Estes Plastic Engine Retainers Charring

Has anyone found a way to keep the Estes plastic engine retainers from melting? After just a couple launches, the 29mm mount on my Ascender looks pretty rough.

I'm trying one coated with high temp (grill) paint at my next launch. But I have also considered trying to coat one in metal foil.

Pics?

I have a bunch of these in use. No melting issues experienced...

Mine look somewhat charred with the surface pretty rough, but they seem structurally sound after around a dozen flights (both BP and AP).

Keep them off the blast deflector by several inches if possible. Some minor toasting is going to occur anyways.

rharshberger said:

Keep them off the blast deflector by several inches if possible. Some minor toasting is going to occur anyways.

Click to expand...

I was thinking the same thing... Estes has been known to recommend how far off the blast deflector the rocket needs to be. For example the Mean Machine is 8" (In the newer release of the instructions, not the originals).

Charring is a better description. The retainers do appear to be structurally sound. I have updated the original post title from "Melting" to "Charring".

Thanks for the tip on separation from the blast plate.

Pics attached:
1 - From left to right: Charred 29mm stock retainer / 24mm stock retainer / 24mm retainer painted with Rustoleum 7778830 High Heat Enamel.
2 - Inside view of charred 29mm stock retainer. Charring appears to be from outside only. This retainer has done only 2 flights on Estes F15 BP motors.

I've flown TONS of flights with these retainers. As mentioned already, if you keep the rear of the motor two or three inches off the blast deflector plat you shouldn't have any issues with the charring.

John Boren

On flights with hobbyline nozzles that don't protrude through the retainer, I put a ring of ductape on the bottom and inner edge of the retainer.
Tape gets charred, peel it off, have a drink.

I've often wondered how much damage is done by deflector plates that are essentially horizontal and deflect the engine exhaust back up into the rocket. The launch pad I'm building will have a 45 degree SS deflector. I've been meaning to post and ask how everyone likes the Estes engine retainers, and how well do they hold up. This post answers that.

I generally use a 2.75" stand off(spent motor case), and get a bit of soot on my retainers. the angled deflector will tend to put a side load on the launch pad, as the motor thrust increases this can become significant.
Rex

Rex R said:

I generally use a 2.75" stand off(spent motor case), and get a bit of soot on my retainers. the angled deflector will tend to put a side load on the launch pad, as the motor thrust increases this can become significant.
Rex

Click to expand...

What about one that is shaped like an inverted "V" with the motor centered over it? I've been planning something like that for a while. My inspiration is from drawings I've seen in old books about using a large can (like a tomato juice can), cut open, and then folded, for a blast plate.

its' that whole 'Newton's 3rd law' thing going on if the exhaust from a motor producing 5 lb.s of thrust hits a deflector that is perpendicular to the exhaust, then the deflector will have 5 lbs of force acting on it(roughly), at 45 degrees that drops to roughly 3.5#. I've seen a slo-mo vid of a rocket launching from a porta-pad...the pad 'squatted' from the thrust load. also seen a vid where a hpr moved the pad sideways a foot or so. your /\ idea should work fine.
Rex