Random Thread #1

[optimus]

There's no need to bother with fancy bent wings - just use straight popsicle sticks and they work just fine.

 

Alan has a nice page on spinning things, including helicopters:

 

http://www.vk2zay.net/article.php/16

[mormanman]

I'm upset a little b/c I have to do the 5 hour OSHA Safety Course for metal shop and last year I did the same thing only 10 hours for wood shop. The 5 hour one is just short but the 10 hour one has the same thing up 5 hours. Its lame b/c I've already done it.

[tentacles]

mormanman: for the ball mill belt, I used an O-ring from a farm/surplus supply store, but a pool store should have giant ones as well. An alternative that is cheap, is to get a bicycle tube and a patch kit, glue together a length that's appropriate, and then if you want you could put glue on one side of the belt, and roll the edge so it's round.

[crazyboy25]

happy cause i got bioshock sad because my video card sucks so it is really jerky

[kingvitamin]

Well i'm just working full time and and getting my schoolin in full time and coaching wrestling part time. My happy semi drunken life has all but vanished.

[h0lx]

This forum really needs a favicon...

http://img213.imageshack.us/img213/7194/123456bx1.png

just dull without it..

[rocket]

I’d just like to say GO THE CATS!! Any Aussies will know what I’m on about.

[Tweetybird88]

I’d just like to say GO THE CATS!! Any Aussies will know what I’m on about.

I'd just like to say WTF ARE YOU DOING YOU WORTHLESS METS. LET'S BLOW A 7 GAME LEAD!! Any Americans will know what I'm on about.

[weknowpyro]

Does anyone else think this might work for producing hydrogen peroxide on a small scale?

Firstly, decompose barium carbonate by heating to form barium oxide and carbon dioxide.

BaCO3---------> BaO + CO2

 

Then, heat it more so it bonds with oxygen to form barium peroxide.

BaO + O2 ---------> BaO2

 

Then, to receive hydrogen peroxide add any acid. For example if you used sulphuric acid, then the barium atom will displaced for hydrogen. Then barium sulphate will form.

BaO2 + H2SO4 ---------------> H2O2 +BaSO4

 

Does this seem plausible? The main part I am unsure about is the 2nd section on heating; I have slight doubts that barium peroxide can just be produced by heating barium oxide in the presence of air.

[asilentbob]

As i understand it the:

 

BaO + O2 ---> BaO2

 

reaction doesn't take place unless strongly heated in a very high oxygen atmosphere... like in a tube furnace with O2 being passed through the tube... I have wondered about it myself... could be wrong.

 

You can get disposable oxygen cylinders at stores like home depot often... so it could be plausible... perhaps put the BaO in a crucible and heat it to red heat with a bunsen burner, then pass O2 from the cylinder into the crucible through a steel pipe or something...

 

*Remeber that BaO and related compounds are used for fluxes often... so you might have to use some more exotic crucible... maybe graphite or nickel... but you would have to be careful that none carried over because when you react it with the H2SO4 and make HOOH its decomposition would likely be very catalysed with any C or Ni... I don't know.

[crazyboy25]

i admit i know nothing of making H2O2 but be carfull if you plan on distilling because hydrogen peroxide fumes can detonate.

[DeAdFX]

As i understand it the:

 

BaO + O2 ---> BaO2

 

reaction doesn't take place unless strongly heated in a very high oxygen atmosphere... like in a tube furnace with O2 being passed through the tube... I have wondered about it myself... could be wrong.

 

You can get disposable oxygen cylinders at stores like home depot often... so it could be plausible... perhaps put the BaO in a crucible and heat it to red heat with a bunsen burner, then pass O2 from the cylinder into the crucible through a steel pipe or something...

 

*Remeber that BaO and related compounds are used for fluxes often... so you might have to use some more exotic crucible... maybe graphite or nickel... but you would have to be careful that none carried over because when you react it with the H2SO4 and make HOOH its decomposition would likely be very catalysed with any C or Ni... I don't know.

I think renting a giant O2 tank from a welding store might be a better idea. The oxygen is under an even great pressure

The tanks have pressure gauges

The hose connection only works for the MAPPS/O2 setup and most likely nothing else....

[asilentbob]

Well... yeah... but just how much would one want to make?

[FrankRizzo]

If you're interested in hydrogen peroxide preparations, check-out this thread:

 

http://www.sciencemadness.org/talk/viewthread.php?tid=1325

[flying fish]

That reminds me...One of my college buddies was talking about Building an H202 rocket for the purpose of "trying to reach outer space." He did mention how concentrating the H202 would be "extremely dangerous", and now I understand why. I asked how he was going to prove it reached outer space, and he said he would have an altimeter with a radio transmitter of some kind on it. That smart ass seems to have an answer for everything...

