I would contact AeroTech to make sure.
Not only do you have to be concerned with the material, but O-rings have a durometer rating associated with them that is often tied to the material they are made from. So it could be that they are engineered to perform with a material with a specified hardness.
If I were to guess though, it would be silicone since it typically has a higher tolerance for heat applications.
Greg
Hi all,
I am ordering some extra O-rings for some AT motors. Does anyone know if they are Buna or silicone? Thanks.
On this subject - perhaps someone who's knowledgeable about such things can weigh in:
On my recent L2 cert flight, I used a Loki 54/2800 stuffed with a K350 Moonburner reload. As per Loki standards, I used a silicone (orange) o-ring for the nozzle. The burn and flight all went great with no problems (and a successful L2!), however on cleanup I found something a bit odd. That silicone o-ring was sort-of melted a bit. It was still round, and still seemed to seal just fine, but it disintegrated upon removal and there was quite a lot of orange/white residue left in the slot that had to be scraped out. I've never seen this before other post-flight O-rings, and it was a bit disconcerting.
Now, Scott at Loki does state that petroleum based lubricants should not be used, and he lists proper lubricants that he recommends. I've always used white lithium grease in my reloads, but that was not on Scott's approved list. I did contact him via email asking if lithium was acceptable (before the flight), and he said it should be just fine. So I did lubricate with white lithium. This may be a factor?
Again, the burn and flight were just fine. But this is the first time I've seen an o-ring come out like this.
s6
s6,
It's not to unusual for the nozzle o-ring to do that, especially with a moon burner, because of the long burn time the nozzle gets really hot and stays hot till long after the motor has shut down. Most of the time they are still hot when you retrieve the rocket and start breaking down the motor. I have seen some o-rings turn to dust after a burn. But the motor burn is so short, and the graphite conducts the heat slow enough, that it is not an issue during the burn. Regardless of the material the ring is made of.
BTW. I have found that silicone rings are of no benefit in our application, they don't hurt, but they don't do anything that a buna wont do.
BTW. I have found that silicone rings are of no benefit in our application, they don't hurt, but they don't do anything that a buna wont do.
Stealth6 said:That silicone o-ring was sort-of melted a bit. It was still round, and still seemed to seal just fine, but it disintegrated upon removal and there was quite a lot of orange/white residue left in the slot that had to be scraped out. I've never seen this before other post-flight O-rings, and it was a bit disconcerting.
On my recent L2 cert flight, I used a Loki 54/2800 stuffed with a K350 Moonburner reload. As per Loki standards, I used a silicone (orange) o-ring for the nozzle. The burn and flight all went great with no problems (and a successful L2!)s6
Hey s6,
I just purchased the same 54/2800 hardware from Scott, which coincidently arrived today, and it is intended for my L2 next summer. The K350 has that nice long burn, what rocket did you use and what was you AGL?
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