Hi Alan,

I think it's great that you're making a cooker! As far as thickness of
walls. The thicker it is, the least chance of rust through, the longer
your going to have it. Plus, the thicker walls help distribute the heat
around once it comes up to temperature.

Also, once the cooker walls reach temp on a thicker wall, it could help
stabilize the temp. fluctuations for a time. But then weight could
become an issue if you want to move it often. I'd say I'd do it with
say, perhaps, 1/4 inch steel.

If your making a wood burner/offset, make sure the firebox is at least
1/4 inch thick (which is where you will probably have the highest risk
of rust through) and make sure it is large enough to hold logs, say the
size of standard fireplace wood. I'd also cut a separate plate to go on
the bottom of the firebox. This will add extra mass and be an extra
buffer against rust through as long as you don't let moisture under it.

On the horizontal offset that I used to have, there was a drain for the
grease. I located a silicon stopper at the hardware store to plug the
hole. Then before cooking, I took a garden hose and added about 2 inch
of water. What it did was act as a heat sink, (better if you can add
hot water rather than cold) and after cooking, I pulled the plug and
all the grease that was floating on top came right out leaving a clean
cooker with a nice thin coating of oil rather a thick layer of grease
that needed scraping out!

Regards,
Mike Willsey (Piedmont)