The Home Machinist!

Ok, thank you both!

It's definately a Hilti:
Although my Polish is a bit off, it seems to be this one:

http://olx.pl/oferta/szlifierka-katowa- ... gkcah.html

1400Watt, not bad for a hand grinder.

Does anyone know what type/brand of grinder this is? Someone gave it to me because it is (was) broken.

It's definately professional grade. I'm thinking Hilti but not too sure... Google left me inconclusive
edit: inline pics

It would be very interesting to know the brandname, especially if it mentions the chemicals used.

If we were firing with gas or oil, we would have the 1" thick outer layer rigidized (it would come wet in poly bags and dry up after you formed it into the furnace liner). Would last 2 plus years in 24/7 chemical plant operation. John Interesting! What 'liquid' was used to soak the kaowool into?

BTW,

I just cut the bar in 2, and the center is soft. So definately chilled on the outsides. Did spark test and compared it to the cast iron I used for the melt, identical sparks. Not a lot of sparks though.

Yeah, your wrong, at least in the way that you are trying to use it. Kaowool melting temperature is 3200F, maximum use temperature is: Kaowool/Kaowool RT** - 2000F continuous, 2300F intermittent Cerablanket - 2150F continuous, 2400F intermittent Cerachem/CeraChrome - 2500F continuous, 2600F intermi...

Melting cast iron in a crucible is, and has always been, a crap shoot, for reasons already mentioned. I understand. But for now it's all that I have. I do believe that, under good conditions (running rich, not to long heating/overheating,...) good results are still possible and repeatable. The prol...

Yes indeed, you have 'white iron' or chilled iron that has little carbon lattice. No amount of reheating will induce carbon into this , and it may be that you cooked the carbon out of the iron to begin with. So a spark test should give me a good indication of the carbon content, right? Are there ot...

The fault is your iron mold. That's how foundries purposely 'chill' the cast iron to make it hard. Sand molds don't cool the iron quickly and don't create the problem. Even then, you don't want to knock the casting out of the mold until it's cooled quite a bit. Pete Okay, so that would mean that th...

Thanks for the interesting replies. I'm gonna reply in depth to each reply when I have more time. I'm going to do some tests (cut a thin piece and try to harden /temper/anneal this, spark test, break it for grain structure,... If it's due to carbide forming, maybe I'll have to reheat it much more......

Rock wool is light weight and suitable for hung insulation up to red heats. Lining an old fridge cabinet can give you a paint oven, or burnout cabinet for de-waxing. Using it as a fire wall or gun target as in a furnace for melting will give you fits, as you are finding out. The furnaces I built I ...