Soft Fire Bricks and Flux

[Doug Adams 12]

Are soft fire bricks resistant to flux?

 

Thanks,

Doug

Jn. 3:16

[Dave Stephens 424]

I think they are even worse at resisting it than the hard bricks. Flux just eats stuff. Kinda it's job.

[N. Runals 16]

No.

[GBrackett 18]

They just melt away like candy in your mouth. Even the hard ones have to be changed with time.

[Wayne Coe 56]

Doug, I suggest that you cast the floor as well as the rest of the interior with Kast-0-Lite. The soft bricks don't hold up well to the heat inside a forge, the hard bricks are a heat sink and the Kast-0-Lite is an insulator. The Kast-0-Lite is resistant to flux but the flux will still build up on the floor. Better not to use so much flux, or even none at all. See the threads about Fluxless Welds or Dry Welds. If you are getting a build up of flux in your forge you are using to much flux.

[Elias Larimer 0]

Hey there! Something that I do that is really cheap is I make my own fire bricks out of Perlite an Concreat! The Bricks are not really strong at all, but they are cheap to make and replace! I do have a few ideas that I want to next time I make them that might make them stronger.

[Tyler Miller 0]

Elias Larimer, on 09 Dec 2014 - 03:13, said:

Hey there! Something that I do that is really cheap is I make my own fire bricks out of Perlite an Concreat! The Bricks are not really strong at all, but they are cheap to make and replace! I do have a few ideas that I want to next time I make them that might make them stronger.

Conventional portland cement based concrete isn't refractory and can be explosive due to off-gassing when exposed to excessive heat. I've heard a few stories of potter's kilns exploding because the concrete slab wasn't sufficiently insulated. There are refractory concretes out there, is this what you're using, Elias? I feel in the interest of safety this should be clarified.

 

Edit: I meant to say, painting firebricks with a 50-50 mix of alumina hydrate and kaolin will help to reduce the fluxing action, but soft firebricks really don't stand a chance against flux.

Edited December 11, 2014 by Tyler Miller

[Dan P. 39]

Doug, I suggest that you cast the floor as well as the rest of the interior with Kast-0-Lite. The soft bricks don't hold up well to the heat inside a forge, the hard bricks are a heat sink and the Kast-0-Lite is an insulator. The Kast-0-Lite is resistant to flux but the flux will still build up on the floor. Better not to use so much flux, or even none at all. See the threads about Fluxless Welds or Dry Welds. If you are getting a build up of flux in your forge you are using to much flux.

 

This is interesting. I've always wondered about incorporating a little drain for flux at the bottom of a forge. With a cast bottom that would seem very do-able.