Vermiuculite board

[Havi]

Are there any specific instructions as to how to work with vermiculite shelf, as opposed / different than mullite [ceramic?] boards???

My Dysson shelf broke, and the bigger shelf
I have is Verm. I wonder if I should do something different that the way I worked with the Dysson??

How long will the vermiculite last?
Do I have to worry about temperatures? not too high, maybe??? The shelf is appx. 1" thick.

I'd be grateful for your responses - - -

Many thanks in advance

H.

[DonMcClennen]

I have been using the same 1" Vermiculite shelf now for 8 to 10 years. Initially I painted rigidizer on both sides. Then I remeber the first firing with empty kiln was somewhat smokey (be prepared to vent studio).. One important step is always provide plenty of support underneath. I space mine up off kiln floor 3/4" with numerous blocks and strips from old kiln helves cut up. I do not kilnwash the shelf....instead I use thinfire or dry powder for textured underside. A 2' x 3' shelf is quite manageable to lift in and out to do your build-up on workbench. I have a second one I bought at same time as original and have never had to use it. The bonus is I can tack stainless steel pins thru fibreboard into shelf to build molds etc...dry powder fills in holes after.

[Havi]

Thanks Don,
That's a great response, and very supportive... You saved me, and saved me a lot of money!
However,
My vermiculite is quite old, because I had been using for years, my Dysson, until it broke. Recently.

So my verm. Is with shelf primer. But did not get thru rigidizing.
Do you think I can do the rigidizing NOW ?..
Do I have to scrap, or sand the kilnwash before rigidizing?

I shall be grateful for your response

From the very bottom of my heart!

[Bert Weiss]

I can't imagine that rigidizing would help vermiculite board, or that kilnwash would hurt it. Relying on paper is certainly a reasonable approach. Don mentions powdering his board to fill in the holes. This makes sense to me. Plain alumina hydrate is more durable than kilnwash that is half EPK (kaolin clay).

[Havi]

Thanks, Bert



HaVi

[Havi]

Some more questions -

Can I dry the rigidized vermiculite in the kiln, or does it have to air dry??

Can I apply kiln wash on the wet rigidized shelf and have them dry together?

Can I dry the kilnwashed vermi. inside the kiln?

At what temp. should any of this be done, if this is possible? For how long????

Can I rigidize both sides of the verm. and kiln dry them?

Thanks!!!!!

HaVi

[Stephen Richard]

Some more questions -

Can I dry the rigidized vermiculite in the kiln, or does it have to air dry??
Bert has already said there is no necessity (or in my opinion, any advantage) to rigidise.

Can I apply kiln wash on the wet rigidized shelf and have them dry together?
Not a good idea

Can I dry the kilnwashed vermi. inside the kiln?
Yes

At what temp. should any of this be done, if this is possible? For how long????
Drying kiln was can be done at 99C, depending on how much moisture you put in it. A mirror over a port hole will fog up if there is still steam coming out

Can I rigidize both sides of the verm. and kiln dry them?
Yes if you must do it at all

Thanks!!!!!

HaVi

[Havi]

Thanks, Richard
- - -
To be on the safe side.
I want the shelf to survive as long as possible.

Meanwhile I have already rigidized both sides


Thanks anyway,
HaVi