Until now, for my endplugs and nozzles of my rockets and fountains I have been using rammed cat litter which has worked well. However I want to start adding Iron and aluminum to my fountain/rocket mixture to get the spark effect however I have heard that ramming compositions with metal powders can result in friction and sparks that could lead to the device going off. Is there any way to stop this from happening while ramming? what alternitives are there? I know I could press my composition, but how would I achieve adding the end plugs to both ends? or is there a better substiture then cat litter?
Thanks.
End plugs
Started by barr, Apr 10 2005 05:06 PM
3 replies to this topic
#2
alany
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Posted 10 April 2005 - 05:25 PM
Well you could ram the nozzle before you put in any composition. Pressing the final plug will work just as well as ramming it. You can press the entire device if you like. Cat litter itself is not any more likely than other materials to be responsible for an ignition during raming.
It is safer to press metal containing compositions, but most can be rammed with care, especially Aluminium containing ones. Then again big cast iron drivers and gerbs have been rammed for generations with relatively few accidents.
It is safer to press metal containing compositions, but most can be rammed with care, especially Aluminium containing ones. Then again big cast iron drivers and gerbs have been rammed for generations with relatively few accidents.
Alan Yates
http://www.vk2zay.net/
http://www.vk2zay.net/
#3
barr
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Posted 10 April 2005 - 05:31 PM
What about Iron containing compositions? are they especially sensitive to ramming? I may have over estimated the risk here.
When pressing the composition I was planning to construct a stand that would allow me to put weights on my dowl, "pressing" it. What sort of weight would give the equiverlent compression as ramming?
what do most people use as their endplugs/nozzles?
Thanks
When pressing the composition I was planning to construct a stand that would allow me to put weights on my dowl, "pressing" it. What sort of weight would give the equiverlent compression as ramming?
what do most people use as their endplugs/nozzles?
Thanks
#4
alany
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Posted 10 April 2005 - 05:49 PM
Iron is more likely to spark rubbing against itself in the composition.
Better to use a hydraulic press, more compact and faster to use. However you can easily compute the pressure exerted on the surface area of the drift face. Pressure is force on area, so for example if you put 10 kg of mass on a 19 mm drift it would press the composition to about 346 kPa.
The recommended pressing force for a core-burner is ment to be about 45 MPa (end-burners about 60 MPa). To achieve those kinds of pressures you need 1.3 and 1.7 tonnes respectively. That's a lot of mass, unless you plan to use a car as they weight.
I use wax treated cat litter and it seems to work just fine.
Better to use a hydraulic press, more compact and faster to use. However you can easily compute the pressure exerted on the surface area of the drift face. Pressure is force on area, so for example if you put 10 kg of mass on a 19 mm drift it would press the composition to about 346 kPa.
The recommended pressing force for a core-burner is ment to be about 45 MPa (end-burners about 60 MPa). To achieve those kinds of pressures you need 1.3 and 1.7 tonnes respectively. That's a lot of mass, unless you plan to use a car as they weight.
I use wax treated cat litter and it seems to work just fine.
Alan Yates
http://www.vk2zay.net/
http://www.vk2zay.net/
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