Hi KerryM,
This is perfect, we can mod together!!
I taped all around the seals with foil tape (including around the door) and the change in behaviour of the smoker is remarkable. Before, the whole smoker sort of sat there with smoke pouring out of all the cracks like a building on fire. There was no real suction by the coals and no real flow at the chimney. Now with all the cracks sealed the chimney fires a really nice column of smoke up and you can feel a draught of air being drawn in by the fire, so the 'draw' that people talk about is definitely there.
You really must seal the doors on your smoker its very easy to do and it makes a massive massive difference.
http://www.ebay.co.uk/itm/140649326040? ... 1439.l2649This is the tape I used. I find that applying tape to both surfaces works best so the sealed gap is two layers of tape together. I have placed it around the top door on the firebox and as soon as the postman comes in the morning, im going to put it around the main cooking chamber lid. The tape on the firebox hatch is holding up fine, its not even gone brown, its clearly very high temp tolerant.
There was significant leakage between the firebox and the main chamber too in my smoker. To fix this I took the firebox off, and taped around the hole with the fibreglass tape. I then taped the same path around the hole on the main chamber and remounted it. When I did the bolts up it compressed the fibre tape and sealed the gaps.
The other thing you should do is block up the gap behind the chimney. I used foil tape, but i guess you could probably just stuff foil in the gap until its closed. When I convert the smoker to reverse flow im gonna weld the gap up anyway.
The other thing you should do is turn the grate in the firebox sideways. This raises the grate up, as it naturally sits higher sideways, and it keeps the coals out of the ash. Briquettes, cheap and expensive produce a lot of ash and the last thing you want is your coals to drown in the ash after a few hours (this happened on a test smoke). The smoker comes with three of these grills so you can use them in the main cooking chamber for normal charcoal grilling. I bent the edge up on one of them in the press brake and put it at the front so there is a wire lip that stops coals falling out when you open the door.
The other thing you should do is extend the chimney down, I did this with a bean can, cut both ends off then cut up its length with some tinsnips or similar and roll it tight and shove it up the chimney inside. Make the bean can level with the cooking grid. It helps hold the heat in. Its messy, and again once I get the chimney out to convert it to reverse flow il try and find some pipe of a matching diameter and weld it on for a better fix.
Today I ran one chimney full of cheap tesco briquettes in the fire box. No attention at all, no opening the lids I just left them. At one point I knocked the grate and the ash on the coals fell off so the coals woke up and got hot for a bit, you can see this in the graph below.
This is only maybe a quarter of the coals you would use if you were running the smoker properly so this is a good sign that it gets that hot for that long. The numbers along the bottom are number of seconds and the numbers up the side are degrees C.
https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-prn2/1262608_10151813390137570_610686600_o.jpgPete