View Full Version : Refractory information

Mark Armstrong
03-21-2012, 08:21 AM
Hi everyone,
It's getting time for a rebuild and I am looking for information. I am used to using AP Green products, but they are getting harder, and much more expensive, to get up here in Canada. I have sourced RHI Canada, that has what they say are equivalents to Kast-o-lite 30 and Mizzou castables. The products are called Legrit 28 CD (Kast-o-lite equivalent) and Comprite M60-8 CD (Mizzou equivalent). The spec sheets have very similar ingredient make ups, strengths and thermal conductivities. Has anyone out there used either of these products, or have any other substitutes for Kast-o-lite 30 or Mizzou. What a great source of info this board is. Thanks in advance for any and all info.
Mark Armstrong

Pete VanderLaan
03-21-2012, 09:17 AM
Kast-o-lite 30 is the single best product AP Green ever produced and it still is. I would spend the extra for it. Mizzou is not what it once was and I would consider any 3000F refractory castable to replace it.

Mark Armstrong
03-21-2012, 09:32 PM
Pete, thanks for your thoughts,much appreciated.

Lawrence Ruskin
03-22-2012, 10:38 AM
I found a refractory company in BC tha brought in a couple of bags of Kast o Lite 30 for me perhaps you can find a refractory company back east that will do the same.

I looked at the stuff RHI had to offer but it did'nt look anyway near as good as K30

Pete VanderLaan
03-22-2012, 11:06 AM
I thought RHI bought AP Green years ago. Is that not correct?

Lawrence Ruskin
03-22-2012, 12:20 PM
Yeah they did, but I was just looking in the phone on line and it looks like they made a brief reappearance around here and have gone again.

The local RHI don't seem to want to handle K30 so I found a place that would.

In fact RHI didn't seem to want to help with anything unless you were getting a pallet or more

I tried to find it who those folks who got me those 2 bags of K30 but couldn't find them. Burnaby refractories would know the name of that company, but like I said I would phone around back east.

The local AP Green was very helpful before they were bought out, they would even trade for glass...

Mark Armstrong
03-22-2012, 09:47 PM
Thanks for the ideas Lawrence. I have actually located an AP Green distributor in Ontario, it might be the only permanent location in Canada at the moment. The RHI sales rep has been very helpful, they will sell me just a bag if thats what I want. I am reluctant, though, to try something unknown. But the price difference between the Mizzou castable and the RHI equivalent is over 20$ a 55 lb bag, at the moment if the products are similar I can sure use the cash savings building a new furnace. The Kast-o-lite and the RHI equivalent is comparable in price. I do know some people locally that have just started using some RHI products, (under a year hot time), I was just hoping here on the forum that someone might have had a little longer term experience with the product(s). By the way, where is Lion's Bay? I will be heading up the Sunshine Coast in July.

Pete VanderLaan
03-23-2012, 06:14 AM
It certainly depends on how you are trying to use the castables. Mizzou, or an even better substitute Kruzite would be serviceable in the floor, the door sill etc. I would use 2800F soft brick in the walls with a layer of the mizzou or equal on the hotface as a casting, or to use a kruzite brick for the hot face ( which is what I build with Charlie). The Kastolite 30, not to be confused with Kastolite is excellent in the crown. The crown casting should be no less than 4 inches thick and backed by fiber.

While the castable costs $20.00 more per 55 lb bag, it should not take more than 5-6 bags and ostensibly you are building a tool that should last you five years or more assuming the liner is a replacable pot. I would advise against trying to save $150.00 at this point when you are looking at a tool that may cost you $800 or more per month to operate, or around $50,000 dollars over the five years. I know the Mizzou will work, Kruzite will work better. I don't know for sure about the substitute stuff.

I do think that a plastic refractory clay in the floor would probably be better if you can get it. It's normally pretty cheap but does have a shelf life or it dries out. I have used Blue Coral and Mono T 9 ( no longer available) but the plastics are invariably a localized product. It's just a high alumina clay with pieces of grog the size of peas in it. You pound it in with a hammer, pneumatic or manual. Wear gloves, it slices you.

Rollin Karg
03-23-2012, 09:31 AM
Kruzite 70's are a pretty choice for the floor too.

Lawrence Ruskin
03-23-2012, 11:28 AM
As I said, I looked at RHI's 2800 castable and then hunted down K30.

I hate experimenting building furnaces.

I hate, hate, hate, making expensive, time consuming, mistakes.

And what Pete said on using insulating bricks on the hot face.

um, just for electric melts, and melt at your working temperature.

I just use cullet, which means I don't ever get much above 2000-2050

The hot face bricks look terrible after 12 years, but they still work.

Pete VanderLaan
03-23-2012, 11:50 AM
To be clear: I said use a 2800F soft brick with a layer of mizzou or a brick on the hotface. The brick alone won't stand up well to boron off gas well at all. I used to use 2600F and I don't anymore. 2800 is far more permanent. My old fluorine furnace in Santa Fe had 2600F softbrick exposed and it all looked like melting ice cream.

The only reason I like the plastic refractory on the floor better than a kruzite is no joints in the floor.

Mark Armstrong
03-23-2012, 09:11 PM
Thanks everyone,
I totally agree, I don't want to experiment with new materials in a furnace, it looks like I will go with the tried and true AP Green products. I am running a Correll furnace (vintage 1993) at the moment and looking at a total furnace rebuild along with a gas glory rebuild.