Itc-100; questioning the efficiency.

N

Ninja Blacksmith

Joined
Aug 26, 2012
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Before I finish coating the inside of my new forge with itc-100, I would like to hear from those who have used it before. How much did temperature increase - if at all? Did your firing time decrease, and by how much? Does the temperature spread more evenly throughout the forge, or is there still an extreme hot spot with sub-austenizing temperatures outside of it?

I don't mean to sound like a cynic and skeptic, but I've learned never to count my chickens before they hatch, so to speak. The last time I used refractory, I made the mistake of thinking "all refractories are the same", and lined the old forge with apg #36 - which is awesome for getting a clean and crisp hamon, but inside the forge it dropped the efficiency by God only knows how much. Before applying it, getting a blank up to 1550 - 1600 F, or 1700+ wasn't a problem. After applying the apg coating, anything over 6 or 7 inches would barely break past 1400 F. I'm not doubting the itc, but I want to hear from somebody other than the supplier to make sure I'm not about to make the same mistake.
 
Itc 100 is great stuff When I have used it in a simple venture forge with K-wool and just ITC 100 over the top of it. I had good results applying it by spraying it. That said they say it not safe to not have the k-wool sealed with some type of light refractory. I could reach forge weld temps in this forge.

Brett
 
I'm curious as to why the APG would lower overall temps. It doesnt make sense to me, unless you never gave it enough time to get up to temp. All refractory mortars will change the time to temp of a forge, depending on whether or not they're insulating refractories or not, because they add thermal mass and/or potential insulative value.

APG isn't an insulative one as far as I remember, so it would act as a heat sink, like satanite or most others, and would cause the forge to take time to get up to heat, but it should have helped with even and consistent heat once it was up to temp.


Are you saying that you used *only* APG 36 and no ceramic fiber insulation? Because correct, that wouldn't work, since the APG 36 isn't insulative. Just like using only hard firebricks to make a gas forge wouldn't be efficient, since they're durable and high temp resistant, but not insulative relative to soft firebrick.

Some refractory mortars are highly insulative, and can be used without separate insulation (inswool, etc) when cast in appropriately thick sections, but still, it's better to just use ceramic fiber and then line with a cast or troweled on liner of the insulative refractory.


I don't personally use ITC-100, doesn't seem to be necessary in the forges I've built. Which usually utilize 2" thick of high temp ceramic fiber blanket (2600 or 2800deg stuff, not the 2300-2400, since these are welding forges), and a Kast-o-lite 30 or Mizzou liner, which a Bubble Alumina floor. These are blown forges, so they don't have the "hot-spot" problems of a venturi. They've all been capable of steel melting heat, easily.

I have used APG 36, econocast, and a couple of other cheap non-insulative refractories for patching bad spots on the walls of these forges, and never noticed any problems.

If I was going to use ITC-100, I'd definitely use it over a refractory cement of some type, obviously with that being insulated by ceramic fiber insulation. At a minimum, I'd use the rigidizer for the ceramic fiber, before applying itc-100.




I hear alot of stuff about thick refractory liners "decreasing efficiency", with evidence that it takes a lot longer to get up to temp with that, but what some don't seem to realize is, that while yes, the more thermal mass to heat, the longer it'll take to get to temp initially, generally, the less fuel it'll consume, the more even the heat, and the faster it'll recover from putting cold steel in there, once it's reached that temp and stabilized. If you run your forge for hours at a time like I do, it's a definitely gain and certainly inaccurate to say it's "decreasing efficiency", if anything, it's only decreasing convenience. Fast, and efficient, aren't often synonyms, although since we tend to value our time more than anything, we confuse them as such. Sorry for the little rant. ;)
 
I have found that the best way to achieve and hold good forging and welding temps is sufficient forge insulation. For that, I like 2" of kaowool minimum. A forge with a decent burner the right size, and 2" of even bare blanket can be got to welding heat. Of course, you want to cover your blanket though- I've been using just about 1/8" inch of satanite, with heavier layers in high wear areas, on top of my kaowool the last few re-lines. I find it's very durable and attains welding heats just fine.

I've used ITC 100 in the past, and it did achieve significantly higher heats in a venturi forge, but I've not bought it in a while. Spendy stuff!
 
javand said:
Are you saying that you used *only* APG 36 and no ceramic fiber insulation? Because correct, that wouldn't work, since the APG 36 isn't insulative. Just like using only hard firebricks to make a gas forge wouldn't be efficient, since they're durable and high temp resistant, but not insulative relative to soft firebrick.
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It had 1.5" (I think) thick rigidized kaowool with about 1/8" of apg coating it - not just apg by itself. It's pretty much the same as the new forge build, save that I've tweaked a few tings such as burner orifice placement, and this time the refractory coating is 1/16" itc. It was only after having lined the first one with apg that I did some research and found out not all refractories are intended to reflect heat.

Salem; no kidding. REALLY pricey stuff, and I'm hoping to get what I paid for.
 
