pnut Posted February 9, 2022 Share Posted February 9, 2022 On 2/6/2022 at 5:35 PM, Frosty said: kiln washes aren't IR "reflectors" pnut or they wouldn't get very hot. It absorbs heat energy because it's a poor conductor. I don't mind picky. I actually prefer it to sloppiness. I've heard them called re emission coatings as well which I think is a more accurate description of what it does. Pnut Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 9, 2022 Share Posted February 9, 2022 Yes, IR re-emssive coating is THE term. Or the best I'm aware of. It describes the warm rock from the fire ring you wrap in a towel and put at the foot of your sleeping bag to keep your feet warm too. Warm toes = good night's sleep. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 9, 2022 Share Posted February 9, 2022 I suspect that some manner of Picky Butt insisted on a term like "re-emission" in the first place. Not that it isn't a perfectly good term, as far as it goes. But, lest we go too far, maybe we should respect other terms, that emphasize other important aspects of "kiln washes" "finish coatings" and "sealing coats" as unimportant, which they certainly ain't. Quote Link to comment Share on other sites More sharing options...
DennisCA Posted February 22, 2022 Author Share Posted February 22, 2022 On 2/8/2022 at 8:10 PM, ThomasPowers said: Does Glen ship to Finland? I searched the forums and the answer to that was he stopped because shipping got too expensive. I used to buy a lot from american ebay in the past, until a USPS price hike in 2013, since then I've only bought a handful of items. But the shipping costs have only gotten worse. I am looking at local ceramic stores, I found some kiln shelves there, rated to 2400F. I also found some protective coating meant for the shelves, comes in powder form and you brush it on after mixing with water. supposed to prevent glass from sticking to the kiln shelf, not sure if it's got a use on the firebricks or not. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 22, 2022 Share Posted February 22, 2022 7 hours ago, DennisCA said: ot sure if it's got a use on the firebricks or not. Yes, it is just as useful on firebricks; its what Frosty describes as "kiln wash." The cheapest and easiest of finish coats is kiln wash; it shouldn't be dismissed just cause it ain't fancy enough Quote Link to comment Share on other sites More sharing options...
DennisCA Posted September 29, 2022 Author Share Posted September 29, 2022 I haven't done a single bit of smithing in 2022... This year did not turn out like I had planned... I am attempting to get back up on the horse again. I got a pile of soft bricks still. I have found I can buy ITC-100 here, but it's 66 euros for a liter. The other stuff is a few euros per kg and is made from a mix of aluminum hydroxide and kaolin. I think the ITC is probably a better, but that much better? Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted September 29, 2022 Share Posted September 29, 2022 ITC-100 is not better but different and way more expensive. In the case of a propane forge ITC-100 is not the best, it was designed to use in kilns to keep stuff from sticking. In the propane forge with rapid thermal shock it powders up and will wipe right off. I'm sure Frosty and Mikey will have a better explanation. Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 29, 2022 Share Posted September 29, 2022 What's the name of the product you're asking about for coating the inside of your forge? Hard to compare without taking a look. ITC-100 wasn't formulated for what we need in propane forges it's a release agent so glazes and ceramic clay won't fire to kiln furniture. It scuffs off forge liners if you rub on it at all. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 29, 2022 Share Posted September 29, 2022 I last bought ITC-100 twenty-two years back, and found it insufficient for my needs, without deliberate modification. At what they want for it today, it should be a better product than it is. Plistix 900 costs way less, and is a better product than ITC-100, in my carefully considered opinion. Unless you want to spend a lot of time and expense formulating your own coating, you probably won't find anything better than Plistix 900. Quote Link to comment Share on other sites More sharing options...
DennisCA Posted September 29, 2022 Author Share Posted September 29, 2022 2 hours ago, Frosty said: What's the name of the product you're asking about for coating the inside of your forge? Hard to compare without taking a look. ITC-100 wasn't formulated for what we need in propane forges it's a release agent so glazes and ceramic clay won't fire to kiln furniture. It scuffs off forge liners if you rub on it at all. Frosty The Lucky. The place I am buying from has no name for it, only a description of what it's made of. It's cheap though, 4 euros per kilo. 1 hour ago, Mikey98118 said: I last bought ITC-100 twenty-two years back, and found it insufficient for my needs, without deliberate modification. At what they want for it today, it should be a better product than it is. Plistix 900 costs way less, and is a better product than ITC-100, in my carefully considered opinion. Unless you want to spend a lot of time and expense formulating your own coating, you probably won't find anything better than Plistix 900. Does not exist in europe and cannot be shipped. I have got these two products to choose from. I was hoping someone maybe knew enough they could tell from composition if the cheap product was suitable or not. Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 29, 2022 Share Posted September 29, 2022 I know about ITC-100 in a forge from personal experience. I'd try the cheap stuff and see what happens. Maybe make a small test batch before committing the whole forge. You can make a small enclosure from fire brick and heat it to high yellow heat with your forge burner and see what happens to it. Don't make me tell you to LET IT COOL before handling it after firing! Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 30, 2022 Share Posted September 30, 2022 20 hours ago, DennisCA said: The other stuff is a few euros per kg and is made from a mix of aluminum hydroxide and kaolin. I think the ITC is probably a better, but that much better? ITC-100 is was only a little better than any high-alumina coating when I bought mine--until I separated the colloidal particles from its course particles, by adding small amounts to a half glass of tap water and painting the fine particles that staid in solution on my forge interior; only then did it live up to its hype. Of course, the coarse particles must be thrown out, so once that is done this product terms out to be even more expensive, doesn't it?!? Quote Link to comment Share on other sites More sharing options...
