Tubes and racks for Stars

[gilv58]

So I am planning in making/shooting several volleys of single 1" diameter stars out of mortar tubes on my next show.

 

I have some DR9 Tubes (1.2" ID). Is it ok to drill a hole for the fuse just above the plug to ignite the lift charge?

I take it I will have to wrap the stars to increase their diameter and make them fit in the DR9 tube? Or will I get enough pressure if I drop them unwrapped over the lift charge?

 

 

Gil V.

[giod]

So I am planning in making/shooting several volleys of single 1" diameter stars out of mortar tubes on my next show.

 

I have some DR9 Tubes (1.2" ID). Is it ok to drill a hole for the fuse just above the plug to ignite the lift charge?

I take it I will have to wrap the stars to increase their diameter and make them fit in the DR9 tube? Or will I get enough pressure if I drop them unwrapped over the lift charge?

 

 

Gil V.

 

You sure the ID isn't 1.8 inches? That's what it should be.. Overloading likely will cause your star to fragment. I would wrap it.

[Seymour]

Depending on your lift, no confinement may be needed. However at least for consistency, I definitely suggest confinement of some sort. While wrapping until the fit is tight will work, a card disk slightly wider than the tubes ID, jammed in on top of the comet is ideal. If fire risk is low and you are willing to be ghetto fabulous, a bunch of newspaper jammed on top makes a working (if often on fire afterwards) alternative.

[Carbon796]

I have those same tubes from pyro direct, that I also shoot 1" comets from. You shouldn't need to build up their diameter. I make my comets reload-able and top fused. I use 1.5" masking tape and tape the fuse along the side of the comet, with 2 complete turns around the comet. Both the fuse and tape should hang past the edge of the comet about 3/4" so you have a " cup " on one end. Place your lift charge in the cup, then fold the masking tape over in segments. Starting with the fuse being folded down into the lift charge first. Then I tear off a square of tape and tape the bottom, to make sure it doesn't unfold. I use 1.2 grams of FFg for lift on average for 1" comets, with this method. Edited September 17, 2013 by Carbon796

[gilv58]

Giod:

While I have not measured them they should be 1.2" ID. I bought them from Pyro Boom. Here is their description :

 

https://www.pyroboom.com/products.aspx?name=mortars

 

 

carbon:

So the fire from the match will not ignite the star as it passes beside it on it was down to the lift charge? You wrap the star first than place the fuse beside it right? Any pics?

Edited September 16, 2013 by gilv58

[Carbon796]

You can run the fuse either way. But the type of fuse and comp will dictate which way is best for you. I use the quick grey fuse or quickmatch. I run the fuse against the comet, and the tape over the top of it. If you only have visco and are using a fast burning comp. Tape the comet first, pierce the side of the " cup " with a razor blade, then insert the visco. Add your lift, fold, then use a longer piece of tape to secure the fold with and tape the fuse against the comet. This will also close the slit for the fuse so you don't lose any lift powder. You can also place a square of tape over the top of the comet. To help delay ignition of the comet from sparks, when using visco. If your using a hard to light or slow burning comp, and visco, I would just run the fuse against the comet, to aide ignition. I'll try posting pics tomarow if you want.

[Mumbles]

DR9 is a grade of pipe not a specific size. It's similar to schedule 40 or schedule 80 with PVC. The only time you ever really see DR9 or DR11 show up is with consumer mortars, so it's easy to not realize. Other than that, you just normally see HDPE being sold by nominal diameter.

[psyco_1322]

DR9 is really just short for SDR9. The SDR stands for Standard Dimension Ratio, and is the ratio of the pipes OD by it's wall thickness. It's mostly just done with polyethylene pipe, and helps to relate it's pressure ratings. All the PEX pipe we make at work is SDR9, and it ranges from 1/4" up to 2". SDR11 is another common size, but it's basically the same stuff, with a thinner walls. The OD and ID is controlled to make sure it will fit any pipe accessories we sell. The SDR rating is basically just for pressure references.

 

While PEX is made from HDPE, it's not really the exact same thing since it gets cross-linked. The pipe is still sold by it's nominal diameter, just like PVC and other pipe is.

[gilv58]

I'll try posting pics tomarow if you want.

 

carbon:

I would appriciate pics if you can.

 

Thank you in advance either way. You have been very helpful.

 

Gil V.