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Member Since 13 Sep 2007
Offline Last Active May 27 2020 07:11 PM

Topics I've Started

accidental efficient way to produce conductive lampblack

03 May 2020 - 10:31 PM

conductive lampblack is very useful in the production of bridgeless igniters these can be mass produced from ribbon cable.

i had purchased a 4kw diesel chinese heater . These have a drip feed pump and glow plug combustion chamber a12v fan blows hot air out for use in vehicles    etc  I was far too mean to spend money on diesel fuel so i ran it on kerosene central heating oil . after 5 hours running it stopped and would not ignite fuel.

i unbolted the combustion chamber the chamber was totally filled with about a cup full of high quality conductive lampblack i emptied the chamber into a secure jar. on reassembly the heater works well -no damage .

commercial production of conductive lampblack was from kerosene many years ago , its main use in industry today is making conductive rubber

 bridgeless igniter composition uses cmc a water based binder carboxyl methyl cellulose is found in cake shops as an additive when icing cakes if it isnt available then wall paper paste is a suitable alternative the small quantities of anti fungal present do not affect its combustion

who is still alive? or active?

16 April 2020 - 12:12 PM

greetings from sunny leicestershire  just managed to recover my password and log in 

 is anyone still active??  i will go and drag out my old ball mill and press   is there anyone out there???? 

Munroe effect - practical demonstration

26 January 2018 - 12:45 AM

Ref - History of shaped charge effect the first 100 years author Donald Kennedy

status- unclassified  general distribution


Dr Munroes experiments in 1888 pressing letters into a gun cotten cube then exploding it in close proximity to a steel sheet resulting in the letters being clearly imprinted into the steel sheet was the start of research into shaped charges .


In order to demonstrate this in a school or public lecture the ideal explosive is a stoimetricmix of hydrogen and oxygen  this is easily acheived by electrolysis  of  dilute sodium carbonate solution  This works better than electrolysis of water as the sodium carbonate in solution results in an increased conduction and current flow at low safe voltages . The steel sheet is replaced by a flat layer of plasticine on a thermostatically controlled heated mat .As the temperature of the plasticine is increased it becomes softer so by varying the temperature of the plasticine we can change the amount of force nessecary to imprint upon the surface. A flattened leaf is placed on the surface. The surface is then covered with strong detergent solution or bubble mixture. The hydrogen/oxygen mix from the electrolysis unit output pipe end is pressed gently into the bubblemix so that the whole surface is covered with a layer of bubbles-our explosive. The explosive charge is fired by a lit taper . This results in a loud satisfying bang  that delights the audience .By careful "tweaking" of the plasticine density clear  explosive formed prints of the leaf or a coin can be stamped into the plasticine.

Plaster of paris or dental plaster can be used to take a mould of the prints to form a more permanent record of the results .


Hydrogen oxygen bubbles can be fired on your hand without damage this may have potential for stage special effects???