51 replies to this topic

[icarus]

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???? 

[wayne]

Hi Steve,

 

Yes, there's plenty of us still out here...Not a great deal of experimentation recently apart from some crossettes.

 

Hope you're doing good!

 

Anyone else been up to much?

 

Cheers,

 

Wayne.

[BlackCat]

Hello Steve & Wayne. Greetings from a rather wet Northamptonshire!

 

I'm still around and occasionally looking at the forum to see if anything except tumbleweed appears. I'm still active but nor as much as I'd like, ain't that true for all of us? Most of my work has been with coloured flames, especially green at the moment and various gerb formulations.

 

Hoping to make an eprouvette this summer and a few other things.

[RichardH08]

Greetings all, from (a now sunny again) Bedfordshire.

 

I'm still pottering away at my long-standing investigation of the chemistry of some simple crackle compositions.

[samboradford]

i'm still around, although it feels like only just.  What are you up to Icarus?

[icarus]

Hi i am hoping to make a visco machine it would be very interesting to see how different compositions behaved as a fuse core I have been playing with fuse compounds mixed into silicon sealant and then loaded back into a sealant cartridge so the mastic gun becomes a fusing gun  if the compounds are reduced in viscosity by the addition of cellulose thinners then they can be dispensed from a syringe but cannot be stored in the syringe as the solvent damages the syringe plunger rubber 

[icarus]

there is still a massive space down the field waiting to become a private amateur research facility available for visitors to use  by invitation 

[icarus]

i made a pretty coloured flame lamp as a table centre piece the base had  an alcohol methylene cloride and boracic acid fuel in it .  A bubble lift powered by a fish tank air pump lifted the fuel up a pipe to the burner head where it could run down back into the reservoir. Whilst the air pump was on the lamp burnt vigorously, when the air pump was switched off the lamp extinguished out of fuel within a few seconds, I recorded it as my intellectual property/ design then didnt do anything with it   

[icarus]

propane flame projectors with a 5 metre fireball were entertaining when a petrol jet or coloured alcohol flame mix was fired through the fireball  

[BlackCat]

Sounds like you've been seriously busy Icarus!

 

Sam, you probably won't remember but you were kind enough to give me some advice on ammonium perchlorate based gerbs quite a while ago. I finally got around to taking a look at a couple of formulas based on the published "Blue steel Gerb" that I posted with my query and, in line with your advice, used a blend of amm perc and pot perc. I pressed the composition into a 21/2 x 1/2 inch tube using just 5g of composition. The choke was 50%, which is actually my standard and, undoubtedly helped by reducing the pressure in the casing. The surprising thing though is that that 5g charge burned for about 25 seconds, a long time for such a small quantity I think. The spray was only about 18 inches tall though but, not a bad place to be for further work in that direction.

 

Thought you might be interested given your earlier advice.

[samboradford]

That's great!  I'm glad to hear you had some success blackcat.  I had some fun with single based powder and strontium nitrate producing a nice roaring flame projector in a 2 inch mortar icarus.  I fully intended to perfect it too but the cost was a setback. I tried making my own base powder with nitrocellulose, camphor and glycol but just made a mess. 

 

I have a lot of bits and pieces I'm happy to off-load for free if anyone is in need of anything.

[icarus]

unusual formulation ??? where did you find the nitrocellulose and camphor formula ????

[icarus]

the only references to nitrocellulose and camphor i could find was in the production of celluloid. The challenge is to find a replacement that is relatively smokeless to replace the single base powder

[BlackCat]

On the subject of gerbs; the "Blue Steel Gerb" that I mentioned above is basically a blue flame with Ti sparks and the combination of blue a white sparks is particularly attractive. The fact that the gerb didn't self-destruct encouraged me to think of other combinations so I thought that a red with yellow sparks would also look pretty good so decided top have a go. the red was a KP:AP mix of oxidisers similar to my version of the "Blue Steel" and I used FeTi for the sparks. As it happened, yes I thought the effect was very attractive but what surprised me was that I also got a moderately loud crackling from the composition. The crackling noise wasn't as loud as dragon's eggs but it was louder than the crackle you can get with coarse MgAl. Now I've never heard mentio0n of a crackle effect with FeTi and there's nothing in any of my books even when FeTi is being discussed, mind you, I still consider myself to be a novice so wouldn't necessarily have come across such an effect.

 

I just wondered if anyone else had heard this effect.

 

Sam: if you have any redundant gerb tooling, especially 3/4 inch and 1/2 inch I'd be happy to take them off your hands.

[samboradford]

HI BlackCat, you'll find you can get coarse Titanium / FeTi to crackle in any BP based gerb. I have a video of one of my 1inch id titanium fountain somewhere I'll try to dig out.  I'm not sure what tooling I have in that size but I'll have a look.

 

Icarus, the camphor plasticizes the nitrocellulose, I also have dibutyl phthalate which I've tried amongst other things. Shooting powders are made by rolling the "toffee" then cutting it up into many fine flakes, of course, though that's automated.  Rolling / Extruding through a pasta machine might work, I lost patience and moved onto other things but I really should look at it again.