Duraboard firing?

Christyn Mattson · Post by **Christyn Mattson** » Sun Feb 01, 2004 3:03 pm

Hi! Just got a duraboard from Marty at Centre DeVerre and per his advice, pre-fired to 1450 at 500 dph. Made me realize I need a decent ventilation system! Smoked the heck out of my store. Anyway, I have since used rigidizer and the board has been sitting for 3 days now. Marty said I would need to fire it again after I used the rigidizer. Is this firing to make sure it's dried out or does it have another purpose. I'm anxious to get to using it as I've had thermal shock/breakage with almost all of my pieces 12" and above 3 or 4 layers thick using the regular shelf and varying LOOOOOONGGGG ramps both up and down. I'm hoping this board will help eliminate the shock.
Do I need to fire the rigidized board again before using it? Thanks!

Christyn

GGWLtd · Post by **GGWLtd** » Fri Feb 27, 2004 2:12 am

All carborundum refractory boards and paper will need to be prefired to burn out the binders. Yes it does smoke and stink. No way around it. I use fiber frax paper it does smell when you fire out the binder. It should not smoke. The rigidizer will not keep it from smoking because with or with out it has to have the binder fired out. The fiber paper can be bought from a local furnace supply company cheaper than from a glass distributor. You can fire it once and throw it away. I use it for all my thicker pieces. It also is very useful as a damming material or for stacking as a mold making material and reverse firing of raised designs. You can make these designs cut out with an exacto knife and firing your glass upside down on top of it.

Lynne Chappell · Post by **Lynne Chappell** » Mon Mar 01, 2004 2:29 am

The rigidizer is a ceramic product that has to be fired to achieve its properties. I think 1350F. Then you must kilnwash it or the glass will stick. I use the duraboard without the rigidizer. Glass doesn't stick, a little fiber comes off each time but washes right off the glass. The texture is quite nice on float, acceptable on Bullseye, but rather harsh to the touch on Spectrum.

Marilyn Kaminski · Post by **Marilyn Kaminski** » Mon Mar 01, 2004 11:08 am

I'm also in the process of rigidizing fiberboard. Applied the rigidizer, let it dry , fired it once, flipped it over, fired again. (and holy cow does it smoke! and stink!)

What should it look like when it's done? It's white on both sides, but still seems fragile. Not "crumbly" like it was before, but I can see where it will easily get the edges and corners dinged if I move it much. I guess I thought it would be ... well, more rigid. Or did I not apply enough goop?

And can I cut up the leftover into strips to make baffles and dams?

- Marilyn

charlie · Post by **charlie** » Mon Mar 01, 2004 2:49 pm

it's done when it turns white. yes, it is still fragile after it's fired, and needs to be treated gently. if you tap it, it should ring slightly, whereas if you tap it before firing, it will just thud.

yes, you can cut it up to use as molds, dams, drop rings, or any other kiln use. you still have to do the rigidizing and firing after cutting it though.

Judy Schnabel · Post by **Judy Schnabel** » Mon Mar 01, 2004 7:35 pm

Timing is everything!!!!

I just received my Duraboard from Randy at Jen-Ken but I was unable to open the instructions he e-mailed me.

Do I understand from these posts that you pre-fire the board to 1450
before you put on the rigidizer?

Then you fire again after putting the rigidizer on both sides of the board?

Judy

charlie · Post by **charlie** » Mon Mar 01, 2004 7:38 pm

Judy Schnabel wrote:Timing is everything!!!!

I just received my Duraboard from Randy at Jen-Ken but I was unable to open the instructions he e-mailed me.

Do I understand from these posts that you pre-fire the board to 1450
before you put on the rigidizer? Then you fire again after putting the rigidizer on both sides of the board?

Judy

no. coat all 6 sides with rigidizer, fire. if it's not white on all sides, flip and fire again.

Judy Schnabel · Post by **Judy Schnabel** » Mon Mar 01, 2004 9:48 pm

Another question

Someone suggesting firing on the duraboard could be different than firing on a regular kiln shelf.

What's the scoop?

Judy

Bert Weiss · Post by **Bert Weiss** » Mon Mar 01, 2004 10:12 pm

Judy Schnabel wrote:Another question

Someone suggesting firing on the duraboard could be different than firing on a regular kiln shelf.

What's the scoop?

Judy

Duraboard is an insulator. Mullite is not and is a heat sink. Test