cds333

No luck. I let a small rock sit in a vial of water for a week and it is still just a rock. Didn't absorb any water. So you say it didn't go through a chemical change like concrete- so I should be able to re-powder it and reconstitute; I assume I need to dry it first before I put it in the ball mill like I do with other hygroscopic chemicals? What kind of heat are we talking here for curing? Like if I want to dry it out first so I can properly powder it, would putting it in the oven on low cause it to cure? Thanks!

So I can bust it up into small rocks, put it in a ball mill, pulverize to powder, then rehydrate and apply as if it had never dried out and it will work just as good as fresh?

It is the premixed. I didnt see a listing for the dry version. It is still moist, but mostly just a big rock. Concrete undergoes a chemical change when it cures (exothermic reaction) - does ITC also do that? I would assume not since they add water prior to shipping.

I recently got a pint of ITC 100HT and it is already hard in the container. IIRC it is supposed to be pliable right? Is it possible to crush the rock-like substance into smaller pieces and then blend into a paste after adding water? Or does it undergo some chemical change when it hardens? Please advise Thanks!

I had considered that but that would double the cost of the most expensive consumable. Would doubling the kaowool actually give a significant increase in heat retention efficiency such that the costs would balance out? Also is there a known preferred gap between insulation and crucible? Thank you!

Propane with a single 3/4" venturi burner

I am trying to decide between two possible shells for a furnace build. One would be a standard grill-size propane tank and the other would be a slightly smaller green freon tank. I would be using a #3 or #4 crucible which would fit better in the smaller tank, however I think I would prefer the heavier gauge metal of the propane tank as it is easier to weld handles and hinges to. If I were to go with the larger propane tank, how much efficiency would be lost by having a larger amount of air space between the kaowool and the crucible? What are the implications of having such a design? i.e. a small crucible relative to the diameter of the furnace? Thank you!

I read somewhere that the wheel that is on there originally acts as a momentum buffer to counter sudden changes in belt speed when in the treadmill; would that be an asset or a hindrance when using it for a belt grinder do you think? I would imagine it could only help. Also for those of you who have taken it off, what did you use to convert the threaded shaft to a keyed shaft?

Thanks for the welcome! Great to be here. To clarify, it will primarily be used as a furnace. I will eventually be building a dedicated forge as well, probably like the one in the book. I don't do enough blacksmithing at present to justify a dedicated forge, however once I build my belt grinder I will have more use for that. I mainly want to cast aluminum into custom shapes that I can then turn and mill. For the furnace I am thinking about using the cheapest stuff i can find, so I can build a prototype and iron out all the bugs before spending a few hundred on all the best materials. If I can get my burner to work in the geometry of whatever I build then I'll know I have a good design. I don't care if it only works for a few weeks or whatever. My searches have not turned up anything about my question specifically however, if there is anyone out there who has built a furnace out of ceramic wool alone I couldn't find it. (Possibly due to the fact that it has so many different names) So my question is: why does the foundry in the book not need insulation and why does the forge not need refractory? Thanks so much!

From my research I have learned that the difference between making a forge out of ceramic fiber as opposed to castable refractory is that the former heats up quicker and is a more delicate structure, and the latter takes longer to heat up and uses more fuel but stays hot much longer. My goal it to make a small furnace capable of melting aluminum at first, and other metals eventually, that can double as a small forge to heat metal for the occasional blacksmithing project. If anyone is familiar with Micheal porter's book, he describes a propane-tank forge that is made from only ceramic blanket and ITC-100., however later in the book he describes a furnace that is only refractory cement and ITC. I have also heard that it is recommended to add a layer of ceramic blanket outside the layer of castable refractory if you are using it, to keep heat from escaping, (i guess heat likes to travel right through the hard layer?!?) I have seen many different furnace designs, all the way from cheapo homemade portland cement up to the ceramic blanket/kast-o-lite type, and have no idea which is best and for what reasons. Would it be possible to make a crucible furnace out of ceramic blanket and ITC-100 only? Or do I definitely need the layer of kast-o-lite or mizzou for example? What are your thoughts guys? Thanks!