Sourcing ceramic fiber boards for Walker stove

I am having trouble finding ceramic fiber boards near me in northwest Michigan. I am trying to build the Walker superhot j tube. The website says I need (1.5) 1"x36"x48" Ceramic Fiber Board Sheets.

I just looked on Ebay and could not find any that big. Any idea where I could order these? Or could I use smaller pieces? If so, what is the longest dimension used?

Thanks

Hi Justin,   Glad to hear that your going with one of Matt's cores.

One person I know of that recently made a RMH from one of Matt's cores is Peter Sedgwick. Here is a link to where he was at that stage of building. Not sure if he gave a source for his material.

Advice-RMH-build-Hokkaido-Japan

Another fellow Luke Perkins just posted that he began a new business selling the cores as well: Shippable-Walker-Superhot-Cores

Have you asked Matt? He is a wealth of information and is very happy to share what he knows. We all love him here! A great guy indeed.

Good luck in your hunt!

Ps... I added your post to the Rocket Mass Heaters forum as well to see if we can find someone who may have the answers you seek

Hey Justin;
It looks to me that the longest component is 36" or less.  
Might be easier to find 12 x 36 x 1"  sheets and buy 4?
Of course ,If you order Matt's plan. It will say exact sizes needed.