Topic: Did anybody see this the other day?

[Garp]

Looking forward to seeing some pics of the construction ?

[Sverige]

Where a lot of these homebuilt tandoors seem to go wrong is with cracking of the liner material due to thermal expansion and / or moisture ingress while in storage. You might want to consider the expansion moduli of your layers and also how you insulate against liquid water creeping in between uses. Moisture vapour being absorbed during storage is probably unavoidable though, so hopefully it stands up to that.

If you do come up with something which works in the long term and doesn't require a cuddly relationship with the store manager at the local cement works, let us know. I'm sure plenty of us like the idea of a tandoor in the back garden, but I do recall a few have reported problems with their previous homebuilt efforts. Come back in 12 months and tell us if it's still working 

[Ghoulie]

I am well aware I am veering off the line of Jimmys build - but using my concrete technology knowledge, with access to materials Joe Punter would not normally come across, I am confident that by using a special cement with high temp resistance as used in foundry / furnace work (1000 deg C +) and lightweight sintered aggregates in the mix for insulation - this should stand up to the rigours of tandoori work temps.  The internal pot is clay fired type - so this should withstand heat.  I will surround it with another lightweight agg mix similar to base mix - but this time foamed for additional insulation properties.

Being inside a zinc coated steel bin with lid - it will be covered at all times - so water ingress should not be a problem.

I will of course let the whole thing dry out for quite some time before firing it up.

Here's hoping my technology theory works - if not, I can always strip it out and replicate Jimmys firebrick route.

[Ghoulie]

100mm deep base put in using lwt agg mix with heat resistant white alumina SECAR 71 cement.  Leaving to set before putting a similar mix as a 50mm deep ring around edge to sit clay pot on.  May do this tomorrow if base is hard.

[Ghoulie]

Edge ring done with gap left for air entry to charcoal area. 1st snag hit - bin isn't uniformly round at opposite  seams - so need to either grind off some of the pot edges to make fit or cut down a bit to give less radius.

[Ghoulie]

Bit of cutting / edge grinding and pot now fits into bin - sitting OK on top of internal lip.   Need some vermiculite now to fill outside gap between pot and bin  then all set to go.

Pics to follow

[Ghoulie]

new bin & large clay pot lid cut off

[Ghoulie]

bin with 100 mm deep base lwt agg high temp resistant cement cast into bottom

[Ghoulie]

base mix with lip cast on top to receive clay pot - done in same lwt temp resistant mix

[Ghoulie]

pot now ground round edges to fit and sitting on lip - part filled with vermiculite insulating surround