DennisCA Posted September 30, 2022 Author Share Posted September 30, 2022 I read ITC Is kaolin and zirconium, I can buy that on it's own from said shop. I think I shall buy some zirconium silicate while I am at it, and a hard kiln shelf might be good too for a bottom. Quote Link to comment Share on other sites More sharing options...
DennisCA Posted September 30, 2022 Author Share Posted September 30, 2022 I bought the cheap stuff, in addition to 1kg each of bentonite, zirconium silicate and kaolin. Also a kiln shelf to serve as as a bottom for the forge and to make doors from. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted October 1, 2022 Share Posted October 1, 2022 What kind of kiln shelf? High alumina I hope. Quote Link to comment Share on other sites More sharing options...
DennisCA Posted October 1, 2022 Author Share Posted October 1, 2022 It's a kiln shelf for a pottery oven, I figured it was. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted October 1, 2022 Share Posted October 1, 2022 Most kiln shelves are low temperature coredierite shelves 01-3 cone (1623-2048 F) and less expensive than high alumina shelves. The difference is high alumina are 4-7 cone (2167-2264 F) and will resist warping & cracking at the higher temperature in a forge. The next step up in high temperature kiln shelves are 8-14 cone (2305-2530 F) Silicone Carbide. They are ridiculously expensive though. The main thing is to slowly warm up a forge with kiln shelves to avoid thermal shock and dry out any moisture in the shelf. I found out they don't like being shocked by cranking up the burner when first lighting it, oh they won't take being dropped on the floor either. You might ask the supplier what cone the shelf is rated for. The one in the picture was cone 10 rated. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted October 1, 2022 Share Posted October 1, 2022 53 minutes ago, Irondragon ForgeClay Works said: The next step up in high temperature kiln shelves are 8-14 cone (2305-2530 F) Silicone Carbide. They are ridiculously expensive though. Actually, this is what I hoped he didn't buy, because high alumina is seven times as insulating than clay, but what makes clay a poor insulator is its very high silicon contempt; add to this; that carbon is also a poor insulator, and you have a kiln shelf that is excellent for use in a kiln, but a bad choice for the floor of a gas forge. On top of this, I don't think this material would last very long once someone started forge welding Quote Link to comment Share on other sites More sharing options...
DennisCA Posted October 2, 2022 Author Share Posted October 2, 2022 So corderite would be a better material? I could just forego a floor at all and rely on the kiln wash to protect it. But I would like something as doors and such anyway. The shelf was 250x20x13 mm which I think is 6x6x1/2" and 12 euros Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted October 2, 2022 Share Posted October 2, 2022 If you mean to ask whether "corderite" would be better than silicon carbide as the floor of a gas forge, yes. However, I decided on high alumina kiln shelves for floors. Actual corderite would be an excellent choice for a floor facing. I shied away from it, because sellers use "corderite" as a catch-all term. Corderite is what steel melting crucibles were built from for all long time. But the term is simply worthless in the mouth of some bad-faith merchants. High alumina can run from 67% aluminum oxide up beyond 95%. In other words, it has a lower limit. And High alumina kiln furniture is, like actual corderite, fired for extended periods at much higher temperatures than clay pottery. So, if you find legitimate corderite at the prices you mentioned, that is excellent. Even if you didn't get the real deal, you are still in good shape at that price. For even a lower quality alumina kiln shelf, is a better choice than silicon carbide in a gas forge. So, why not use semi-insulating castable refractory (ex. Kast-O-lite 30), if high alumina kiln shelves can be as low as 67% aluminum oxide? Well, lots of people do just than. However, it is had to beat the job of firing that goes into kiln furniture manufacture. Even if we had the patience to fire our forge floor for three days, it would cost more in fuel use than the best kiln shelf. Nevertheless, I applaud anyone who will go to such trouble to attempt to make a little better forge (but than I may have a couple of loose screws too, so...) Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 2, 2022 Share Posted October 2, 2022 Corderite has become a marketer's buzz word and lost it's meaning unless a person can the analysis to evaluate. It's like refractory "cement" the term has become a marketing buzzword so people don't really know what they're getting, some good, some B A D. Silica or alumina spherules (bubbles) are cheap to ship, they hardly weigh anything per pint, 3 - 4oz? Add it to a good high alumina castable refractory and Bob's your uncle. Finding a high temp castable alumina bubble refractory is a regional THING, it's not available in many countries and shipping across borders can be a expensive hassle. Marten of "Monkey forge" in the Nederlands was showing how promising zirconium silicate and Bentone (a ceramics type bentonite) is as a kiln wash and or forge refractory. Bentonite, Bentone, etc doesn't seem to much care about hot borax. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
DennisCA Posted October 3, 2022 Author Share Posted October 3, 2022 I read about something like that which is why I bought a kg of zirconium and bentonite. Said shop also had bubble alumina. As for this piece of kiln shelf I bought, the shop really didn't specify what it was so I have actually no idea what I've ordered, perhaps it can be visually identified when it gets here? Quote Link to comment Share on other sites More sharing options...
Mod34 Posted October 4, 2022 Share Posted October 4, 2022 MOD NOTE: IFI member Latticino's reply about kiln shelves has been moved to its own thread. Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 4, 2022 Share Posted October 4, 2022 Did you post it as a sticky in the gas forge section too? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
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