First off any kind of pit firing is probably not the way to do a real ‘bisque firing’ in the conventional sense, as the pit is not really a kiln, but more like the firebox in a conventional kiln design. In other words, you have widely varying, very uneven temperatures from the get go — which subject your pots to all kinds of extreme thermal stresses — and no insulation to retain and build up the heat needed to vitrify the clay. BTW It’s not temperature per se, but heat work, that transforms clay into ceramics.

With that in mind, both the Weber and my cast iron ‘pit’, and indeed most pit firing techniques, are very poor choices for attempting a conventional firing, including bisque firing. Instead, what you might want to look into is kind of the next stage in the evolution of pottery firing from the open pit, i.e. the building of a simple updraft kiln with bricks, mud, shards, etc.; most probably separating out the firebox from the ware, too, in the process. Here is a book that should help you along the way: Primitive Pottery by Hal Riegger.

As to the temperature reached, I’ve never measured it, but based on what I’ve read the upper range is about 1000F to 1500F depending on whom you ask; though as I mentioned above it’s not the top temperature reached somewhere in the pit that matters — rather, whether and how one can arrive at the desired tempature at a uniform pace in a controllable manner, that’s the real question.

Hope this helped.

RIP Sam. We’ll miss you.

BTW for those of you who would also like to communicate with me directly, the best way to do so is to use the contact form, as it is connected directly to my regular email account, and your message would remain private and not showing up here.

You might want to check out a couple photos of a small temporary brick structure that Eva Funderburgh has built for pit firing: the enclosure and the firing in action.

BTW this is a fairly common way to build a ‘pit kiln’ with bricks — I’ve seen ones that are up to 4′x 8′x 4′ in size, and you can adjust the gaps between bricks to vary the airflow allowed into the structure during firing. The gaps can be plugged with damp clay during the firing, too, if desired.