Thanks Bill, but for me it's like one of those
bucket list things for me. I have been stuck on
peroxide ever since I saw it go fizz on a cut finger some 55 years ago.
The stuff Aerojet tried selling me were roughly
1/4" round pellets and they want me to buy a 5lb
box at a 6 figure price. and we would have had to
change the whole cat pack configuration to
accommodate enough pellets to get good decomp.
I'm going to try some Mn2O3 and see where that leads.
Robert
At 04:49 PM 8/29/2016, you wrote:
Robert:
With deep respect, "affordable" might be differently understood after a long and ultimately apparently failed effort to use silver screens.
There are other companies that use 405 and finding one to sell (or donate) enough for your purposes might--in retrospect--have been far lower cost.
Given that you have found that it works, if I were to ever use peroxide again I think I would be inclined to baseline 405.
Of course, if I'm going to do *that*, I might as well use hydrazine...recognizing that there is a reason that professionals switched half a century ago....
Bill
On Monday, August 29, 2016, <<mailto:qbert@xxxxxxxxxxxxxxx>qbert@xxxxxxxxxxxxxxx> wrote:
We actually used some and yes it was very good however all we had was a sample and an offer to be able to purchase at a quantity that we could never have used or afforded.
Robert
At 04:17 PM 8/29/2016, you wrote:
I have been told Shell 405 works fine on peroxide but have never heard of anyone using it; the statement came from one of the most experienced liquid rocket engineers in the US, FWIW.
But not perhaps "monolithic" as you mean it.
Bill
On Monday, August 29, 2016, <qbert@xxxxxxxxxxxxxxx> wrote:
I was not aware and don't think that processing screens the way we did it was covered under ITAR since we got it straight from a public book on peroxide rockets and Erik Bengtsson from Peroxide Propulsion
We plated our 20 mesh nickel screens by first cleaning the screens in an acid bath and then thru a wash cycle. They then go into an electro-cleaning solution, through some more washes, then dipped in a pre-activation solution, and we do a copper strike. Back into the acid to etch the copper, backÃÂ thru the cleaning baths and then a silver strike at low amperage followed by the silver plate at high amperage. We then oxidize the silver with liver of sulphur and then heat it in an oven to just below the melting point, (see the following for the reasons, <http://www.peroxidepropulsion.com/article/18>http://www.peroxidepropulsion.com/article/18 ). When the silver is cooled we then do another quick acid bath and wash and then proceed with doing the standard addition of samarium which further enhances the catalization.
Although we have varied on timing and temperatures the stripping problem has stayed with us. In the end we have a relatively stable high performing catalyst with two defects. It can be poisoned and it tends to strip silver on long runs.
Presently I use plated screens processed similar to above and runs less then 10 seconds in the schools 1.5" motor. 1 quick pulse to heat the pack will then give me a 10 second clean run.
BTW the school gets 23 liter containers of a rather pure 90% peroxide which we dilute down to 85% for school demonstrations and after hour tests.
While we are on the Subject, does anyone have a more detailed description of a monolith cat pack like or similar to Aerojets cat packs?
Robert
At 05:38 AM 8/29/2016,
I want to respect proprietary processes--as well as ITAR--so I'm going to be a little vague:
It is my understanding that the silver is electroplated using a very different process than that conventially used for fineà silveer plating.
The Samarian Oxide process involves--as I have seen it--dipping of the screens for a specific period of timeà in a Samarian Nitrrate solution that is kept at a specific temperature; that is followed by warm air drying--again, at a specific air temperature--followed by oven cooking at a specific temperature and for a specific period.ÃàThis is repeated a number of times. Test samples are inspected via electron microscope to verify that the coating is the correct overall thickness and has the correct porosity.
Bill
On Monday, August 29, 2016, Uwe Klein <uwe@xxxxxxxxxxxxxxxxxxx > wrote:
Am 29.08.2016 um 03:30 schrieb Anthony Cesaroni:
If the silver plating process
How is the plating actually done here?
galvanic? that will come off easily.
High current galvanics couldÃÃÂ improve onn that.
what about molten powder application
ÃàÃàÃâÃâàÃà<https://www.castolin.com/>https://www.castolin.com/
or sputtering?
uwe
