Safe to ram?

[FlamingChicken]

Hello all.

I'ld like to do some testing with AP/AL/Red Gum + Alc/H2O as a rocket fuel. I did some testing as a green mix and I'm quite excited, although that doesn't take much. Anyway, I just wanted to run this by you guys because I would like to ram it.

 

thanks.

[jacob]

First off welcome to the fourm.

Second no, that's not safe to ram at all, it will probably explode if you try, you could try pressing it but you'd better be darn carefull (read blast shield) since it's basically a form of Red Gum bound flash, and normally rockets aren't pressed/ramed wet, just FYI.

Edited December 12, 2008 by jacob

[FlamingChicken]

Alrighty then, glad I asked. When I ram my rockets, I only dampen them enough so that it will hold shape if I squeeze it with my hand.

[jacob]

That's BP I assume? interesting, usually they are ramed completely dry, I think there's a method that uses Red Gum and Alcohol but I'm not familiar with it, if it ain't broke don't fix it I guess.

[Mumbles]

I've seen some discussion over at Passfire of ramming/pressing rockets slightly damp. I can't recall the guy's name right now. I want to say Ben Smith, but that doesn't seem right. Anyway, he was able to achieve higher densities and thrust via pressing damp.

[Swede]

If you're referring to ramming BP rockets damp, then yes I do it as well, using an acetone/MEK mix and enough RG to help bind a bit, much of it per Sleeter's "Amateur Rocket Motor Construction." The dampness keeps the dust down, the use of a solvent with such a high vapor pressure creates a motor which cures or "dries" very quickly, and the resultant fuel is dense and monolithic.

 

I've done it dry, too, with BP right out of the mill, and that first tap with the rammer often sends a puff of BP skyward from the air displacment effect. Annoying, messy, and I think prone to sparks and static. But it works, no doubt. I am not an experienced Rocket Man, but those are just my very limited observations.

[Mumbles]

Most granulate the rocket comp with water and no binder first. It crushes down easily with light pressure and completely negates the dust. Without the most precise tool from wolter or Steve himself, you'll likely be getting that puff everytime with fine powders. I've seen others take a whistle approach and granulate it with vaseline, or more frequently mineral oil.

[Aquarius]

I use the same approach as Swede, Red Gum as a binder and acetone as solvent. It's taken from David Sleeters book, wich is a "must-have" if your into making modelrocket motors or vand a higbly repeatable result.

I just ball mill the comp, moisten with water and rice the stuff. When dry, I add 6 to 8 percent acetone and press in a hydraulic press.

Gives a hard grain, with no messy airfloating BP.

Don't know if wetting & ricing is really needed, but it keeps the dust problems away.

 

Now, all I have to do is to get my hydraulic gauge attatched somewhere between the pison and the lever to read out the correct pressure beeing applied.

 

Any ideas, will a T-junction and a HP hose do the trick?

According to the specs in my powerpack, the max pressure applied by it is about 1500 PSI, and the working pressure is about 1100 PSI.

[Swede]

That is a great idea Xetap... Ilove using off the shelf stuff like that for Pyro. A precision bench press with gauge is high on my list once I get through with my perchlorate obsession.

[jacob]

Aquarius,

 

Can you get a picture of your press, a tee and gauge should be what you need but what does "HP" stand for?

[Aquarius]

I'll post a picture after the mod. And yes, "HP" means high pressure.

I went looking for the right hardware for the connection today, found some in the plumbing section, but I thing I'll rather got for a HP pipeline and fittings. Still waiting for my gauge(s) to arrive.

 

A bit OT, but an article on Passfire states the correct loading pressure for BP coreburners will be 6600 and endburners 8800 PSI.

Maybe a detail, but I gather the 6600 is equvialent to 8000 when the spindle is not accounted for?

[jacob]

Oh duh, and yeah DON'T use regular home plumping fittings for high pressure hydraulic stuff, it won't take the load.