Neoprene contact cement as a binder for rockets. Reduce hygroscopicity, reduce CATOS, reduce pressing force.

[anapogeetoofar]

My first thread here, huzzah!

 

While reading the directions on the back of can of contact cement for no apparent reason other than I hadn't read them before, I thought it was rather interesting that the directions said to let the adhesive dry before hammering the two surfaces together. While pondering about how that worked, my mind wandered off to pyro land, something it does quite often nowadays, and I thought: "hmm, what if the sufaces being hammered together were particles of propellant? Would they be glued together as well?".

I decided to answer this question in the only way that seemed good at the time, mix up some propellant, stuff into a casing and see if it does something interesting.

So, I got some of my finest willow BP, last month vintage, measured out 100grams, and mixed in about 7 grams of neoprene (about 25-30 grams of contact cement) , an equal amount of ball milled KNO3 (to help ease the OB), and some acetone to make it easy to mix. After a few minutes of stirring, I spread it on a cookie sheet, and went to put it out in the sun. No sun, just rain, thanks Florida. So I put it in a warm place away from sparks.

 

After drying, I decided not to bother with the hydraulic press(lord knows how much trouble this kind of laziness has gotten me into), so I got out the 'ol jumbo c-clamp and a length of pipe (for leverage). I pressed a 1x1in slug, and found it to be almost rubber like, very dense, hard, but not brittle almost like an old eraser (anybody remember those damn things?).

I dropped it on the floor from the top of my head (I'm about 6'3") and it bounced once, then rolled under my bench, drat. After retrieval, I put the hapless slug through more tests, dropping it from 7, 8, and 10 feet, without damage aside from minor blemished on the edges.

I threw it at the wall, hard, and it got dented, and a few tiny cracks formed around the dimple. Then I tried drilling it, it drilled almost exactly the same way APCP does, neato.

I realized that I hadn't yet burned any of this comp yet, it could be fire retardant for all I knew, so I took it outside and found it burned only slightly slower than before, but with a different flame, if that makes any sense.

Encourage by this string of success, I made a 1lb end burner with the comp, still using the c-clamp and pipe, and huzzah! It worked! I didn't have a normal end burner to compare it with at the time, but It looked pretty darn close.

Then a core burner was made, which worked marvelously, and a nozzleless, which flew, but not nearly as well as normal BP, which is odd considering the performance of the end and core burners. Hmmm.

 

I also see that Mr. Nakka is doing some similar experiments.

 

So, to prevent boring you any more with my long winded descriptions, I'll just cut right to where I am now. I have three whistle comps, all Kperch, NaBenz,brown iron oxide, neoprene.

One is: 70/25/1/5

number two is: 70/25/1/10

number three is 70/30/1/10

 

One and three are hygroscopic, two doesn't seem to be. All will be pressed to 7000lbs, a bit lower than I usually go, but it should be okay, its research. I probably wont try the c-clamp, CATOS aren't my thing, but maybe I will.

Something tells me I'll have to use a slightly longer core than usual, but we shall see. I also have a funny feeling the whistle will suck, but I can always press the delay part with normal whistle.

[FrankRizzo]

I'm eagerly waiting for the result of your test.