Shell building question...

[braddsn]

Hey guys.. this may seem like a simple question, but being that I have not built a shell yet, I don't want to order the wrong thing. My question.... the paper tube that transfers fire from the time fuse to the center of the shell (I plan on filling my tube with strands of BM), what size tubes are you guys using? Are you making them or buying them? IF you are buying em, what size? And while I am at it... when you make QM, do most of you make your own "pipe" to wrap around the strands of BM? Or do you just get the kit? I just made about 200 FT of BM.. waiting for it to dry to try it out.

[schroedinger]

The easiest way is to just use some gummed tape for making the pipe or use some kraft paper and wood glue, roll the pipe and just put glue on the last two centimeters.

 

If you want to use buyed tubes, just get some thin walled 6.35 mm (1/4") tubes and use those.

[mkn]

+1 - roll up Kraft paper till you have a rigid tube ( for me .008 " paper about 4-5 layers ) Make it a little longer so it sticks out of the hemi, then cut it flush with the hemi edge/ equator

[gregh]

I used large drinking straws last year. I think they were from Sonic and were fairly stout. They fit perfectly over the time fuse. The plus side is, I had to get a milkshake every day or so!

[dagabu]

The tube is called a 'passfire' as it passes the fire from the time fuse to the center of the shell. They are normally filled with pieces of black match and nosed with a turn and a half of kraft glued to the tube and tied off (not too tightly) with a clove hitch.

 

The passfire tube is cut just shy of the half way point of the shell center (ball type) so that the fire erupts in the exact center of the shell. They can be rolled or purchased, the ID should be just slightly larger than the time fuse.

 

I prefer a stout walled tube, they are much less likely to be dislodged upon lift.

[Jordan]

Another way to get good fire transfer is to fill the passfire tube with 3-4 FA and cap with a layer of tissue paper secured on the sides with gummed tape. It fills the shell with flame before burst, igniting all (most) of the burst instantaneously. This gives a shell that extra woomph.

[dagabu]

Another way to get good fire transfer is to fill the passfire tube with 3-4 FA and cap with a layer of tissue paper secured on the sides with gummed tape. It fills the shell with flame before burst, igniting all (most) of the burst instantaneously. This gives a shell that extra woomph.

 

I did that with a series of 3" shells in 2008 since I didn't have any black match and all of the shells broke oddly. The passfire tube broke and lit the one half of the shell before the other in what was evidenced by a nearly intact half hemisphere and a banana'd passfire tube. That shell broke very low as the lift cup had a hole in it and was under lifted. The tube hit my in the thigh and it took me a long while to understand what it was.

 

Ask around but I am pretty sure that porting fire via black match is the most accepted way to pass fire.

[Dean411]

Imy favorite method these days is using the 1/4 id x 3/8 od tubes 2 and 4 inches long sold at pyro direct

the timefuse fits snug and I havent had any issues with them blowing out the side.

As Dag said I use BM on top of the time fuse to transfer fire to the shells center.

 

Dean

Edited September 25, 2014 by Dean411

[dagabu]

Imy favorite method these days is using the 1/4 id x 3/8 od tubes 2 and 4 inches long sold at pyro direct

the timefuse fits snug and I havent had any issues with them blowing out the side.

As Dag said I use BM on top of the time fuse to transfer fire to the shells center.

 

Dean

 

The spiral wound ones? That's what I use as well.

[Dean411]

Yes I wrap a 2 inch and a 4 inch together with gummed tape for my 12s as well I have had no issues since going this route

[Mumbles]

I use those as well for ball shells. I've also used 5 strand quickmatch instead of a hard tube with good success in single petal shells. The hard tubes really come into their own when making multi-petal shells. I use quickmatch as well for cylinder shells if I'm not using spolettes.

[dagabu]

I use those as well for ball shells. I've also used 5 strand quickmatch instead of a hard tube with good success in single petal shells. The hard tubes really come into their own when making multi-petal shells. I use quickmatch as well for cylinder shells if I'm not using spolettes.

 

Do you nose the spollette with black math to the core in your cylinder shells?

[Dean411]

I know you were asking Mum but I do only if its a salute cannister, if it contains stars I dont tie match on the inside

[Mumbles]

I fill all of my spolettes with blackmatch (3-4 pieces), and then nose them with paper, and finally pierce the paper. I usually use paper, but have half-assed it with masking tape when I was in rush. I meant to imply this, but probably should have just came out and said it. Nosed spolettes spit so much fire, I don't worry about anything else. They don't usually make it to the center of the shell, but cylinder shells break fine. I don't recall ever making ball shells with true spolettes, so I can't speak to that.

 

I only scratch the inside surface of the spolette. I've never done much with drilled back spolettes, but I suspect they would spit considerably more fire.

[nater]

Some say that drilling back a spolette ensures a positive transfer of fire. Mike Swisher had quoted a text, it may have been Rev. Lancaster, I cannot remember. I drill them back to ensure precise timing, but never thought about the flame being more intense. The black match and nosing spits plenty of fire. I have a week off work, so I'll make a video and see soon.

[schroedinger]

Well the drilling back really increases the ammount of fire going into the shell, it works similar to a rocket engine, but i don't think that it is needed as a spolette allready spits lots of fire. But it can be interesting on small shells as these can lose quite some power by such a big hole that a spolette creates. For those i can just recommend to use a bottle rocket tool, either use a Tube extender and fill up to the rim or fill as high as possible or cut the tube down to the powder after pressing.