Myself, I don't know what the properties of the glass must be in order to be used, but I'm certain that @karl already had that sorted out quite some time ago and can provide details if someone is really interested in testing the material out.
Unfortunately, in some cases, obtaining materials (inexpensively) for testing has been a challenge. I've tried to keep to materials that I can purchase locally at a brick and mortar store to avoid high costs of shipping. Several of the components, in the amounts that you would use to build a stove, I've found non cost effective to get shipped. Even powdered perlite, as light as it is, was quoted to cost 2-3 times what the material actually costs to have it shipped (and I'm not talking shipping cross-country either). The costs aren't astronomical but as I'm trying to keep the overall cost of experimenting and (in the long run) the casting of a stove to a minimum, paying a bunch of money for shipping doesn't fit into my equation. I've also found that some places just plain won't sell a few of the products that I was looking for to the general public (at least anywhere near where I live). Other people can get the same product dirt cheap and in bulk with no issue at all. So your location can also play a role.
The paper linked above says: The oligosialate geopolymeric precursor ( binder ) contains 50% by weight of NaOH, KOH equivalent. Thus to obtain the binder mix one part calcined clay with one part lye with just enough water to dissolve the lye and let it rest some hours.
Wet activation by organic acids works with virtually any type of clay. As far I can tell, without expensive laboratory equipment: Reactivity on the level of highly reactive commercial metakaolins like MetaStar 501 or Argical M 1000 is possible.
As I have no red clay cheap white clay was used for the proof of concept. Activation was performed with cheap ordinary vinegar, then the activated clay was mixed with lye flakes 1/1 by dry mass and set aside to rest some hours.
The ready binder was then mixed with nine times more clay by weight, which equals 5% activated clay and 5% lye, and just enough water to make it easy kneadable.
The mixture was molded, dryed and finaly heated to 250°C, which turned the mixture to strong, hard and water insoluble stone, with a dry density of 1.35g/cm³.
The density of 1.35g/cm³ indicates a porosity pretty close to the requirement for an aerogel, despide the low amount of water used as there is no waterglass to fill the space between the clay particles. With slightly more water an aerogel should be possible in this way.
Binder content above 10% should allow to make mixtures liquid enough to be castable.
The LTGS paper claims with lateritic earth 2% to 5% binder are sufficient for water stable bricks. which equals 1% to 2.5% of lye.
It may even work to mix preactivated clay with high amounts of ash from hard wood or straw.
Firewatcher,can you tell me what ratio of binder to clay and aggregate can work without waterglass?
It's quite difficult to actually give a straight-forward answer to your question for a few reasons... First, I've only made two LTGS thus far (my second is drying right now). Second, from the guidance that I've gotten from Karl on all of the mixes that I've tried, the amount of aggregate that is possible to add depends on it's particle size. Since I've only been able to obtain one size of slag to date (actually thanks to YOU posting that you found it at Tractor Supply), I've only used the one size of aggregate to date in any and all of my mixes and it sounds like a finer grade would be better, although the one i'm using has worked fairly well.
The LTGS mix that I already tried and the one that is drying now are the same mix (the first time around, i hadn't followed the mixing instructions and had combined all of the activated clay and then added the lye to that rather than adding the it to only the binder mix first amd letting that rest for a few hours. I have not used waterglass in either of the two mixes. Both mixes were 10% binder 30% aggregate per @karl's suggestion.
Regarding what ratios CAN work, Karl has tried I think 3/1 and 4/1 mixes in his experiments, but has found that the lower ratios are stronger if I remember correctly.
If I missed answering anything, or if you would like more details on anything that I did with my test mixes, please just ask. Honestly though...I know/understand very little on the subject (other than from what Karl has shared in his threads) and I ask Karl for his help/input all the time. I'm much more of a "tester" than a subject matter expert.
Citric acid or acetic acid both work. Use whatever you can get cheaper. 0.167 kg acetic acid is less than 4 liter 5% vinegar.
As a castable LTGS mixture obviously requires additional waterglass for high strenghs, a 10% LTGS mixture with waterglass would suffice.
You may test if you can add about 30% aggregate to a 10% ram mixture without weakening it to much, which would give you 26kg refractory with 1 kg lye.
