Estes D engines

[Lancecrafter]

I launched a Storm Caster last month, flew great. I'm concerned about some minor wrinkling that happen near the engine mount and center rings, in the air frame. I showed this to local rocket master, he said it was from the heat the D12-5 engine puts off after the discharge and during flight.
I'm currently finishing a Sea Strike "D". Should I put an exhaust port in the air frame of the booster stage and in the main air frame, between the centering rings? Would this allow some of the heat to escape or just weaken the rocket prematurely?

[CPMcGraw]

I launched a Storm Caster last month, flew great. I'm concerned about some minor wrinkling that happen near the engine mount and center rings, in the air frame. I showed this to local rocket master, he said it was from the heat the D12-5 engine puts off after the discharge and during flight.
I'm currently finishing a Sea Strike "D". Should I put an exhaust port in the air frame of the booster stage and in the main air frame, between the centering rings? Would this allow some of the heat to escape or just weaken the rocket prematurely?

Presumably this was forward of the engine mount (upper ring), and not between the rings?

Is there any scorching near (around) the wrinkle? This could be an indicator of the wadding being packed too tightly, causing the deployment charge to become stalled long enough to scorch the inside of the tube at the point of the jam. The landing then could cause the wrinkle at the weakened location.

If there is no scorching at the wrinkle, could there have been a "thumbprint" at this location, where the tube may have been grasped a little too tightly? Not immediately visible, but showing itself after a fairly healthy launch and landing cycle?

As for the pressure vents in a booster, this comes right out of the Handbook. Stine recommended this practice, but aside from a variation used by Centuri (Pass-Port), no one really adopted the method. The chapter on staging makes the ignition-separation sequence very understandable, and if you have not had the chance to read it yet, go grab a copy and digest the info slowly.

A slip-fit sleeve of Nomex would help improve the usable life of that booster...

[Lancecrafter]

No scorching or thumb mark, the rocket was solid when it left the pad, it did land on concrete.
Just not sure how much heat builds up between the rings of the engine mount. Just trying to get a good launch with Sea Strike "D".
I read the a section in the NAR member guide book, about the pressure vents for extended length boosters up to 9" and understand this technique. Just was wondering about the amount of heat between the center rings and of the engine mount and how it might affect the airframe. Sounds like not much of a concern. Have you ever done a 9" long D engine booster useing the pressure vents?

[CPMcGraw]

No scorching or thumb mark, the rocket was solid when it left the pad, it did land on concrete.
Just not sure how much heat builds up between the rings of the engine mount. Just trying to get a good launch with Sea Strike "D".
I read the a section in the NAR member guide book, about the pressure vents for extended length boosters up to 9" and understand this technique. Just was wondering about the amount of heat between the center rings and of the engine mount and how it might affect the airframe. Sounds like not much of a concern. Have you ever done a 9" long D engine booster useing the pressure vents?

Crunching damage can come from stresses of landing and launching; landings are usually more likely suspects, however. The concrete may be 'the butler' for this incident...

I have not had the opportunity to fly a gap-space model yet, mostly due to not having a large-enough field to fly such a model. The Omega would be a good 'first candidate', since it has plenty of gap between the engines.

As for heat around the mount, it gets hot, but generally not enough to cause damage. The trapped air becomes something of an insulator between the rings, but if those very hot particles linger on the inside of the tube at one location, then they can quickly burn through the tube. You would probably notice the burn before any crunch, though...