Well, I can rest now. Finally got to do a few test runs with the new forge, and it seems fine - though I have had to change the way that I pass a blank through it to avoid hot spot issues. The important thing is that it will evenly heat about 20" max. of steel to 1500+ F in less than half an hour.
 
If it takes half an hour to heat steel up to 1500 degrees you have issues not related to having an ITC coating. Something is not right with your burner. I built a forge from a Harbor Freight air tank lined with 1" wool 1/2" satanite and then coated with ITC with a blown burner and the interior reaches welding temps in less than half an hour.
 
I agree with Barry- something doesn't sound right.

Personally, I think ITC-100 is all it's cracked up to be. My forges are lined with 2- 1" layers of KaoWool or CeraChem (2600F rated ceramic insulation...aka improved KaoWool), a heavy coating of Satanite, and a thin layer of ITC-100.

By putting the heavy layer/layers of Satanite down first, you can get away with using a very thin coating of ITC-100.
 
I'm not sure about it's efficiency, because I switched burners at the same time that I started coating all my forges with ITC100. However, now I do coat all my forges with it and have no problem welding in a simple Atlas Mini Forge. I actually melted my 2350° thermocouple in a forge coated with it.

Here's the biggest problem with ITC-100: Vendors aren't supposed to sell less than a pint at a time. Even though you only need maybe 1-2 oz. to spray coat a forge, you can't buy that amount. That's why I started coating my forges with it. I had leftover from my own forge and can probably coat 20-30 forges from the single pint that I bought.
 
Atlas Knife Company said:
I'm not sure about it's efficiency, because I switched burners at the same time that I started coating all my forges with ITC100. However, now I do coat all my forges with it and have no problem welding in a simple Atlas Mini Forge. I actually melted my 2350° thermocouple in a forge coated with it.

Here's the biggest problem with ITC-100: Vendors aren't supposed to sell less than a pint at a time. Even though you only need maybe 1-2 oz. to spray coat a forge, you can't buy that amount. That's why I started coating my forges with it. I had leftover from my own forge and can probably coat 20-30 forges from the single pint that I bought.
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What equipment do you use to spray coat?
 
I agree with Salem.
2" Kaowool ( Use Hi-Z on welding forges)
1/4" to 3/8" max satanite. Dry and cure properly.
Apply a thin coat of ITC-100. 1/16" is plenty. Even thinner coat will work well. Dry and cure properly.

Yes, a well lined forge will take longer to come up to heat, but will maintain that heat very evenly once the chamber is soaked.

I haven't done any testing, but my head math says that if forging for any longer period of time, a well lined and ITC-100 forge will use less propane, and reach a higher temperature.
 
i used another product but it works great and its quite a bit cheaper. my little stove pipe forge reaches welding temps rather quickly.
soon building a bigger one from a freon tank. it will get a ribbon burner, 2 inches of inswool, cast o lite, then Plistix IR reflective wayne coe sells all this for a real reasonable price.
 
I've since quit using ITC-100. While it definitely makes a forge hotter, in my math it didn't justify the cost over propane. It was selling for almost $200 per pint, that's like 10 tanks of propane. The price has come down drastically since then, but it's still 4 tanks of propane per $70 pint. The math just doesn't add up.

Take into consideration, my forges are insulating firebrick, not wool based. This surely has an effect on the comparison of coated vs. uncoated.
 
Atlas Knife Company said:
I've since quit using ITC-100. While it definitely makes a forge hotter, in my math it didn't justify the cost over propane. It was selling for almost $200 per pint, that's like 10 tanks of propane. The price has come down drastically since then, but it's still 4 tanks of propane per $70 pint. The math just doesn't add up.

Take into consideration, my forges are insulating firebrick, not wool based. This surely has an effect on the comparison of coated vs. uncoated.
Click to expand...


I just got itc 100 from itc coatings site for under 60$ shipped
 
Yeah, it was $100 per pint, then ownership changed hands and it went to $200 per pint. Apparently they changed direction and have since lowered the price. Still, I question the cost/benefit on a well built forge for the average user. It makes sense for a professional like Rick, whose forge runs much more often than mine.
 
Atlas Knife Company said:
Yeah, it was $100 per pint, then ownership changed hands and it went to $200 per pint. Apparently they changed direction and have since lowered the price. Still, I question the cost/benefit on a well built forge for the average user. It makes sense for a professional like Rick, whose forge runs much more often than mine.
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*shrug* my original post was from quite a long time ago, but as a full time, small damascus maker (which is significantly more of my business than knives these days), I still don't use it, and afaik the other guys that are in the same arena as me that I talk to regularly, don't either. It's never seemed to make enough of a difference at 2300+ degrees in our big forges with large ribbon burners (which did make a huge difference for my fuel efficiency in long forging sessions, but I have to keep telling people isn't better for small batch damascus in short forging sessions (nothing is better at everything)).

Plenty of other things do though, extra insulation will pay it's weight in gold for instance, as will the higher temp refractories and insulation. Then again, this is all for 8+ hour long welding sessions at high welding heats in large volume damascus ribbon burner forges.
 
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