Karl, In the coming weeks, I may have the opportunity to finally get some clay of known make-up. Per your post's suggestion of adding waterglass to strengthen the material, how much should be added? I imagine that it's dependant on the mix proportions used.
I'm still waiting for my second brick to dry before heat curing, but after going back to my first brick and trying to break it, it breaks more easily than it did before...not sure why.
I would also like to experiment with natural fibers like wool and also feathers, and perhaps carbon bread foam as well, as admixture/aggregate ingredients...
Seems like this stuff he made, (or a similar optimized castable) might be a relatively inexpensive equivalent (or better) replacement for ceramic fiber blanket (and expensive IFB type bricks and boards) in Rocket heater and stove devices...
Post by firewatcher on Sept 18, 2017 13:25:43 GMT -8
Still trying to get the LTGS method to work for me... I've recently tried two recipes...low temperature cured them at around 70 C for 6 hours...waiting for a non-rainy day to "finish curing them" in a camp fire. I've measured temps in a camp fire above 1000 F (around 500 C). I'm hoping that I was able to drive enough of the water out of the test pieces with the low temp cure so that no steam pressure is built up which would damage the pieces internally.
To low temperature cure the pieces, I built a small "oven" out of bricks and suspended them on chicken wire. Below the bricks, I placed 4 "tea light candles" and covered the top with a concrete block. In total, they were heated for six hours. I measured the temperature of the test pieces with an IR thermometer at 70 C.
Post by firewatcher on Sept 19, 2017 12:58:58 GMT -8
After the 6 hours of low temp cure with candles, i performed a camp fire cure (3 hours total - 1.5 hours around the edge of the fire and another 1.5 hours right up beside the coals amd burning wood...let them cool.
Post by firewatcher on Sept 19, 2017 13:03:01 GMT -8
Went to break test them today...broke both with my hands... This has been one of my biggest issues with any mix that I've tried. I know that a given mix doesn't need to be hulk strong, but i'd like to have the peace of mind that there is some degree of strength there as well.
1) took 20g kaolin 6-tile clay and acid activated with 5% concentration vinegar (needed 5% of 20g or 1g acetic acid - 20g of vinegar) 2) took 160g kaolin 6-tile clay and acid activated with 5% concentration vinegar (needed 5% of 160g or 8g acetic acid - 160g of vinegar) 3) I let the acid/clay mix rest overnight (8:00 PM - 4:00 PM the next day - 20 hours total) 4) to the "binder" mix of 20g kaolin 6-tile + 20g of vinegar I added 20g of NaOH...during the "resting period" of 2 hours (that I came up with arbitrarily) it started getting pretty thick, so I added 2mL of water and mixed it in. 5) after the 2 hour (arbitrary amount of time) "resting" period, I mixed together the "binder" (acid activated clay + NaOH) and the remaining acid activated clay. 6) I then mixed in 180g of slag sand (my 1:1) ratio of clay/slag 7) I then mixed in 18g of hydrated lime (10% of the clay by weight)
I have made a vibrating table after watching the you-tube videos that Karl and others have shared, so I put the mix in a plastic mould and let it vibrate on the vibe table until it settled into the mould (it vibrated into the mould pretty well).
I let the mix set in the mould for 4 days in my basement to "solidify" during which time it experienced a fair amount of shrinkage. After the 4-day (arbitrary) solidifying time, I made the make shift "warming chamber" and started to "dry out" the brick using some small candles as the heat source...I left them in the "warming chamber" for 6 hours. The next day, I "camp fire cured" them for 3 hours...the first 1.5 hours around the edge of my fire ring, then the last 1.5 hours right near the burning wood and coals. The following day, I "strength tested" them which means that I tried to "bend them in half". As you saw, this brick broke...
1) took 20g kaolin 6-tile clay and acid activated with 3% concentration vinegar (needed 3% of 20g or 0.6g acetic acid - 12g of vinegar) 2) took 160g kaolin 6-tile clay and acid activated with 3% concentration vinegar (needed 3% of 160g or 4.8g acetic acid - 96g of vinegar) 3) I let the acid/clay mix rest overnight (18 hours total) 4) to the "binder" mix of 20g kaolin 6-tile + 12g of vinegar I added 20g of NaOH...during the "resting period" of 0.5 hours (that I came up with arbitrarily) it started getting pretty thick, so I added 6mL of water and mixed it in. 5) after the 0.5 hour (arbitrary amount of time) "resting" period, I mixed together the "binder" (acid activated clay + NaOH) and the remaining acid activated clay. 6) I then mixed in 180g of slag sand (my 1:1 ratio of clay/slag) 7) I then mixed in 18g of hydrated lime (10% of the clay by weight) + 4 mL of water
I put the mix in a plastic mould and tried to vibrate it on the vibe table, but it was too thick so I had to press and spread it into the mould with my hands.
