34 replies to this topic

[Burtgummer]

Well, I'm back with some more questions!

Formy shells that I'm building, I have been using fast visco that burns at about 6 seconds per foot. However, I'd love to have instant ignition as I will be using electric firing. So, my only option is some form of quickmatch. I have made quickmatch using two strands of black match, but it did not burn really fast, maybe 1 second per foot. I have also made quickmatch using the masking tape method. That method burns much, much faster, and I would prefer to use it because of that fact and it is easy to make quickly. However, will the seal between the lift cup and the shell create too much of a pinch in the tape-quickmatch, preventing it from igniting the lift charge? I'd rather not test this and be left with an unfired shell, as I think we can all agree on. So, will that pinch area stop the quickmatch from launching the shell?

I was thinking of taking some visco and putting it between the lift cup and shell to open a gap, but I'd like any opinion on the matter first.

Thanks!

Edited by Burtgummer, 21 June 2008 - 03:33 AM.

[ExplosiveCoek]

You can better solve this problem by making a very small hole IN your liftcup, put your quickmatch trough this hole put some tape over it to make sure the lift doesn't leak and you're finished .

[Arthur Brown]

First perfect your quickmatch! When the BP is perfect, and the tube is perfect, QM burns as several hundred feet per second. Also if you use several strings then the interstices between the BM strings inside the paper tubes form perfect continuity.

Please test you QM til you are satisfied of it's perfection before you add shells or anything else that adds hazard.

There are numerous tutorials on how to make BM and QM on this site, there are also several tutorials indicated in member's home pages (see links in signatures).

[BrightStar]

So, will that pinch area stop the quickmatch from launching the shell?

Quite possibly - you would need to test it repeatedly to find out. I once had a potentially dangerous hang-fire with a home-made leader. It stopped burning where it was glued in to the lift cup and became pinched just 1 mm from the lift charge. I had to sit and watch it for the best part of an hour before it was safe to re-fuse.

To make good quickmatch leaders there are a few key points:

- Use your fastest ball milled willow meal
- Use your best quality black match - use the 'soak in BP soup then coat in thick BP putty' method
- Use three or more strands - commercial stuff has the equivalent of six
- Use kraft paper pipe for strength (I spiral roll it on 8mm dowel) waterproofed with a layer of parcel tape

Pinching good quickmatch just makes it burn faster!

Edited by BrightStar, 21 June 2008 - 12:02 PM.

[pyrotrev]

Another tip: Soak your string in KNO3 solution and dry before coating with BP slurry - stops the KNO3 leaching out of the slurry and reducing its burn rate, also means that if the BP coating comes off a short length, it will smoulder through and continue burning after a bit. As Brightstar said, use multiple thin bits of string, not only does it give faster flame propagation, it's more flexible and less likely to shed powder if bent. A few% of a binder helps keep the powder on the string too.

[portfire]

Theres some good advice from Arthur Brown, BrightStar Burtgummer

I'm now able to make flat, waterproof match-pipe, and with a few strands of good quality BM, burns very quick indeed. The key is having a well impregnated, hot burning BM. As said, they are some good tutorials on making quality BM, one can be found in my Z cake tutorial. Its a little time consuming at first, but once you've got the process down, you can make it fast enough.

With regards to the pipe It's self, waterproof It!!! I recently had a problem with damp QM, BM due the fact that I didn't waterproof the pipe and had some hang-fires.

Pinching will not affect good QM. The leader on my Bag-Mines is secured with a clove hitch knot when I close the bag, and I really pull the knot tight and never had a problem. The same go's for my drivers, fountains etc.

Here's a pic

[cooperman435]

as long as your blackmatch burns at all you wont get a hang fire as there's so much pressure and hot gasses trying to get in every direction from the sheathing that some has to go through to below the wide part of the shell. even if it didn't your blackmatch would still burn through the gap and re ignite quickly below it.

[Burtgummer]

Well, I would prefer not to use blackmatch at all. I've been making quickmatch by simply running the sticky side of masking tape through a pile of granulated black powder. I then fold it lengthwise, and use another piece of masking tape the same length to make a tube of granulated black powder. This is a very easy way to make short lengths of quickmatch, but I think if I pinch it (like a lift cup), it might not burn through. I do know that is one end isn't open, it will make a rather loud report.

[cooperman435]

thats not quickmatch then its sticky match!

Quick match has blackmatch running down a length of loosly fitting paper tube.

[Pretty green flames]

Well, I would prefer not to use blackmatch at all. I've been making quickmatch by simply running the sticky side of masking tape through a pile of granulated black powder. I then fold it lengthwise, and use another piece of masking tape the same length to make a tube of granulated black powder. This is a very easy way to make short lengths of quickmatch, but I think if I pinch it (like a lift cup), it might not burn through. I do know that is one end isn't open, it will make a rather loud report.

Please, do use regular quickmatch, i've seen one to many shells fail as a direct result of choking sticky match. This is not something you want to experience. Having a shell with a smouldering fuse inside a mortar is among the most dangerous things that can happen.

[concept]

Just a quick post on how commercial quick match is made, very interesting and it would be amazing if someone could build such a machine at home. - not my video by the way.

Cheers Doug

[ultrabuf]

Hmm thats very interesting that they put the BM through the paper tube while its still relatively wet.

[Arthur Brown]

An important maxim for all artificers! 100% fire when wanted, 100% on time. 100% no fire at all other times Failed fuses are dangerous - your left hand is NOT a spare!

[Burtgummer]

Alright, I know what sticky match is, or thought I did. I was under the impression that sticky match was so-called because it would stick to surfaces easily.

In fact, here is a video of a 2 foot length I made using this method.

I'll see if I can make some blackmatch that works alot better in a papre tube, as my previous tests with 2 strands were at the speed of fast visco, about 6s per foot.

[cooperman435]

You didnt know what it was then!

You were referring to sticky match but calling it Quickmatch and state in your second statement "or thought I did" so you didnt!

to make satisfactory quickmatch just make thin strands of blackmatch and make a 3 or 4 layered paper tube 1/4" ID to put it in.

Whilst some will say that many paper turns are unnecessary and I agree that 2 layers are enough it does makes it faster and especially so with poor blackmatch

Thicker paper wraps will be of comparitable speed to thin commercial quickmatch.