Slightly interesting difference in mid 70 Estes motor vs modern

[J Blatz]

Recently flew my trusty Jet Freak glider on some old Estes 1/2 A6-2 motors and noticed that the nozzle area has a distinct orangey residue. I am posting pics of the older motor vs a modern one.

Was Estes running iron oxide or something like that as a catalyst back then? I always assumed their motors were just standard issue KNO3/charcoal/sulfur but maybe I am mistaken about that.

 

[prfesser]

To the best of my knowledge Estes uses Meal D powder to press their motors, so yes it's just standard issue BP. Good reason for them to buy Goex. Possibly there was an additive to the delay way back when. (Reaching) There wasn't anything yellow on the pad that would have deposited on the motor, was there?

 

[Daddyisabar]

What I have heard from ye ole tyme pyros is the trade secret formulas could change depending on quality and and availability of magical ingredients. Modified whistle mix for propellant, modified smoke bomb for delay and the real BP stuff for ejection. Secret binders and varied POOPY CLAY mixes for nozzles and caps. Ancient Chinese Secrets? These guys were ancient, making local Denver fireworks back in the October Sky days. Pressing that magical powder! Hardened Cold Warriors with little to no fear of Sputnik.

Sometimes the bottom of my motors are covered in a mysterious redness after use. I ask the great pyro masters and they say something like "they put some oxide in that batch." They say not to worry my pretty little head and be sure to eat plenty of iron as part of a healthy diet. Oh the great BP mysteries and wonders, just please don't CATO or blow a nozzle or lack an ejection charge, leaving the clay plug at the top completely in tact.

I promise to be good and not to go on or eat up any more of those bad dates! Only use those dates in oddroc saucers or expendable birds! There are good reasons for trustworthy motor certification.

I sure hope they can continue to get quality powders at good prices from the supplier. Like the good ole days when the MIGHTY D's seemed to have more punch. Maybe that was just a child's perspective. Or maybe my rockets are just heavier as I get older.

 

[Art Upton]

Rockets got heavier now, as we where young the small rockets were huge and roared to us little ones.

I've never seen orange on my Estes motors that I recall, maybe due to the clay's age?

 

[Sooner Boomer]

I rather suspect this is sulfur that has condensed
on the nozzle. There are several allotropes of sulfur, yellow, orange, red.

 

[J Blatz]

To the best of my knowledge Estes uses Meal D powder to press their motors, so yes it's just standard issue BP. Good reason for them to buy Goex. Possibly there was an additive to the delay way back when. (Reaching) There wasn't anything yellow on the pad that would have deposited on the motor, was there?

Nothing on the pad.

 

[J Blatz]

I rather suspect this is sulfur that has condensed
on the nozzle. There are several allotropes of sulfur, yellow, orange, red.

This is probably the answer. Or maybe like Art said, could be something in the clay.

Both of those make more sense than my original iron oxide idea.

 

[lr64]

Does dextrin, or something like it, leave a color sometimes? I think dextrin is supposed to be the other ingredient in Estes fuel, but not very much of it.

 

[AeroTech]

It could be a reaction product of the antimony trisulfide in the delay (antimony orange?).
https://en.wikipedia.org/wiki/Antimony_trisulfide