|
|
Post by jkirk3279 on Sept 3, 2017 14:44:24 GMT -8
To my astonishment, a commercial supply company in Middlebury IN listed the following:
"Armor Kote, Density 95 lb/ft, 3000 deg F, 1 skid
Grout S15, 1 skid
GS-28 Graphite, 1 skid
TCoat 692M, Density 125 lb/ft, 3000 deg F, 1 skid"
This was in the Free section of Craigslist.
It took some doing and a friend with a car hauler, but we got half a skid each of the S15 Grout and the TCoat 692M.
The reason it was free was, it was from 2009.
Now, is it still usable?
The grout is designed to be painted 1/4" thick on electric heating coils, and will resist 2600F.
The TCoat is listed as a "consumable".
How do I test it?
i am hoping to cast a core.
Maybe inside a 55 gallon drum.
There is about 5400 pounds all told.
Our objective is to build two 4" Rocket stoves, one with batch box.
But I don't know how many pounds of cement a core requires.
My design is to build a greenhouse, about 24' by 12'.
On one wall, I want a LONG cement block platform with a soil box on top.
The Rocket stove would be built into the bench and the flue of course would run through the blocks.
I need to know how much flue is practical.
i can weld up a blower box to push the flue gas up the chimney if necessary, but I sense there's a benefit to a system that runs automatically.
|
|
|
|
Post by jkirk3279 on Sept 6, 2017 19:29:09 GMT -8
Wow.
35 views and no comments.
Let me break it down.
Does Cement go "bad"?
I'm going to cast some firebricks for a test.
Any designs for brick forms?
The "grout" is formulated to be painted on copper induction coils.
I'll try painting it inside a 55 gallon drum to protect the steel.
|
|
|
|
Post by Jura on Sept 6, 2017 23:23:46 GMT -8
The reason it was free was, it was from 2009. Now, is it still usable? I can not find a proper notes from my ceramic chemistry lectures, but I can recall the refractory cements are of no use after 1 year after having been manufactured. Once I find a proof i'll post it update edit: The main component of high alumina cement is CA i CA2 and C12A7 (<12%) that hydratate relatively fast (the CaO adsorbs humidity from the air) C=CaO, S=SiO2, A=Al2O3 |
|
|
|
Post by peterberg on Sept 6, 2017 23:42:34 GMT -8
Cement is a hydrophile material, it attracts moisture. It also react with moisture to form a solid material to say it a simple way. In about a year after production the cement component is hardening by itself solely by the moisture in the air. Most if not all of the refractory materials contains aluminum cement which is hardening much faster as compared to portland cement. I reckon the whole lot isn't usable anymore after 8 years as far as the hydraulic component is aluminum cement.
To test it just mix with water sparingly, cast it in a bucket and wait. When it isn't solid in 24 hours it's useless.
|
|
|
|
Post by Jura on Sept 7, 2017 1:37:54 GMT -8
As usually Peter put it in a simple understandable manner while I was digging too deep again  Cement is a hydrophile material, it attracts moisture. It also react with moisture to form a solid material to say it a simple way. In about a year after production the cement component is hardening by itself solely by the moisture in the air. CaO is strongly hygroscopic but there also occurs a parallel carbonization reaction CaO+CO 2-> CaCO 3 |
|
|
|
Post by jkirk3279 on Sept 7, 2017 10:30:48 GMT -8
Thanks.
This is "magnesia" cement according to the spec sheet.
Does it have the same shelf life?
I read that the production process involves setting the cement, pulverizing it, and baking it to drive the water off.
{shrug}
It makes me wonder if it could be reclaimed.
edit:
We'll test it.
The pallet was tightly stacked, then shrinkwrapped.
I'm a bit fuzzy on how moisture would get IN.
|
|
|
|
Post by coastalrocketeer on Sept 23, 2017 9:36:45 GMT -8
I don't know what magnesia cement is, myself.
Here's hoping it had little enough air circulation and absorbed little enough moisture to still harden nicely!
It may have been a situation of "it's too old for us to use to make a product with a heating element that creates liability for us" rather than anything actually wrong with it.
If they had it in a low humidity environment, and/or successfully kept air from circulating into the bags they could be at or close to original strength... 2009 is a lot of years ago though.
|
|
|
|
Post by Jura on Sept 24, 2017 12:57:15 GMT -8
I don't know what magnesia cement is, myself. Here's hoping it had little enough air circulation and absorbed little enough moisture to still harden nicely! It may have been a situation of "it's too old for us to use to make a product with a heating element that creates liability for us" rather than anything actually wrong with it. Well hope is what you need Magnesium cement is a normal "portland" cement where instead CaO the MgO is used. The trouble is that this oxide is as hygroscopic as CaO. Therefore ppl used to choose the mineral that was available locally. The temp of calcination reaction (CaCO3 + heat-> CaO +CO2 ) is twice as much as the one of reaction for Mangesia. ie. MgCO3 -> MgO + CO2. 400-800 deg. F The MgO cement matrix is ~12 x stronger Raelly looking forward to your experiment results |
|