 

On a different note, I've decided to start wearing gloves...and possibly a space suit when working with lampblack. Ok, the stuff was fine when I only required ~15% in the composition. But when you have 50% this stuff is horrible! I sure hope the results are good or I'm going to be pissed.

[weknowpyro]

Thanks for the help. I was afraid that pure oxygen would have to be passed through the Barium oxide.

Maybe something better for producing small amounts of barium peroxide. Would be to do electrolysis on water, collecting the pure oxygen gas inside a test tube. Then quickly adding the barium oxide into the test tube of oxygen.

Seems more plausible to me now, then just heating BaO in air.

[jacob]

Anyone have a engine radiator and fan for a 1993 ford escort lx wagon that i could have for cheap/free.

[flying fish]

Anyone know how to produce this lampblack effect?

 

The guy said they were "tigertail" so naturally I assumed the 44/44/6/6 formula, except substituting lampblack for the charcoal. Now I'm not so sure that I should have assumed that

 

So that's the mixture I used. I coin milled it for a couple hours and then rolled with excess water.

 

After they dried, I tested some to find only a typical orange fire dust spray, and not the exotic short tailed streamer effect that the guy in the youtube video achieved. Any ideas on what I might be doing wrong?

 

The only thing I can think of is making pumped stars instead...but I didn't think it could make that much difference.

[Mumbles]

I think it may have something to do with the wind. Normally lampblack hangs for a long time. Possibly the hanging tail was blown away. I'd try replacing less of it with lampblack, maybe 10 parts of the charcoal with lampblack. I do find it a little odd you want a shorter tailed effect. Generally people desire the long hang time formulas. For a shorter tail, try a hotter charcoal. Maybe maple or willow instead of whatever you normally use. I found that using willow in my spider stars made them very fast and bushy, but commercial airfloat came a reasonable tail.

 

To shorten the tail, you may want to replace charcoal with potassium nitrate. Maybe 54 KNO3/34C.

[flying fish]

Thanks! I usually do like a longer, hanging tail, but I was for some reason liking the effect seen in that youtube video.

 

I guess the main thing that was bugging me was how course the sparks were in my attempt. The sparks that I get are large and very dispersed. I was hoping for more or less the opposite, so that the pattern is more visible. That way it doesn't just look like a random collection of orange sparks.

[tentacles]

Here's some randomness, I recently got a hotplate/stirrer, any tips on using it? Should I put something between the plate (seems to be aluminum) and the glassware?

[asilentbob]

Aluminum oxide is pretty resistant and takes heat well... you should be fine so long as you don't spill stuff on it all the time... I recently got a hotplate/magstirrer too off ebay used... thermolyne something... kinda beatup... but good looks don't affect chemical reactions here... only with women...

 

Pumped about 25 3/4" win20 crossetts a bit back... took me a while to get it down... the first ones were absolute crap... but i have had them drying under PC fan for like 18 hours or so now and im thinking im going to try some different burst compositions in them soon. What im considering now is to test the CuO/Al i have with ceramic grade CuO and -325mesh coated flake Al in 2 or 3 different ammounts as burst, granulated whistle in 2 or 3 ammounts, and granulated whistle cut with 5-10% charcoal in 2 or 3 ammounts... I like to avoid flash. I'm about to mix up the whistle mixes and granulate them through window screen in a minute. Might try some other composition for burst too... im looking through the PFP database. AVOIDING most flash comps.

 

I might have to wait for testing some of them untill i make enough end disks and find a suitable 7/8" or so tube to test fire them from.

[Mumbles]

Might I suggest trying oxychloride catalyzed whistle. I hear it works well. NC bound whistle is also supposed to be pretty good.

 

Are you using any sort of passfire fuse, or allowing for it to simply do it iself? Theres a formula in BAFN 5 about imitation thermalite by Petro.

[asilentbob]

No oxychloride... or i would...

 

I'm going to try it first without any fuse/passfire.

 

I'm thinking that at the least the end disk will get popped off... gotta get around to making those...

[tentacles]

asilentbob: The aluminum is pretty ugly, I'll probably anodize it before too long just for the hell of it. So it's safe to just place the beakers on the hotplate, no trivet or screen mesh or anything between? Obviously, don't crank the heat to the max on a cold beaker, etc. But otherwise?