PML Patriot - QT vs. Phenolic

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Dec 5, 2003
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I'm ordering a PML 1/4 scale Patriot for my L1 cert. I built a PML Tiny Pterodactyl several months ago and while it looked cool, I was unimpressed with the Quantum Tube airframe. Since then I've heard both good (easy to paint) and bad (tends to warp) things about the QT.

It looks like most PML kits have an option for Phenolic frames and I was considering getting that instead. I've heard that the stuff is brittle, but how brittle are we talking about? Is the tube that comes with that kit the Kraft Phenolic that PML sells or another product? I don't think that I'm up for glassing yet.
I so far have had no problems with the QT tubing, I did with the phenolic.
I have a scratch build using 4" PML phenolic.
The rocket tipped over from the breeze and the tube cracked!!
It didn't fall any distance it just tipped over.
If you order a PML kit it will either be QT or PML phenolic on request.
I've never built a PML rocket using the phenolic, but I built the PML 1/4 Patriot using the QT airframe and successfully launched it for my Level 1 with a Pro38 I285 back in the spring. :D For me, the convenience of not having to fill spirals on a rocket this large was all the reason I needed to go with the QT. I've also built the PML 2.1" Amraam, and I've never had a problem with the QT on either rocket. I did not glass the airframe on the Patriot, but I did glass the fin can. Aside from the QT / phenolic issue, let me know if you have any specific questons about the kit.
For that rocket I would stick with the Quantum tube. As others have said the PML Phenolic is quite strong but brittle, IMHO it really needs to be glassed. On their larger kits or ones where you want to push the envelope you can also special order the kit with PML's pre-glassed tube. That stuff is tough! I once had my PML Eclipse (preglassed version) dig a 7-8 inch core sample when the main failed to deploy, it came in fast and furious on a tangled 8 inch drogue and was heavy since it had a camera bay added. After I dug it out and chipped out the concrete-like plug of dirt out of the tube (the nose cone did pop off, but the chute stayed inside) I was surprised to learn it suffered no damage. Since then it has been through many more adventures and always comes back for more. My club members can testify its a work horse.
I'll cast another vote for picking the QT over phenolic. IMHO, you're planning to use this rocket for your L1, not break mach. Just K.I.S.S. ... The QT makes for a much easier build with this kit. Save the (experience of using) phenolic tubing for another project after you get your L1 ;)

You've probably heard/read it a million times before but make sure to 1) rough the QT wherever you're going to be applying epoxy, namely fillets, and 2) sand that piston till it slides freely inside the airframe.

(And yes, the phenolic tubing is exactly the same as the MMT tube that comes with all PML kits.)

BTW, you have made an excellent choice in the 1/4 scale Patriot to do your L1 on. Good luck & keep us informed of your progress!
Thanks for all of the input. I think I'm going to go with the 4" Patriot from Public Enemy.
I would do phenolic, because that is what I am used too. Never use quantum, but I am sure of one thing, paper stinks. It peels and comes apart and makes a mess and is an all around hassle.
I am with the rest...I love Quantum tube and have used it in many rockets from kits to scratch. You do have to get used to it's properties, but once the rocket is tuned in, the ejection system works like a dream as does prep and cleaning. No where else can you build a rocket (coat all wooden parts with a thin layer of epoxy) and after the launch, WASH it in a sink or with a hose...try that with paper...ewww the though of it! ;)

In all seriousness, you have to understand the properties of Quantum to appreciate what it will do for you...If you want to go ballistic all the time, the Quantum is not for you. The warping I have only hear of from one the desert, super hot temps...jeez, I would warp and melt there myself. In the midwest and east coast, you never hear of Quantum warping.

The pistons are a blessing if you beef them up and sand them to the right fit correctly. I fit mine in the coldest weather I fly in, around 20 degrees F, and they are good all they way up to temps in the 90's. The tube doesn't crack like Phenolic, is very flexible, finishes like a dream and will hold epoxy if properly prepared. It can also handle some weight without overstressing. It all comes down to what you want to work with and feel comfortable with building.

Now please note that I do use PHenolic in many other rockets, but those are usually glassed for strength and high stress. I like Quantum for durability, ease to use and cut, flexability and endurance, piston system optimised with the smooth bore, and ease of finishing. In general, it is strong enough to fly without the glass job you need to do on some phenolic birds. As long as you don't try to fly mach with it, the rocket will outlast the owner. I have seen the Patriot from PML fly and it is one sweet bird. I like it and the customer service much better than that from PE.