scale threepounder. The tubes originally were designed to be stuck directly into the powder bag (thus eliminating the need for a vent pick) and then ignited by a portfire. The originals were usually sealed on the top with a cover of paper or parchment then waterproofed with shelac or varnish. It was almost impossible to set them off with slow match.

The ones I made had a head that was splayed open and had 4f powder stuck to the head so it could be ignited by the lintstock. All of the ones I fired went straight up in the air, just like a friction primer. They would fall harmlessly in the general vicinity of the gun.

Unless you plan to use the primer itself as a vent pick and set off by portfire, the need for a metal primer is really just not there. I use paper straw quils which have a piece of quilting tape rolled in 4 f in the tube and a head made of paper hole reinforcers with 4f powder stuck to it. THe round head allows a good surface for the lintstock to ingite the quile. I've never had a misfire.

Evil Dog · « **Reply #13 on:** March 14, 2005, 09:51:32 AM »

Hi threepdr.... yes, I've pretty much abandoned the idea of brass tubing. Have done some internet searching concerning paper straws and found that most commercial straws are now plastic (gee, big suprise there). I did find reference to both 4mm and 2.5mm paper straws though. To my way of thinking, the 2.5mm would be a much better choice as it would allow for a smaller diameter vent.

Experimenting over the weekend I have come up with what seems to be a quite viable alternative.... those 3" square Post-It notes. They already have a 1/2" wide adhesive strip on the back of them.... just pour some FFFFg out on a piece of paper and pick it up with the sticky side. Then cut the Post-It note about a half inch beyond where the sticky strip ends and smear the non-powder coated area with one of those glue sticks..... wrap around a wood Q-tip and it is done !!! Pull out the wood Q-tip and you have a 1/8" diameter paper quill 3" long. Have touched a few of them off with a match.... boy are they ever quick !!!! In actual use, I would expect to prick the powder charge, insert the paper quill and cut off any excess. THen with a small powder flask add about 3gr FFFFg on top just to make sure that it easily ignites with a linstock.

Speaking of linstock.... was down at the local hardware store the other day looking at 1/2" copper tubing fittings.... found a few that when put together should make a pretty serviceable head for a linstock... would use 3/8" cotton rope. Will post a picture or two of it when finished.

Articifer Tom · « **Reply #14 on:** March 14, 2005, 12:17:02 PM »

You won't need to cut any off . The straws work great on sub scale guns and mortars because it doesn't move you off target ,just pick and insert . The linstocks I've used we made of wood except for ferrule on bottom to stick in ground between shoots. The drawings show a 3/4 " hole near top but only 1/4" cord going through so a wedged plug will help pinch it ,you find you need to keep unwrapping the cord and advancing it in the hole as it burns about 2' /hr. or less.
The rules require you to have a defector on your mortar either set in place or hinged type to prevent it flying back . Care and trail /error come into play on making the slow match I once didn't rinse the saltpeter out of my cord . Went to a shoot lit my linstock had it burn up before the first relay ended in 30 min. looked like a slow fuse on a stick.

Evil Dog · « **Reply #15 on:** March 14, 2005, 02:59:42 PM »

Hey Tom.... Bought a 100' roll of 3/8" diameter twisted 3 strand cotton rope over at Harbor Freight a while back. Have been using that for my slowmatch just as it came off of the roll.... no rinsing, no nitrating or anything else. Seems to burn less than 2" an hour and so far has worked just fine. My current linstock is a simple 3/4" wood dowel with a 45 Long Colt case ran transversly through one end, the rim of the case then being cut off. My rope fits quite nicely through it, any excess just being wrapped around the wood pole. I like the idea of a spike on the other end for sticking it in the ground.... will have to do that on my next one.