Freese

What is the best stuff to use for a nice long (and long lasting) tail effect on a BP rocket? Al, Ti, FeTi, charcoal, lampblack? What about mesh size? I think a nice tail is as important as a nice header (maybe more so), but I"m way too cheap to buy all the potential material in all the different mesh sizes to experiment with them (and then be left with a bunch that is less then superior), so I thought I'd throw the question out for discussion.

What do you use for tail effect, and why?

I read somewhere (at least, I think I did) that one can use whistle comp in stinger (spin stabilized) rockets. I did one up using Potassium Perclorate and Sodium Benzoate (70/30) whistle formula. 1lb. rocket (3/4"i.d. x 3.5" long). Used Greg's excellent one pound tooling.

Did I just make a whopping big firecracker or do I have a potentially high-powered Stinger rocket?

Has anyone done this (sucsessfully)?

What about other propellents for stinger rockets? KNO3 + suger? KNO3 + sorbital? APCP?

I always figured that the side vent would prevent any possible for CATO, but proved myself wrong the other day (I think the grain cracked). Went BOOM, not UP!

Yeah!!! I am now the proud owner of a real ball mill. The used Thumler tumbler was a waste of money, but at least I can use the 9 pound (yeah, right) container for small batches (you live, you learn).

Armed with my new retort (which has an amazing resemblance to a butter cookie tin), I have blacked some white pine 1x4s (trees are noticable by their absence where I live). Using the 75/15/10 formula, I have made some nice meal, which burn almost as fast as Goex FF (not quite, but close.)

For rocket propellant, does it make any sense to press and/or corn the meal? Since it will be press/rammed into the tube, seems like wasted motion, but who knows (I'm hoping you do and will tell me.)

Should I add some Dextrin? Or will pressing the meal alone hold for a motor grain?

Is there a "good" way to clean the powder that sticks to the media. Rubbing each piece over mesh is way slow and inefficient.

For lift/break, how much difference does it make to press before corning? I still have some Goex left, but that stuff is unobtainium.

Thanks for your input. Now I just need the tooling to arrive (I have stinger tooling, just ordered bp core tool)

Be safe.

I just saw a picture of a rocket, looks like a 1lb. BP rocket, with a smoke tube taped along side and fused for simultaneous ignition.

Now the smoke won't provide any additional lift, just the added effect. Now I'm wondering - what if I taped a whistle motor tube to a BP rocket. The idea being you get the tail of the BP motor and the whistle from, well, the whistle motor.

Since both motors will provide simultaneous thrust, do you think the rocket will travel true (assuming that one uses the correct size stick for stabilization)? Or will the thrust from one motor cause an imbalance, perhaps because one motor give more thrust than the other.

Just an idea from a warped mind. I suppose one could just use a very small whistle, but what fun would that be...

Any ideas?

Fred

Last night I attempted to do up a batch of zinc spreader stars, using Weingart's Granite Star formula:

KNO3 14
S 2.5
Char 7 (150 mesh)
Zinc 40
Dext 1

I planned on doubling the recipe but for some reason (like, say, I'm a moron) I doubled everything but the zinc dust (only put in 40g). Also, I don't have 150 mesh charcoal, so I used 7 grams of airfloat. Since I have been interested in seeing what lampblack does, I substituted lampblack for the other 7 grams of charcoal. Both provide carbon and make a tail effect, right?

The recipe calls for wetting with 25% alcohol. I used isopropyl alcohol, (about 35% (maybe a bit more but less than 50%), which is what I had in the spray bottle). I had to use isopropyl as the only ethanol I had in the house was 12 year old single malt scotch. (and NO, I wasn't drinking it or anything else!) I used as little as possible. Mixed the comp in a plastic Rubbermaid container. Ran the comp through a sieve three times before wetting.

As I was incorporating the alcohol into the comp, the bowl began to feel warm (now that's odd...). I put the bowl down and waited a few seconds and rechecked, the bowl was definately feeling warm, like a hot bath. This, I thought, cannot be good so I grabbed the fire extinguisher, threw half a cup of baking soda into the comp, went outside and dumped it on a patch of bare dirt then dumped a couple gallons of water on it. No further reaction took place.

So, what happened??? Did I hallucinate this? Should I have taken a wait and see approach? I never had that happen before. Is there something in the lampblack that could cause this? I have heard that KNO3 and Al powder can cause a reaction, but there was no Al in the comp and no ammonium perc either. I have made spreader stars before using a similar formula and had no problems. I really like spreader stars and would like to start making them again, but I'd rather not repeat last night, had a bit of a panic.

And can lampblack be used as a general substitute for charcoal?

Can someone tell me what happened.

Thanks.