Making Kaowool Bricks

[Steven Bronstein]

Based on advice from Jock Dempsey I started making my gas forges with folded kaowool tops. I like having loose soft brick sides so I can rearrange as the jobs require. They are always breaking so I just made modular "bricks" of folded kaowool. I fabricated frames with 1" angle and expanded metal 2.5 x 4.5 x9". I fold the kaowool so it is 3" wide and extends out of the frames 1/2" on the interior side ( making my "bricks 3 x 4.5 x 9") . I coat with satanite and use just I would regular soft bricks. As my soft bricks break I am replacing them with my modular bricks. It is working really well.

 

PDF removed due to copyright.

 

[Frosty]

Steven: Please provide a link to the PDF you reference as copy righted material is not allowed here. Links so long as they aren't commercial sites are fine. If the link is to a commercial site a description of what and were is fine. For example "page 2 of the electrical repair section of the Motors manual Volkswagon edition." 

Does the PDF contain construction details for making the Kaowool "bricks?" Please PM the PDF to me if you don't mind. I'm always interested in builds, especially if they have solutions to problems I had, other than mine.

Your forge is strikingly similar to my too large shop forge though mine is 4 burner and the lid is on a jack to make changing the geometry easy. Below is version 1 before it's first firing, with the failed insulating fire brick lid. The current lid of mine is folded Kaowool with a ITC-100 kiln wash. To avoid confusing folks who've been reading my kiln wash recommendations I no longer  use ITC-100, there are much better and economical products commonly available.

There are some construction details that are visibly different but nothing fundamental. As you, I rapidly discovered insulating fire brick is very short lived at propane forge temperatures, they rarely lasted 2 firings before starting to come apart. I considered making Kaowool and refractory walls but was never satisfied with my results and just bought  IFBs by the case replaced them as they crumbled beyond use. 

The last time I stopped in at Distribution International for a case of IFBs one of the counter guys commented on how fast I was going  through them. When I told him what temps my propane forge generates he was stunned, standard IFBs are only good to about 1650f, NOT 2,700f+. He recommended the new product that was replacing the $11 ea. IFBs with the new Morgan Thermal Ceramics K-26 at a few cents over $3 ea. They're rated for a sustained working max of 2,600f but survive my forge nicely for a dozen firings and cost less than 1/3.

Frosty The Lucky.

 

[Glenn]

PDF removed due to copyright, and Jock Dempsy not allowing links to his site.

[Steven Bronstein]

On 10/26/2022 at 2:27 PM, Frosty said:

Morgan Thermal Ceramics K-26

I will check these out. My kaowool bricks are helpful to me because I am rough on my bricks . I load them in the truck to do demos and not gentle when I am rearranging my forges. For more sedentary setups I can see why these would be great. I think I use to have ones like the K-26 and my smaller forges last a year or two.

[Steven Bronstein]

Here are some progress photos. I wanted to create "kaowool bricks" equivalent to insulating firebricks (IFBS). I am rough on my forges. They get moved around a lot going to do classes and reshaping my forge shapes as my jobs needs change.

I welded angle iron and expanded metal to form open frames 2.5" x 4.5" x 9". I then cut 4 kaowool strips 1" x 3" x 9". These were stacked into the frames and coated with Satanite. The kaowool extends beyond the frames so that the metal does not sit inside the forge interior and is protected from the heat. This results in a "brick" ~3" x 4.5" x 9", the same size as a thick IFB. The Satanite makes it a little thicker and I am ok with that. I could have changed the dimensions accordingly but a little extra wall thickness is not an issue for me. I did the usual cure letting them dry for a day or so and fired slowly. When finished they feel and almost just look like IFBS. but are rugged and will last me many years. Depending on how hard you are on your forges and how much you pay for IFBS will determine if it is worth it to you. I am very happy with the results and no longer have piles of broken soft brick everywhere I turn.

[tinkertim]

Nice implementation Steven.

Hopefully you remembered to rigidise the exposed kaowool on the rear of the bricks, as I didn't see it mentioned anywhere.

I might have to look into doing the same with some of my kaowool offcuts for door bricks, as my IFBs are starting to suffer.

cheers,

Tink!

[JHCC]

I suppose you could dip each piece of wool in the Satanite and then stack them in the frame. That way, each layer would be both completely enclosed and glued to its neighbors.

[Steven Bronstein]

1 hour ago, tinkertim said:

remembered to rigidise the exposed kaowool

Thanks, I put Instuff all the way around to rigidize the kaowool and Satanite on the interieror kaowool face and sides to just cover the expanded metal. Because the outside kaowool face is protected by the expanded metal, I am not too worried about it getting knocked around. If that changes I will cover that with Satanite too.

1 hour ago, JHCC said:

dip each piece of wool in the Satanite

Interesting, I wonder if that would improve the durability of the outside face, rather than just brushing it on. Because the wool is so well protected in the frame, I think the only source of abrasion in getting poked on the interior face

 

 

 

 

Edited October 28, 2022 by Mod34
Removed unnecessary images

[Steven Bronstein]

So 8 months later I thought I would offer a progress report. The kaowool bricks are great. I have a number of gas forges that receive rough treatment from my production work and beginner classes. My forges were all stacked soft bricks and as the bricks have broken ( which was often) I have replaced with the kaowool bricks. As Frosty warned, the Satanite coating did not hold up well to withstand impact and I have switched to Greenpatch 421 and it is great. I just did a recoat of the bricks with the Greenpatch. I am constantly rearranging the shapes of my forges to accommodate my projects and the K Bricks make it easy and I get the benefit of a structural brick that is very impact resistant and insulating too. i have attached some images of the Greenpatch repair. Because it is only a skim coat on the inside of the bricks, a minimal amount of Greenpatch is required and it is a quick operation.

The Kaowool Arch is an easy way to extend the length of my heat and I add or subtract as needed. It is lightweight and easy to pick up and move.

You can see some of the iron frame that is exposed to the heat is degrading but that is the nature of gas forges. Especially after 100s of hours of forge time. As a cost of doing business it is a bargain. 

[Candidquality]

Thanks for the update, I was curious as to how they were holding up.  good to know the upgrade to greenpatch 421 is holding up better.  It is a wear item, but lasting longer still means more time at the fire and less at the workbench on repairs.  

Ant thoughts on adding plistex or similar wash coat to help face durability and reflectance?