Hard Brick forge castable coatings?

[Stacy E. Apelt - Bladesmith]

I'll try and sum it all up for you:
1) The bricks you listed are fireplace/wood stove lining bricks. They are designed to take the heat without shattering, and absorb the heat to radiate out into the room.

2) They would need a LOT of heat from a propane burner to heat up to knifemaking temperatures.

3) Wrapping a hard brick forge with kaowool won't change the above issues. It would take a BIG burner and a lot of propane to heat the bricks to 1500F. This is basically how a blast furnace is built.

4) Lining the bricks with a layer of kaowool, a satanite coating, and ITC final coat would work ... but the bricks are just the shell and not doing anything. Any tube of non-flammable material would work just as well. Thin sheet metal, a piece of large pipe, a coffee can, a metal waste paper basket, even rolled up chicken wire would work to hold the wool.

5) Soft firebrick is what many folks use to make a 1,2,4,6 brick forge. All you need is the bricks, some bailing wire or other method to hold them together snug, and a burner. A drill and a 2.5" hole saw will make the holes perfect, but you can cut them with an old steak knife. There are many old threads in Shop Talk on making these simple forges. The search engine in the Stickys will find them for you. There is also a lot of good forge and burner info in the Stickys.

6) Hard fire bricks can be used as the pan liner for a solid fuel forge. There is a lot more to build, though. Lump charcoal (not charcoal briquettes) or forging coal (Pocahontas #3) is the normal fuel.

7) A propane forge is much easier to use ( especially for a beginner) than a solid fuel forge.

 

[cjweaver13]

If you are set on using the hard firebrick you have, then a solid fuel forge is the way to go. I have been using a solid fuel forge made with hard firebrick for years, and it easily reaches forge welding temperatures. This will be dependent on your blower, not the material the forge is made from (solid fuel forges are quite different from propane in this respect - even a hole in the ground can work as a solid fuel forge).

*On the other hand, you can get 6 soft insulating firebricks on Amazon for about $20.

Can't believe I forgot amazon. I was seeing prices for over $30 shipped. Also I have amazon prime. So it seems I will order a 6 pack of those, and use the hard brick for bottom to protect bricks.

 

[Stacy E. Apelt - Bladesmith]

Unless you have the ability to cut the hard brick into 1/2" thick slabs, don't use them for the bottom. They would absorb too much heat and the forge would take a long time to heat up. Best to put the hard bricks down on the top of a metal rolling cart (HF) and put the soft brick forge on top of them. That will give you a place to set hot blades and tongs, as well as keep any forge heat away from the cart.

 

[cjweaver13]

Unless you have the ability to cut the hard brick into 1/2" thick slabs, don't use them for the bottom. They would absorb too much heat and the forge would take a long time to heat up. Best to put the hard bricks down on the top of a metal rolling cart (HF) and put the soft brick forge on top of them. That will give you a place to set hot blades and tongs, as well as keep any forge heet away from the cart.

Never thought of that thank you!

 

[Elijah Perry]

I'll try and sum it all up for you:
1) The bricks you listed are fireplace/wood stove lining bricks. They are designed to take the heat without shattering, and absorb the heat to radiate out into the room.

2) They would need a LOT of heat from a propane burner to heat up to knifemaking temperatures.

3) Wrapping a hard brick forge with kaowool won't change the above issues. It would take a BIG burner and a lot of propane to heat the bricks to 1500F. This is basically how a blast furnace is built.

4) Lining the bricks with a layer of kaowool, a satanite coating, and ITC final coat would work ... but the bricks are just the shell and not doing anything. Any tube of non-flammable material would work just as well. Thin sheet metal, a piece of large pipe, a coffee can, a metal waste paper basket, even rolled up chicken wire would work to hold the wool.

5) Soft firebrick is what many folks use to make a 1,2,4,6 brick forge. All you need is the bricks, some bailing wire or other method to hold them together snug, and a burner. A drill and a 2.5" hole saw will make the holes perfect, but you can cut them with an old steak knife. There are many old threads in Shop Talk on making these simple forges. The search engine in the Stickys will find them for you. There is also a lot of good forge and burner info in the Stickys.

6) Hard fire bricks can be used as the pan liner for a solid fuel forge. There is a lot more to build, though. Lump charcoal (not charcoal briquettes) or forging coal (Pocahontas #3) is the normal fuel.

7) A propane forge is much easier to use ( especially for a beginner) than a solid fuel forge.

I am planing on building a cheep propane forge and the design calls for a lining of kaowool on the top and sides, but for the bottom it says to use soft fire bricks instead. Now fire brick is going to be to expensive for me so is there anything wrong with lining the entire forge with kaowool? Was wondering if it would deteriorate faster than soft fire brick with the constant heat from the above burner.

 

[Stacy E. Apelt - Bladesmith]

No, many/mostforges have the wool all the way around. Just put an extra layer of satanite on the floor after curing the lining ... or do what many of us do and put 1/2" of bubble alumina on the bottom.

You haven't filled out you profile, so I have no idea where you live, but soft fire brick is available most anywhere in the world. Where are you?

 

[Elijah Perry]

Thanks for the info, I live in South Carolina and will soon be adding more info to my profile

No, many/mostforges have the wool all the way around. Just put an extra layer of satanite on the floor after curing the lining ... or do what many of us do and put 1/2" of bubble alumina on the bottom.

You haven't filled out you profile, so I have no idea where you live, but soft fire brick is available most anywhere in the world. Where are you?

Sorry about the profile, I'm new to this forum and will finish filling out my profile soon. The three fire bricks I need cost a lot and I was just wondering if there was another way. Thank you for the feedback, adding a thicker lining to the forge bottom seems like a cheaper and more effective alternative.

 

[Stacy E. Apelt - Bladesmith]

I'm not sure where you are getting your firebricks, but they are $5.5 each for 9X4.5X1" hard firebrick … which is what you want for lining the forge floor. 3" soft brick is $6.

I realize that to a 15 year old, that may be expensive. Knifemaking is not a low cost hobby, and some investment in equipment is necessary to do it properly. A summer of working odd jobs or mowing lawns can buy some of what you will need. It may take time, but if you dedicate yourself to working and saving you can slowly assemble your shop.

High temp tools & refractory has everything you will need for forges and more.
http://hightemptools.com/firebricks.html

Finding a maker or two near you will also help, as many will be glad to share some of their excess supplies and old equipment. If you were up here I would hand you an 80# sack of castolite-30 and some firebricks.