eseemann Posted June 20, 2020 Share Posted June 20, 2020 Good Morning All, I hope all is safe and healthy for you and yours. Frosty made a comment in a post about Castable Refractory that sent me down this rabbit hole. Here are some notes and links that you folks might like. Mizzou has been in use in propane forges since I don't know when and lives up to it's rep and then some. It just has about the same insulating properties as the same thickness of limestone. One foot thickness = R1. Th The R-Value is an imperial system unit of measurement (ft^2·°F·h/BTU) Mizzou Castable Refractory 7.4 btu-in/hr-F-ft^2 at 2000 at degrees Limestone 8.74 btu-in/hr-F-ft^2 Kast-O-lite 26 LI Insulating Castable Refractory: 4.0 btu-in/hr-F-ft^2 at 2000 degrees Kast-O-lite 30 LI Insulating Castable Refractory:4.54 btu-in/hr-F-ft^2 at 2000 degrees IFB 23 2 Btu-in/ft², hr, °F at 2000 degrees Kaowool 2.98 BTU-in/hr-ft²-°F at 1800 degrees https://thermtest.com/materials-database http://www.matweb.com/Search/MaterialGroupSearch.aspx?GroupID=11 http://www.matweb.com/search/datasheet_print.aspx?matguid=cb830e74bc69422aa560a7b57494955a https://converter.eu/thermal_conductivity/#1.26_Watt/Meter-K_in_BTU/Hour-Foot-°F https://www.engineeringtoolbox.com/thermal-conductance-conversion-d_1334.html https://www.bnzmaterials.com/miscellaneous-materials/castables/ https://www.bnzmaterials.com/insulating-firebrick/ifb-3200/ https://www.naturalstoneinstitute.org/stoneprofessionals/technical-bulletins/rvalue/ k-Value (Thermal Conductivity) (W/mK) R-Value Equivalent (R)3 (Hr • ft2 • ºF / Btu) Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 21, 2020 Share Posted June 21, 2020 Oh my goodness, why does making YOU think about something make MY head hurt? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 22, 2020 Share Posted June 22, 2020 So what does the percentage of Dolomite in the limestone do to those values? What about Chalk? Quote Link to comment Share on other sites More sharing options...
eseemann Posted June 23, 2020 Author Share Posted June 23, 2020 You ask a very valid question that I can only answer with a slack jawed look. I got no idea but I do know (look at me thinking I know something, I should say I kinda think) that any addition or subtraction of something from another thing will change the properties of the combined whole. Sort of like what I learned from from the periodic videos channel on Youtube. If you try and mold plutonium in a press the plutonium flakes off. But if you alloy plutonium with 2% (or so) of gallium you don't have that problem. 2%, that is almost nothing except if you think about what 1.8% carbon vs 2.8 carbon does to iron, one makes a blade and the other makes a frying pan. Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 23, 2020 Share Posted June 23, 2020 It's an almost reflex of mine to go for the LOOK when talking to folks and it hasn't always worked out well for me. In truth though just skimming the list of cites did indeed give me a headache. Nothing major, I joked it off but my mind no longer embraces keeping multiple things organized at once. I concede I was misusing terms and that's a button of mine. R value doesn't apply to a furnace's insulation value. I'll have to find another or figure out how to make it clear the comparison is a rule of thumb example not literal. You're absolutely right the smallest change can make huge differences and chemistry is nothing but a near infinite number of combinations and possibilities. As I recall we were talking about claying a forge, JABOD I think which isn't really a refractory issue. Thankfully Thomas brought us up short on using lime in a high temp environment. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 23, 2020 Share Posted June 23, 2020 Actually there is a really neat mixture you can use for parging a firepot's surface; lets see now it was a mixture of charcoal, sulfur and potassium nitrate. Mix wet and apply and when you fire up the forge next time you will find that it did a bang up job! Of course I have been know to take the coating for sparklers and mix it in another smith's coal supply at demos---it can be most amusing though I haven't done it very often now that my running away is slowing down! Part of the job here is to tell folks what we may have learned the hard way so they don't have to! A lot of us here tried a bunch of weird stuff when we were young and figured out that perhaps somethings were not a good idea. I sometimes feel very lucky that I'm still counting in decimal! Quote Link to comment Share on other sites More sharing options...
eseemann Posted June 23, 2020 Author Share Posted June 23, 2020 Mr. Thomas, That is sort of like in the early days of AOL and such when it was popular to tell someone to use the secret key combo Alt F4 to get something. They would use it and close AOL. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 24, 2020 Share Posted June 24, 2020 In the UNIX world you could just edit their dot profile to have exit as the last line... Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted June 24, 2020 Share Posted June 24, 2020 Speaking of the old days, it was funny to have +++ in a password, because typing the triple + reset the modem, which disconnected their computer lol, the only way to enterthat 3+ section was to type 2+ then back space then add 2 more. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 24, 2020 Share Posted June 24, 2020 Hayes compatible modems & ATDT; I was lucky enough to avoid the 300 baud acoustically coupled modems; but it was several years before I got a modem with a transfer rate that could write to my monochrome---orange!---monitor faster than I could read it. I was just talking with a Professor here and he was asking if I had missed out on punch card computing. I told him that I had found punch cards a great leap forward as I started programming using a teletype and punched paper tape and it was only when I went to Cornell that I got to use a keypunch and cards! Of course the system I used in HS---an old PDP system, was donated because it was obsolete; but I still got time in on it! My high school was right by two Bell Labs locations and so we had a computer when none of the other schools did! Napier's Bones & the good old days! Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted June 24, 2020 Share Posted June 24, 2020 Boy that brings back memories. In the late '60s early '70s when I was a Parts Manager in a large Cadillac dealership. We used punch tape to communicate with GM for our parts orders and printouts were by dot-matrix printers. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 24, 2020 Share Posted June 24, 2020 Oiled tape chads and shag rugs---need I say more! Of course my Father, an EE, predated digital computers and used to tell me that "Real programmers used soldering irons!" Quote Link to comment Share on other sites More sharing options...
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