Flu Liner

[JACK]

I have read somewhere that normal clay flu liners won't stand up to the heat from a Pompeii oven. So my question is do I need a special clay liner or just the normal like the ones used in fire places?

[david s]

They just need to be insulated. If uninsulated they will crack.

[JACK]

Thanks David.
If the flu liner is insulated that will make it get even hotter. Maybe the insulation makes it heat evenly, and prevents it from cracking.

Thanks again
Jack

[fox]

I have used insulated stainless steel on the ones I have built, I then use a clay chimney pot to cover the stainless.

[JACK]

That's beautiful fox.

Thanks

[david s]

Thanks David.
If the flu liner is insulated that will make it get even hotter. Maybe the insulation makes it heat evenly, and prevents it from cracking.

Thanks again
Jack

Yes that’s correct. It is the difference between the temperature on the outside and the temperature on the inside that sets up a difference in thermal expansion that causes the cracking. The insulation reduces this difference enough to eliminate cracking. The clay itself is quite refractory and has been fired to around double the temperature that you will give it..

[JACK]

Thanks Davids, now I understand and can move forward. I sure don't want to do the liner twice.

[JACK]

While on the subject of insulating the liner, I assume loose fill perlite would be OK for that.

[david s]

Yes. Other options areperlcrete, vermicrete or blanket.

[JACK]

Thanks david s