PML QT vs Fiberglass

So just wondering if there were thoughts on the PML QT vs a thin walled fiberglass when comparing costs and durability.

I have no experience with, say, MadCow thin walled fiberglass, but I did certify L1 back in 2000 (H-123W) with a PML Small Endeavor that was lost after launch 9 or 10 in some farm land....then found the following season (a year later) when a farm-hand ran over it with a tractor, returned it, and it has since been sitting in my storage for when I returned to HPR.

Needless to say, it flew again 16 years later, straight as an arrow, and returned intact. All that was needed was some sanding and repainting.

Any thoughts? PML is expensive but so is fiberglass; but which is better considering costs and durability?

Thanks
Nathan

I built many Quantum Tube rockets. For casual rockets that don’t attempt to fly extremely fast flights, Quantum Tube can be great. I’ve buried them in hard ground and pulled them out and reflown them. But I’ve also had a QT body tube crack for no obvious reason, landing in sagebrush under chute on a warm day. That shook my confidence in QT.
Once I made the change to G10/G12, I never felt like going back. It’s much more durable, handles heat and cold easily, and is much stronger. It’s also quite a bit more expensive.
Each has its place.

It's worth noting that thin-wall fiberglass is not as strong as the normal-thickness type. And in my experience filament-wound (G12) tubes are not as strong as the old G10 tubes which AFAIK nobody makes any more.

Practically anything will break if it hits something hard the right way.

Normzilla said:

So just wondering if there were thoughts on the PML QT vs a thin walled fiberglass when comparing costs and durability.[...] Any thoughts? PML is expensive but so is fiberglass; but which is better considering costs and durability?

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I've flown, burned, and rebuilt PML QT tube rockets many a time. I've spent more time painting and re-painting them thea building or flying.
I love building and flying rockets, not such a big fan of painting/sanding/prepping/painting/sanding/repainting.

So I switched to colored fiberglass (shout out to Rocketry Warehouse / MadCow) airframes.
Fiberglass is a little heavier per inch/sq, but more durable and way easier to maintain.
My pre-colored RW/MC airframes get a coat of clear, and that's it.
And even clear coast is primarily for protection during transportation, and to add a touch of shine to the bodies. I'm yet to retouch any of them after multiple flights and 30 fps landings. Not once. Look as good as new.

Wish I could say that about my cardboard/QT rockets.
Something always get nicked and scratched on those. Usually the nose cone and fins get it first.

But if you want to go higher for fun, or for altitude records, fiberglass is too heavy.
If funding is no object, there is also CF to explore - the best of both worlds.

Steve Shannon said:

Once I made the change to G10/G12, I never felt like going back. It’s much more durable, handles heat and cold easily, and is much stronger. It’s also quite a bit more expensive. Each has its place.

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+1.
I do find fiberglass airframes about +25-50% more expensive than similar QT bodies.
I can't say that they are more expensive to produce, only that the market seams to bear premium pricing for fiberglass rocket kits.

I do vote for fiber + touch of color!


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Quantum tube tends to crack easier than thinwall FG too. Of course, if you fly at a place like Holtville and come in hot on concrete, it don't matter what it's made of...

Fiberglass, hands down. QT is plastic, and seems like a relic of the past. I also had a PML QT airframe crack for no reason - twice. QT can't handle Mach, and there is the thermal contraction issue, as well.

I have a QT tube PML Callisto I started flying in 2003. I flew it once in 26ºF weather and the tube broke on landing. A piece of coupler and some JBWeld and everything is good. That was 4 or 5 years ago. Most flights today are 2000 - 3000 ft on H128W or H180W motors with a JLCR. It's still going strong and one of my go-to rockets!