Trying an insulating refractory material

[jdelaney44]

Matt, good suggestion. Thought about that actually. You can buy the beads in bulk as bean bag stuffing from Uline. Or you can just buy the un-expanded beads. They plump up nicely with a little steam if I recall from a plastics class I took years ago. Getting them in small amounts is probably the harder part.

Phil, also a good suggestion. Makes total sense.

The sawdust is sounding easier and easier unless this stuff performs well enough to be worth the process.

Latest post - http://redwagonforge.blogspot.com/2011/11/approaching-dry.html

No big news. Couple more pics. They are just getting drier and I'm starting to be able to tell based on color changes. The "oldest" one is clearly whiter than the other two. One thing I didn't say in the blog, it's also starting to sound more like dry clay. It's starting to get a little "ring" to it. The others are thumpy like an old apple.

[jdelaney44]

Did some testing on the seeds. Trying to figure out how hot I should go for the next hold cycle to drive off the remaining water. Here's what I got.

300 for an hour - all the seeds brown a little, no real smell
350 - almost immediately the cracked corn pops, everything else browns pretty dark, smells toasted
400 - some of the other seeds in the mix pop like the pop corn did, everything else gets a lot darker, some of the loose hulls start to char
450 - some more seeds pop, everything starts to char

Note: The millet did not pop at all and it was the last to char badly.

So the answer is 300 F for the max hold temp to drive off the water. If anything in the mix pops, I'm screwed, the whole thing will start to crumble from the inside out.

I'm going to try to bisque one of these Saturday using slow ramp to 300 and a good 2 - 3 hour soak before taking it up to a good bisque temp for the EPK.

[jdelaney44]

Firing the first sample today. It was dry. I cut it in half with a back saw. It cracked straight through about half way into the cut. The center is totally dry. The other two samples had the same resonance to them when I tapped them. So I am sure they are all equally dry.

Firing program

Ramp at 150 F / hr to 300 F
Hold for 2 hours
Ramp at 1000 F / Hr to 2300 F* - 2300 F is about Cone 9
Hold for 2 hours

*Getting 1000 F / hr past about 1500 with this kiln is impossible. I'll be lucky to get 300.

I'm also going to have to monitor the breaker box. This is the first high fire cycle I've done at this house. I'm using a 10 GA copper cable that is tapped directly into a 30 A breaker. Should be OK. The max draw on the kiln is 1800 watts. That's like running two hair dryers at full heat or every light bulb in the house.

Well, we should have burning seeds before too long!

http://redwagonforge...mple-today.html

[jdelaney44]

It's a bust. I think the oil in the seeds got me. OK, well now we know seeds are not an easy fix. Moving on ...

More thoughts on the subject here - http://redwagonforge...1/its-bust.html

Note to self, use link from blogger in the insert picture URL box. Using the Flickr links doesn't seem to work.

[jdelaney44]

Ordering polystyrene beads at:

http://www.foamerica.com/default.asp

Matt's telling me the Perlite has fluxes that will lower the melting point of the compound. Totally makes sense to me.

I still want to give the perlite a try, but given he knows the beads work, I want to do that too so I get to the best mix sooner than later.

Thanks Matt!

-jd

[MattBower]

Perlite makes good loose fill backup insulation.

[jdelaney44]

Well, I got enough of it! That bag from Home Depot has to be two bushels! LOL!

Thanks,
-jd