Estes motors with ceramic nozzles?

[Grant_Edwards]

I happened to stumble into the Wikipedia page on Estes Industries and noticed in the "Estes Engine Construction" section it stated that the engine is built using a ceramic nozzle. I've never seen an Estes engine with a ceramic nozzle — AFAICT, they're compressed, unfired clay powder. So I edited the page changing "ceramic nozzle" to "clay nozzle".

Have there ever been Estes model rocket motors with ceramic nozzles?

[After the recent engine vs. motor thread, I've decide to randomly switch back and forth between the two.]

 

[prfesser]

I *think* the term "ceramic" was used to make it sound more technical. But my understanding is that they've always been clay.

And the "spotty" look of the nozzles makes me think that they use cat litter---looks like the scoopable stuff--- for this purpose. Certainly a lot of the pyrotech folks use cat litter.

Best -- Terry

 

[heada]

My opinion: Ceramic vs clay.... Estes doesn't fire the nozzle at high temp so it isn't converted into a ceramic so clay is the correct term. If they were to fire the nozzle at high temp and then glue it into the case, then it could be called a ceramic.

Kitty litter can be, but isn't always, bentonite clay.

 

[Grant_Edwards]

And the "spotty" look of the nozzles makes me think that they use cat litter---looks like the scoopable stuff--- for this purpose. Certainly a lot of the pyrotech folks use cat litter.

Now that you mentioned it, I had noticed that the clay used by Estes seems to have changed from a uniform gray to a lighter gray with colored flecks.

 

[5x7]

It’s not Hydroscopic so I doubt it is bentonite clay or cat litter. If there is a mineralogist here it would be interesting to find out what minerals are in it.

 

[heada]

It’s not Hydroscopic so I doubt it is bentonite clay or cat litter. If there is a mineralogist here it would be interesting to find out what minerals are in it.

What I've done in the past is to take bentonite clay, add parafin wax and melt it into the clay and then mix well. That then presses and works the same as clay without the wax but adds hydrophobic properties. Estes could be doing something similar.

 

[5x7]

I would be surprised if they did all that, if they could just press non or low bentonite clays.

 

[rharshberger]

I believe its bentonite clay and grog (crushed and ground pottery) and wax based on other discussions I have seen. The clay acts as a binder to the toughener (grog), and the wax reduces absorption of moisture so the nozzles are stable in different environments (dont shrink in dry desert environments and swell to much in humid environments).