im coating ceramic fibre (wool) with itc-100 ht. has anybody used it over rididizer? thats what i would like to do, but greg odenthal from itc mentioned they "didnt have good experience" with that, whatever it means. my experiments, so far, dont really show any difference, but they were done on small pieces (like 4"x4") so maybe it would be different when doing the whole furnace. without the rigidizer the coating would probably break up, which is not too bad, it woud do its job anyway, but i would prefer to stiffen up the walls. any thoughts? (the search function doesnt alow me to input "itc-100" for some reason.)
What are you going to melt? Makes a difference as high temps will cause some cracking and breaking down of any coating on wool. Satanite is very cheap and very easily repaired. The thermal gain from ITC must be small. I'd go with Satanite as a primary covering---maybe 3 coats each heated to red heat. Then, maybe ITC. I would not use ITC as a primary hot face since it is so expensive and I am unaware of anyone doing it so far. I think Fishbonz (and others) has extensive experience with Satanite. Hopefully he will speak up. I have had 100 hours or more experience with satanite/wool melting iron. In general it did pretty well, but eventually got to a point where it could no longer be repaired. Segmental Blu-Ram has been much much more durable. Also easily repaired. FWIW, Denis
thanks, denis, the idea is to be able to do welding with propane and maybe melt metals on a smaller scale later on. my flame i now over 2500° so it should work. i have the itc-100 already so its really the question if to use the rigidizer or not. i dont mind it cracking but would hate it comming off. i cant use a refractory of any substantial thickness on the walls because the forge would get too small. blu-ram sound interesting for future projects. is this it? https://us.vwr.com/store/product/25718563/blu-ram-hs-plastic-monolithic-refractory
I only have used rigidizer a little bit on wool. So, I have limited experience. I think on raw wool it helps prevent fibers from flying around so that may (or may not) provide some health benefit. But if I am covering the wool with Satanite, I personally dont bother with the rigidizer. That might not be optimal and I will listen to others if they have found it to be useful under a coating. As far as thickness of built up Satanite is concerned, I would guess three coats might be an eighth of an inch thick. Dian, It sounds like you are going to use ITC regardless. So, you will be breaking new ground and I think many of us, myself included, will be interested in how that works. Your link above does point to the material I was referencing. There are other good brands of similar Phos-Bonded rammable refractories. Blu-Ram is an excellent refractory. As you likely know there are various castables that also provide excellent service. Here is where I detailed my Blu-Ram segmental build and some of the rationale for design choices I made: http://forums.thehomefoundry.org/in...fractory-wool-furnace-build-14-dia-bore.1122/ This furnace is still in service. That is the best I have made to date including two castables and one Wool/Satanite that preceeded it. Denis
Sounds like you have a forge. Coat it with Satanite to get a shell over the wool. You'll only need a pound or two. https://www.hightemptools.com/refractorycoatings.html
I think the key take-always from the excellent vid above are: 1) Mix the Satanite to a pretty thin consistency—-like heavy whipping cream as you pour it unwhipped from the carton. 2)Apply enough to just make a thin but opaque coat. 3)Fire it after application to turn it from a wet coat to a brown black hard crust. This cooking can also be done with a weed burner. 4) Not shown, but I think usually done is to paint on one or two more coats firing each coat. The resulting crust is pretty hard and rigid. It can and will crack some but generally will not flake off. If a flake falls off at some poit, just locally reapply 2 or three coats. Good stuff. It is actually intended as a high temp mortar and works great to glue on wool in damaged areas, repair bricks in kilns, etc. Oh, one other thing, dried left over mixed Satanite can be reconstituted days or weeks later. It is not cemetatious, but rather thermal- setting more like a ceramic glaze than a common cement or mortar. Denis
so what i did is prime with 1:3 diluted rigidizer and coat with itc-100 while damp. i also double coated a part* of the forge/furnace with rigidizer and let it dry before applying itc-100. will se if there is any difference. drying now. * its a plug that goes in through the back door and reduces the volume.
Rigidizer and Satanite really don’t need to be dried. I have in the past dried them but in the last year I just paint on the Satanite and cook it. Works just the same. The same is true for another non-cementatious product Bubble Alumina. Since ITC is also non-cementatious it probably also does not require the drying commonly given to dense castable or Castalite. FWIW. Denis
there must have been up to a pint of water in the blanket, so i figured it shoud not evaporate instantly and maybe tear up the coating. the oven took overnight to dry, with a 200w bulb in there.
so i fired the propane furnace and measured 2822° gas temp. originally i was going to do a before itc and after comparison, but i didnt, decided to finally finish the project. i gues it must be doing something, though. i had a piece of mild steel in there and was watching if it would sag under its own weight. well, it didnt sag, the end produced a melt puddle that i didnt see and is now stuck to the itc coated refractory shelf. whats the best way to get ridd of it? heat it up or break it off like it is?
Iron drops and blobs in contact with refractory often result in the iron melting a deep hole in the refractory. I have no experience with ITC. But, with Blu-Ram, it is so resistant that little hole formation, if any, occurs. Maybe ITC will be similarly resistant. If I had Satanite available (I do at my foundry) I’d just paint some on the blob as that seems to stop the erosion otherwise seen. Or maybe ITC would do the same. One way or the other, probably no big deal. Having to touch-up areas of furnace lining is pretty much routine for most folks, I think. Denis
