On Sep 23, 10:49*pm, Tabby wrote:
On Sep 23, 6:57*pm, Tim Watts wrote:





On 23/09/10 18:19, harry wrote:

On 23 Sep, 15:26, Lee *wrote:
Hi All,

I am looking at cast the "trough" of my outdoor BBQ out of
"concrete" (i.e. the bit where you light the charcoal). *Can I used
normal concrete with some reinforcing bars? *I have assumed not but
wondered if anyone had tried it?

I was pointed in the direction of "castable 1400" which is fine to
1400 deg c but this is very expensive (£25/ bag). *I was also
wondering whether I switch regular cement with fondu cement and mix
the concrete as usual would work? *Also, is it OK to use reinforcing
mesh/ bars? *I was wondering whether they would expand within the
concrete as they got hot and crack the whole thing?

Any help appreciated.

thanks

Lee.

No. You need refractory concrete. However it doesn't weather well.
You're best with firebricks that you can replace as neccesary.

As it is only a BBQ and thus used (presumably) infrequently, how about
make the structure of concrete and just loose lay some bricks/clay
tiles/firebricks on the base where most of the heat abuse happens?

I don't think even house bricks will suffer that much and when they do,
just replace as harry suggests... Also, house bricks can be laid with
gaps between them to allow somewhere for the ask to fall and allow some
bottom air flow under the fire.

I don't think the rest of the concrete will see enough heat-times-hours
to degrade for a long time.

Cheers

Tim

Ordinary house bricks survive wood burning, but not coal burning.
Fire cement is far too weak & fragile for this.
I'd assume differential thermal expansion would make steel unusable as
reinforcement for tris app, but I havent tried it,
A far easier material to use for holding the charcoal is EML. It works
fine for more burns than a BBQ will ever see.

NT- Hide quoted text -

- Show quoted text -

Thanks all for your comments. The BBQ is used fairly frequently -
probably every weekend throughout the summer. I initially thought
about a metal box type contruction with an EML type base for the coals
but am keen to make it completely weather resistent and ensure it
looks tidy all the time. From my expience, the metal solutions tend
to warp/ rust etc over time.

Also, the BBQ grill is about 2m long supported on concrete block legs
at each end and across the back if that helps any...

Has anyone ever used fondu or castible?

thanks

Lee.