Castable refractory is the way to go for furnace builds, not ceramic blanket

I see everyone pushing ceramic blanket for DIY furnace builds and I just don't get it. I built a small metal melting furnace last year in my garage in Phoenix and went with castable refractory instead. Yeah it cost me about $60 more for a 50lb bag versus the blanket roll, but the durability is night and day. After 20+ melts at 2,000 degrees, my castable walls have zero cracking or flaking while my buddy's blanket-lined furnace already has chunks missing. The blanket also gave off this nasty fiber dust every time he moved his setup. Has anyone else tried both and stuck with castable?

2 comments

2 Comments

rayy8319d ago

Yeah, you're not wrong about the durability but saying ceramic blanket hits 2000 degrees the same way is a stretch - most of that cheap blanket stuff is only rated for 2300F tops and breaks down fast once you push it.

the_sarah19d agoProlific Poster

Hold on though, I mean I've pushed the cheap stuff way past 2300F in my little backyard foundry and it held up fine for a good dozen melts before it started getting crumbly. The real issue isn't the rating, it's how you install it. If you don't compress it right and let it breathe, yeah it'll break down fast. But if you pack it tight and use a rigidizer, that same cheap blanket can handle 2500F plus for a decent while. Idk, maybe I just got lucky with my batch but I've had better luck with the $50 roll from the hardware store than the $200 branded stuff.