Cheaper and user friendlier Geopolymerization Agents

[sksshel]

More Observations:

- the Geopolymer cuts easily with a hand saw
- when dropped from a height of 2 feet, (an accident) no damage 
- It does not float when put into a sink full of water (I had to try it)
- The surface began to dissolve slightly after the water test.  I have not "fired" the sample.  So it may not be completely cured.  The most cured portion of the sample did not dissolve lending credence to that thought.  
- The strength of the sample is good.  1/2" appox. depth.  Is not brittle.  This particular sample does not contain any rock wool (by accident).  
- I only detected 1 difference between samples 1 - 4, the curing time was slightly faster with more portland cement.  
- no further measurable shrinkage in the first 4 samples. 
- Sample 5 has been removed from the mold now.
- Less shrinkage in sample 5, possibly as much as 50% less.  (too soon to draw conclusions yet)
- Even though the product did not pour nor settle well, the end result compressed nicely into the mold.  I'll know more once it's cured a bit more and I cut it. 

My current thoughts about how to deal with the shrinkage:
- make the molds slightly larger than the target size
- cut and grind the results to the specified sizes. 

[sksshel]

After 2 weeks of curing, final observations on Sample #5:
- Shrinkage was slightly better than the other 4 samples . . . coming in at 7.6% shrinkage
- it resulted in 36 cubic inches of product, .59 liters
- it requires 1.7 times the formula to produce a liter of product
- it easily was sawn with a hand saw
- it weighed 15.4 ounces or 436 grams
- extrapolating the results: 1 liter will weigh about 739 grams, 1 cubic foot will weigh about 99 pounds
- even though the product did not pour nor settle well when vibrated, the results were very satisfactory, no visible voids.  The 2x6 compression method seems to have worked well.  (see pic)

[sksshel]

I am moving on to the prototyping phase of my project.  You can follow it going forward in Cast Double Shoe-box Rocket using User-Friendly Cheap LTGS

Many thanks to all that helped and especially to Karl for his valuable insight.

[esbjornaneer]

Can/Have you got any of your test samples under a torch? What temps do you get on each side? I think Karl talked about plumbers torches reaching higher temps than the ~1200C that the BBR gets to. If you can get a welder's torch on them it is well above the temps in a rocket stove

[branja]

Different gas torches make different energy output per time (power~temperature). Even a common gas burner(cooking stove) for cooking (land gas,butane-propane mix) makes "allot of heat". Also output is different for different gases and different oxygen/air configurations.

Quote:
"A common propane/air flame burns at about 2,250 K (1,980 °C; 3,590 °F), a propane/oxygen flame burns at about 2,526 K (2,253 °C; 4,087 °F),[3] an oxyhydrogen flame burns at 3,073 K (2,800 °C; 5,072 °F), and an acetylene/oxygen flame burns at about 3,773 K (3,500 °C; 6,332 °F)"
link: en.wikipedia.org/wiki/Oxy-fuel_welding_and_cutting

Cheap handheld plasma metal cutters can achieve even more. Try a simple stick welder, it makes more then 1000C/1830F.
Quote: Methane and oxygen burning at a 0.35/1 ratio has a calculated flame temperature of 5,004 °C (9,039 °F) when initial elements are at 25 °C
en.wikipedia.org/wiki/Flame#Hottest_flame_temperature

Energy per time (power) is another matter.

You can ask someone with welding and/or brazing knowledge(mind the technological difference,not the temperature difference) about flame temperatures for a practical standpoint of view.

For fun and hobby ,hottest one : en.wikipedia.org/wiki/Dicyanoacetylene 

[sksshel]

Here are the results of my "Plumbers Torch Test":
- ran the test for 10 minutes on a 1 5/8" sample
- after 5 mins the temp on the other side reached 61^oF
- after 10 mins the temp on the other side reached 82^oF
- my digital thermometer maxes out at 500^oF so I could not get an accurate reading on the "Fire side"
- the colors of the flame appear to be in the 1080-1200^oC range ie: light yellow to white hot
- no visible cracks
- some very small spots of black goo on the surface appeared.  I don't know if this is a sign of the LTGS melting?  or possibly some surface impurities melting.

Should I run the test longer?  Any other suggestions?



Here's the results after the test:

[coastalrocketeer]

Looks similar to the glassification on the surface of my bentonite zeolite mineral wool mix. Longer would be expensive with those little propane bottles but will give you an idea of how the conductivity of the material is over longer periods... In testing a 3.5 cm thick puck of my mix it maxxed out at a bit under 200F after about 15 minutes and remained there for the rest of an hour long test.

I bought a $20 hose at Walmart that lets me hook my torch up to a 15lb bottle, which makes an hour-long test much easier.

PS... What site are you using to host pics? I just got an email from tinypics that their seevice is being gobbled up by photobucket, so may have to redo photos in my previous posts on my build thread.

[sksshel]

Feb 22, 2018 13:40:18 GMT -8 coastalrocketeer said:

Looks similar to the glassification on the surface of my bentonite zeolite mineral wool mix. Longer would be expensive with those little propane bottles but will give you an idea of how the conductivity of the material is over longer periods... In testing a 3.5 cm thick puck of my mix it maxxed out at a bit under 200F after about 15 minutes and remained there for the rest of an hour long test.

I bought a $20 hose at Walmart that lets me hook my torch up to a 15lb bottle, which makes an hour-long test much easier.

PS... What site are you using to host pics? I just got an email from tinypics that their seevice is being gobbled up by photobucket, so may have to redo photos in my previous posts on my build thread.

Is the "glassification" a concern?  Should I do an hour long test or will 15 mins get it done?  I'll need to wait for better weather to do a test that long.   The 5 minutes test I did was indoors. 

I have a similar post on permies.com that I am using for referencing my pics. 

[coastalrocketeer]

Ok... Thanks for the idea on parallel permies posting

[coastalrocketeer]

Here's what the spot that had been torched for an hour looked like


Had a little bit of shrinkage, but only in the parts that got glowing yellow orange... I think with more even heating over entire internal surfaces, it will certainly not be an issue. My successful mix only seemed to get stronger on core burnout of my internal form... Which i accelerated with a blower fan... Parts glassified but all remained intact.
Should have longer term burn tests underway soon as i am almost done mating it to my ceramic fiber blanket lined riser.

[sksshel]

I plan to further "fire test" the recipe on Monday.  I'll fire up my J-Tube rocket with the LTGS piece hung over the riser.  That should accurately replicate the temperature environment.  I can easily run that for several hours. 

[esbjornaneer]

Looking forward to the report.

[sksshel]

I ran the test.  However, I don't think it will prove or disprove anything.  My infrared thermometer maxes out at 500^oF.  The temps inside the J-tube and on the fireside of the geopolymer both were above that temp.  How much above it I don't know.  The Off-side of the geopolymer maxed out at 160^oF.  However, I suspect that much of the heat gain was due to the heat going around the outside.  Without accurate temperature measurements, these results are good but don't really prove much.  I plan to buy a thermostat that will test much higher temps soon. 

No cracks or other malfunctions of the geopolymer were observed.  

[pigbuttons]

Very good results in my opinion. Thanks for working on this and sharing with the rest of us.