I let the mix set in the mould for 2 days in my basement to "solidify" during which time it experienced a fair amount of shrinkage...less shrinkage than the rectangle sample, but it was also only allowed 1/2 of the time as the rectangle brick to solidify (2 days vs. 4 days) After the 2-day (arbitrary) solidifying time, I made the make shift "warming chamber" and started to "dry out" the brick using some small candles as the heat source...I left them in the "warming chamber" for 6 hours. The next day, I "camp fire cured" them for 3 hours...the first 1.5 hours around the edge of my fire ring, then the last 1.5 hours right near the burning wood and coals. The following day, I "strength tested" them which means that I tried to "bend them in half". As you saw, this brick broke...
TexasGonzo: Sooooo glad I found this site! Its always rewarding to find such a super group of folks! To any and all, feel free to PM me anytime. Thanks for having me!
Mar 11, 2019 18:56:41 GMT -8
jlmtech: GADGET: CONSIDER USING A JET PUMP INSTEAD OF A BLOWER FAN TO INDUCE DRAFT; NO CLOGGING.
Mar 26, 2019 8:19:28 GMT -8
michaelegan: i am unable to open the sketchup files on my mac. I used sketchup a few years back but apparently the company now requires a subscription. does anyone have any advice/instructions on how to use the program or how to view pictures without spending money?
Aug 20, 2019 18:41:48 GMT -8
mannytheseacow: michaelegan: download AutoCAD student version for free... import .SKP
Aug 23, 2019 13:33:44 GMT -8
topbaza: hi everyone, been searching all over net and this is were i need to be i think!!
Sept 28, 2019 6:16:25 GMT -8
anounaki: Hi, why I cant upload photos when I make new tread to this forum?
Feb 28, 2020 2:09:40 GMT -8
ahansen: photos under 1 mb not possible?
Jun 4, 2020 0:09:21 GMT -8
belgiangulch: Photo's are possible. They must be downloaded elsewhere and the image url (adress) is copyied.
Sept 14, 2020 7:26:15 GMT -8
belgiangulch: While creating a thread click on the small picture in the banner above the reply. A box pops up, paste the image url in the box. Pay no attention to the huge list of numbers and such.When you finish and hit reply your post with pictures will come up.
Sept 14, 2020 7:29:27 GMT -8
deadstarsstillburn: Hi there. I was directed this way by folks on the Permies.com website and am hoping I can get some information on how a total newbie can get started designing, siting, building, and not-dying-in-a-horrible-house-fire with a new RMH in a 160-year old home
Oct 21, 2020 6:52:10 GMT -8
deadstarsstillburn: The people over there recommended either a 6" batchbox or an 8" J-tube. I don't know what those are but am going to try to figure that out. What I need is a blueprint that I can scale to fit the need for my house. I have something likne 5000 square feet
Oct 21, 2020 6:53:00 GMT -8
deadstarsstillburn: but I do not need to heat all of it by any means. probably only need to heat half of that, maybe less.
Oct 21, 2020 6:53:15 GMT -8
deadstarsstillburn: moreover, the house has 3 storeys (large attic) so I assume if I get very efficient heating on the ground floor, that will go a long way toward heating the upstairs as well, no?
Oct 21, 2020 6:53:59 GMT -8
BenAlexanderT: Happy new year everybody. I wish you the best
Dec 31, 2020 15:06:14 GMT -8
Solomon: Anybody in Southern Oregon, in Jackson or Josephine counties?
Jan 16, 2021 21:54:43 GMT -8
gnomedome: i realsie this is from 2009
Apr 14, 2021 8:30:44 GMT -8
gnomedome: i realize this is from 2009 id love to see the photos from this ..as im looking to build a sauna soon similar to this .... if anyody sees this post firstname.lastname@example.org..... the photos in this post did not show up
Apr 14, 2021 8:32:00 GMT -8