Hey All,
I'm an artist looking to get into hobby scale bronze casting, and I have the option to get some K23 bricks at a good price (about 50 of them for $100).

Trying to do research tonight on whether or not they will work for me, Google kept pointing me to conversations on this forum.. One user, for example, mentioned how his k 23 bricks crumbled in a few months.

Am I crazy to try k23 bricks for bronze casting? It looks like the bricks are rated up to 2300°F.

Bronze melts at 1742°F whereas Iron at 2,800°F, so would I get by at that lower temp?

Thanks for any tips!

What's the pouring temp; not the melting temp?

Have you been over to alloyavenue.com   forums dedicated to backyard metal casting?

Hey Thomas, 
Thanks for the reply -- much appreciated.

I'm so much of a rookie I wasn't even aware of the difference between melting and pouring temp.

Back to Google (and alloyavenue) for homework now.

We have a bunch of people with wide ranging skills here; I took a casting class "out of hours" at a university arts department once, (36 years ago!), and learned the basics and have been using my forge as a casting furnace for small items---mainly knife furniture.

Welcome to IFI, Art Student, Thomas is right and the melting temperature is not also the pouring temperature. That means in my case the melting temperature at 1053°C didn’t mean the super heat pouring temperature at 1150°C. Regarding the soft fire bricks K23 there are strong enough to resist the temperature without physic contact. Remember the bricks are worn able when distressed by contact (in a forge) but quite durable in a foundry we talk about.

Have a look and inspiration at the pictures of our foundry. I use the soft fire bricks (1inch) as a flame face with the backup of 2inch 23K ridgediced Superwool insulation.

However read the advice and tips in the ‘casting section’ of IFI to be prepared of any other Health and safety item. There are many more items to take care about, because melting and casting of bronze are no ‘Monkey business’.

I've probably aid this before but I LOVE your trilobites Hans. Do you have more examples you'd be willing to show us?

Frosty The Lucky.

Frosty, thanks for loving the Trilobites. At this moment I mostly busy to replicate the existing models by giving workshops (Cast In’s ) to friends how went home after finishing, with their own piece of bronze sculpture or device. The models already known like the heel axe, the Venus types, the ammonites, the masks, knuckle bones, fibulas, anvil types etc..

Also busy to build up a stock of ingots made from worn out molten bronze pump impellors to get a good source of pure material. Funny to realise that the impellors pump the excrement’s of thousands of people during their duty in the sewage treatment plant.

After finishing my actual scrap sculpture a steampunk shark submarine, I will go on with bronze casting of a face cast of my daughter Lisa.

Hey Gentlemen, thanks for the replies.

Hans, you share a name with my father! Thanks for giving wisdom just like him 
Thanks for sharing those beautiful images of your rig, and the for the safety warnings -- good call.

 

Do you have any suggestion what configuration I might consider with about 50-60 k 23 bricks?
Would it be a good idea to try and emulate something like yours, or is there a different design you would try if you started from scratch?

 

I'd love to do massive pours (I'm an artist interested in sculpture), but I'll be working in my backyard, generally alone, so large crucibles will probably be a bit out of the question.

 

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The problem I've had with K23 bricks is that I bought some older bricks that had sat around for a while. They had been in a damp area so I dried them and built a small furnace. When I got up to heat for a bronze pour, they just crumbled. Now I've gone to some good castable refractory with ceramic wool for insulation. I picked the wool up at an old foundry that had closed. I would much rather work with Kaowool. 

10 hours ago, Phil K. said:

The problem I've had with K23 bricks is that I bought some older bricks that had sat around for a while. They had been in a damp area so I dried them and built a small furnace. When I got up to heat for a bronze pour, they just crumbled. Now I've gone to some good castable refractory with ceramic wool for insulation. I picked the wool up at an old foundry that had closed. I would much rather work with Kaowool. 

Thanks for the reply Phil.

Sadly these bricks I purchased look like they've been sitting in a shed for a decade, so I will likely have the same problem you're describing 

I guess I'll have to follow your lead eventually. Thanks for tempering my expectations. 

I got some Magnesium Oxide bricks from the same guy, they looked like big chunks of chalk. They worked fine and I'm using them around the shop.