I can't lay claim to inventing the drum tandoor... my build was an amalgamation of different builds blogged or described on the internet. I consulted with a variety of people including an artist with kiln building skills, and a professor of Ceramics at the Univeristy of Iowa Art School. I was just sick of eating chitty tandoori chicken and bad naans (I'm Indian), so I figured I would do something about it.
A tandoor usually has a single sort of bell-shaped liner that is set in a brick structire or in the ground. I initially wanted to build a liner myself, but it was getting complicated as I was worried about heat stress and fracturing the liner over time - lead to discussions about types of clay, kaowool, "grog" (stuff mixed into clay to give it some tolerance to heat stress), etc... that where the professor and the kiln-builder came in handy. Then ditched the idea and went for fire bricks... forget how many I used, but got them for $1 and change per brick from a brickyard... the fireplace showroom wanted $6.50 each!! The planter was on sale in Lowe's in January (nobody plants anything in Iowa in January
) for $20 (originally $70+). It was the biggest one they had. Cut off the wide rim so it would fit inside the drum, and cut the bottom to to make an open inverted cone and to form a lid. It was the first time I used and angle grinder, so the bottom cut was kind of crooked as you can see in the first pic
). The drum cost $10, various hardware bits were not too pricey, but I did have to buy some tools (angle grinder, cold chisel, etc) which many folks probably already own. These tools have come in handy building my UDS however.
I will try and describe the build process, but please excuse any details that may be left out... I've got UDS building on the brain right now!
I found a drum for $10 from Jiffy Lube (held windshield washer fluid). Spent a week cleaning it out with everything I could find, till I was satisfied it must be pretty clean. Cut the top off and then put some of the metal hardware in, since it would be inaccessible once the firebricks went in. Wheels (4) on the bottom, handles on either side. Cut the door hatch out of the lid to allow for an intake and big enough to easily clean the ash out. Bolted the hatch in. Then made a mortar of sorts with refractory cement and Perlite (for insulation) and laid a layer down in the base of the drum. Laid one layer of firebrick over that, with regular firecement between bricks. I made sure that the floor of the tandoor was absolutely level with the door hatch so that cleaning out the ash would be easy.
Once it was set, I started started building the walls. After I laid one layer of bricks, I filled Perlite between the drum and bricks. Let it cure then did the second layer. I wanted the top of the inverted planter to rise above the rim of drum by a few inches, so I laid down vertical firebricks accordingly. Laid down DAP high heat or firplace sealant (can't remember exactly what it was called) because I ran out of firecement and didn't want to buy another whole tub of the stuff. Set the planter on it and then filled the gap between planter and drum wall with perlite. I cut a circular sheet of aluminium for a rim to keep the Perlite from flying out, but personally I am not happy with this arrangment. Will look for another solution in time, or if anyone has any thoughts let me know.
You don't need a charcoal basket, but I guess you could use one if you really wanted to. It can be difficult to get a decent sized basket through the narrower top open end, so I just pour a bag of lump into it. The top end has to be narrower so that the heat is somewhat funneled or focused as it moves up the tandoor. Straight walls may make it slightly difficult to make naans. The clay pot has withstood about a dozen or so firings. If it breaks it should not be difficult to chip out and replace. I kept the tandoor in our attached garage during the winter in Iowa and fired it up in the garage when I wanted (opened up the garage door and the window for ventilation).
The first firing was done after seasoning the clay portion with the spinach mix described above. Some say you only need to season with brine to help the naans unstick from the clay walls of the tandoor. More info here http://www.washingtonpost.com/wp-dyn...2005Mar15.html
. I poured in a third of a bag of lump and lit it. Waited a few hours then poured in another third, and the rest after another few hours. The temp should be brought up somewhat gradually to prevent heat stress and risk fracturing the clay pot or the bricks.
A few days later we fired it up to cook. I found the best prices for skewers at www.nishienterprise.com
.... look under tandoor accessories. I looked high and low for skewers and all other skewers were too wimpy or too short or too expensive. I found some turkish skewer that were $7 each... got mine for $2 each and they are nearly indestructible.
Let the tandoor come up to temp. Dangled an oven thermometer on a coat hanger to get the temp in the middle of the oven. The thermometer maxed out at 600*F so I figured the tandoor was hot enough
Put the marinated chicken on the skewers and stuck em in. After about 15 mins we were ready to make naans. Another 10 mins and we were done cooking. It takes about a half day for the whole process, plus about a six-pack of brew, and sometimes a cigar or two.
Everything came out delicious. I will try and post some pron that I have somewhere on my hard drive at home. We have made chicken tikka, tandoori chicken, shrimp, goat kababs among other things. Seekh kababs are tricky... still working on a method for those. Cleanup is fairly easy, once the oven is cool (next evening or later), open the bottom hatch, slide a pan under the drum, stick a broom in from the top and just sweep all the ash out. Also, a fan set up in front of the open door hatch really gets the coals going.
The UDT was a little more expensive to build than a UDS, but its as close to authentic tandoori cooking as you can get this side of the Atlantic. And way cheaper than buying the commercial varieties sold to restaurants. Cooking with it has been very fun and very tasty. My wife makes me feed a morsel or two to the coals when we fire it up to keep it fed and happy. we sometimes lose a naan to the coals, but again, it just keeps our tandoor well-nourished.
Enjoy! I would be glad to help in whatever way I can if any brothers are planning on building one.