A Stout Fellow

Mr. Creosote is under construction. I bought a nose cone that will fit a BT-80 tube, and used a single section of BT-80 I've had for awhile. I was going to make it two sections tall, 36", and do a long inner tube like Thor's Candycane has to reduce the interior volume and ensure ejection.



But I lack BT-80 couplers. So this is basically a bigger version of Dudley, a BT-60 rocket who served honorably. He survived more launches than almost any other rocket I've built. He's a large part of why I like to build larger rockets but stick to low power motors. Well, that, and I don't have to worry about FAA restrictions with my little A through C powered fleet. Since most of my favorite launch sites are within five miles of an airport, this is a consideration. If I was to start launching Cheetahs on F engines, I'll have to start worrying about waivers and flight paths and crap like that.




So here we have Mr. Creosote. For the name, it was between that and Phat Bastard, which Em objected to on the grounds that I shouldn't say 'bastard' around my kids and I objected to on the grounds that you shouldn't spell 'fat' with a 'ph.'

I'm thinking of ways to make his paint job look tuxedoish.



I've been experimenting with techniques employed by mid and high powered rockets. Not that Mr. Creosote needs it, but it's good experience if I ever do decide to build a bird that does. Plus, it's fun.



First off, I've used white glue almost entirely for all my models to date. A bit of Super Glue gets in there, the occasional plastic cement, but mainly Elmer's Glue All.

This is my first foray into epoxy. I've never mixed epoxy before. I got the five minute kind, and I think next time I'll try the 60 minute. Five minute epoxy just doesn't give you any working time. I try to line up elements I'll need glued: fins for the booster stage of the Echostar, a fin for Mr. Creosote, a motor mount and centering rings. And the stuff still turns stiff way too fast.



Plus, the longer cure epoxy is stronger. Which is a laugh, since I'm glue balsa onto paper tubing, and any epoxy is about fifty times stronger than either of those items. And a C6-3 is barely going to get Mr. Creosote high enough for his parachute to open, let alone take off with such ferocity that it rips the fins clean off.



This actually happens in the world of high powered rocketry. A world I don't even tangentially participate in. It's not hard to exceed the speed of balsa when you start launching big boy stuff.

I also used sanding sealer on the fins this time. I have a jar left from an early rocket I built, which had instructions calling for it. It amounts to doping the wings, making them stronger without adding much weight. Since it's almost entirely unnecessary, I don't always use it, and that makes the jar last and last.

The other thing I'm trying out is epoxy putty fin fillets. These are supposed to increase stability and strength of the fin-body joint, but also reduce drag. I don't understand how they reduce drag, but that C shape joint is better than an L shaped joint aerodynamically speaking.



You just cut off a bit from a stick of the stuff, roll it around to mix it, then roll it into a snake. Then mold it into the fin joint like so.



The putty is tricky to work in because when you try to smooth it with your finger or a tong depressor, it wants to crack. I used some regular epoxy to smooth out my fillets when they were dry. They're still not as smooth as I'd like, but not bad for the first time?



One thing that is nice about it, I had Marty Graw pull off his launch lug one time, and I'm pretty sure Mr. Creosote's launch lug would stay on in the shock wave from a nuclear blast.



Now if I had some BT-70 tubing to go with that one nose cone...