First try with salicylate fuel

[Maserface]

 

With all due respect, I believe that every one of the persons that fly whistle rockets I have spoken with in manufacturing at PGI, on Passrire and even Nski all agree that all variables being the same, Sali has a lot more power than Benzo.

Those "variables" are what make them different. As nater said, benzoates will fly on longer spindles than salicylate will.

 

Well unless you wax your tube, but that's another topic.

 

Point is, it's not apples to apples, I'd like to see (someday I will do it) how much thrust each propellant produces in the same size tube, with optimal core lengths for each.

[dagabu]

That's already been done, perhaps we can get Pete to share some of the curves he has received from others testing their whistle fuels? This is "Raw Power", not available power, all variables the same, the same, sali has more raw power and burns faster.

[Mumbles]

No, I agree. Every person whom I respect in the rocketry community states that Salicylate is more powerful. I've just always found it odd that Danny's tests tend to disagree with commonly accepted knowledge. I'd love to see some of the tests from the ACME stand, or as you stated the tests of the respective fuels each in their optimum configuration. In an ideal world, not that I'd want to be putting more work on people, but a three-fold comparison of Sodium Benzoate, Sodium Salicylate, and Potassium Benzoate would be fantastic. My very limited experience with whistle rockets has been than potassium benzoate is better than sodium benzoate, but that may be just due to it being easier to process and not being as hygroscopic/sticky.

[Maserface]

I plan on doing just that! Additionally I'll be testing potassium hydrogen phtlalate.

 

And for fun, I'll be testing as many Indy fuels as I can, eg MNO2, warp fuel, ap/benzoate.

 

This all of course, will be happening soon

[dagabu]

No, I agree. Every person whom I respect in the rocketry community states that Salicylate is more powerful. I've just always found it odd that Danny's tests tend to disagree with commonly accepted knowledge. I'd love to see some of the tests from the ACME stand, or as you stated the tests of the respective fuels each in their optimum configuration. In an ideal world, not that I'd want to be putting more work on people, but a three-fold comparison of Sodium Benzoate, Sodium Salicylate, and Potassium Benzoate would be fantastic. My very limited experience with whistle rockets has been than potassium benzoate is better than sodium benzoate, but that may be just due to it being easier to process and not being as hygroscopic/sticky.

 

I wish I was able to that Mum, I was all set to press a whole boatload of rockets to test at last years PGI. I have access to a full 50# bag of potassium benzoate and several pounds of Red Iron Oxide that I can donate if someone wants to donate the pot perc and tubes, I think we will have a party!

[Peret]

Curious what you mean by "brown iron oxide". Is that just hydrated red iron oxide? AFAIK, all the other oxides of iron are black.

[nater]

I could add some of that to my testing. I have K Benz, Na Benz and Na Sali on hand. Right now the earliest I can see burning whistle motors would be mid September at MFF.

 

As I have posted in another thread, work sometimes leaves me mentally drained to where I cannot fully concentrate to be safe with pyro experiments. So I wait until I have a few days off and good weather.

[mabuse00]

I think that in fact the kind of talk used makes it more confusing than it really is.

"More powerful" - as it depends on more factors than just the fuel I would not say this.

Fact is that salicylate burns faster and is thus more powerful when tested on the same spindle.

 

 

 

 

The brown iron oxide I used is supposed to be a mixture of Fe₂O₃, Fe₂O₄ and FeOOH.

Richard Nakka has some nice catalyst comparisons on his homapage, for candy fuel. Brown iron oxide has greatest influence here too.

Edited July 17, 2014 by mabuse00