Building the filing cabinet cold smoker

First thing you need to do is get a filing cabinet. You are looking for a four drawer metal cabinet. These are always going cheap or free in the small ads. Mine cost me £15.00 which is really pretty expensive as these things tend to go, but I was impatient to get started. You are looking for a sturdy cabinet in fair condition. It should take two to lift it! If it doesn't is it some modern flimsy thing? You don't want that!

Here is mine with the drawers out.

Drifting a little out of construction order, but you will need the ability to heat from under the bottom of the cabinet. Normally sawdust and heat source will be in the bottom drawer. But our aim is to be able to cold smoke and if your charcoal is fierce you need to be able to remove it to under the cabinet.

However this would leave your sawdust three layers of metal (container, bottom of drawer, bottom of cabinet) away from the heat and this is too much, so a large hole needs to be cut in the bottom of the cabinet. A good jigsaw with a metal cutting blade, or an angle grinder makes short work of this. The hole will also provide an air inlet, and the bottom drawer should be ventilated as well. I did a couple of small grooves with an angle grinder. Fire needs oxygen, but we want smouldering and not a  blazing fire, so be conservative, cutting more holes is easier than filling them in.

To draw the smoke up we need a chimney effect, so we cut a hole in the top of the cabinet, a frying pan spatter guard stops the flies and light rain penetrating, and crude but effect a piece of wood holds this down and can be move to open/close the vent.

 Whilst we are on the subject of drawing the smoke up, we will have limited success with all the drawers intact. The top drawer and the third drawer down must have their bottoms removed. How you do this may well depend on the construction techniques used in your particular filing cabinet. My technique of brute force, chisels and hammers has little to recommend it.

The second drawer down needs to have holes drilled to diffuse the smoke. I think I need more in mine even now, but as said before drilling the holes is easier than filling them in.