The Smokestack should extend into the Smoke Chamber all the way down to the grates or near the same level with the bottom of the meat.
In addition the metal is not as thick as the more expensive smokers are, which is usually around ¼ of an inch thick. The Silver Smoker seems to be made from 11 gauge steel which is about 1/3 the thickness of ¼ inch steel.
The Firebox is typically smaller that the more expensive brands. The charcoal lays on the bottom of the Firebox that doesn't allow adequate airflow once the ashes start to accumulate.
AND THIN OF THINGS
For instance, imagine a very cheap and thin skillet that you might find at the discount store. We know that there are hot spots that tend to burn the food. On the other hand, a very thick skillet conducts heat better and maintains the heat more uniform. Also consider that a fluctuating fire applied to a thick skillet tends to maintain an "average" temperature much more readily than a thin skillet. I believe this same concept is what is happening to the less expensive smokers.
As we know with the skillet example above, the newer designs don't just add additional thickness or weight, but have unique patented designs. While some of these designs are intended to make better temperature control, I suspect that many of the designs are for the purpose of using less expensive metals (and thinner) and at the same time provide temperature control of the thicker and more expensive metals. We all are aware of the more expensive cookie sheets that are insulated by a gap between two layers of metal to give a more even heating of the top and bottom of the food. We are also aware of the "pizza stone" that maintains even heat plus removing the moisture from the pizza. The typical pizza stone found at commercial restaurants is nothing more than "Fire Bricks."
I also considered the concept of the Big Green Egg smoker. This is an expensive "ceramic" smoker that has rave reviews. Its concept is a well-sealed and insulated smoker.
The thin metal rears its ugly head once again with conductance and radiated heat.
The conductance from the Firebox to the Smoke Chamber makes a hot spot (area) on the left side of the Smoke Chamber. As I said, I believe the thicker metal allows for better dissipation throughout the Smoke Chamber on the more expensive models. Even the more expensive models will exhibit near the Firebox but not to the great degree of the thinner less expensive smokers.
Radiated heat is not limited to "visible" light but for my considerations of tuning, I apply it only to the visible light spectrum and to an extent, the "red" coals. Blocking radiated heat is no more effective using insulation than a thin piece of metal. Radiated heat is the transfer from one object through another object to the final object that receives the heat. For instance, standing some distance in front of a fireplace with glass doors, the "radiated" heat warms you without warming the air around you. If you block that radiated heat with a thin piece of metal between you and the glass doors you will not feel the heat (at least radiated heat). The radiated heat is transferred through the air to the piece of metal. In our smoker's case, we transfer the radiated heat to the metal on the inside of the Firebox and the inside of the Smoke Chamber. In our inexpensive smoker this usually means some radiated heat goes directly to the meat in the chamber as it is completely visible from the Firebox to Smoke Chamber opening.
Of course the convection heat enters at the same opening, so we now have three transfers of heat from one end of the Smoke Chamber.
I approached this as eliminating or diffusing as much of the radiated and conductance as possible, with emphasis on converting it all to convection heat. Of course, all this is done in relationship to a budget in an attempt to avoid the dreaded, "just buy a better smoker" solution. I researched the cost of each solution and made a balance between cost and ease of acquiring the parts. I also approached this in steps that would allow me to continue smoking and monitor the progress of each step. Some of my original ideas just didn't work and the ones that "seemed" to work, is still up for more testing.
The first steps are simple:
The next steps are more of a major undertaking:
In addition, I modified/added a few extra things:
OUTSOURCING & PARTS
Be aware that some "metals" should not be used in a device for food preparation. One example is using galvanized metal. You should not use galvanized metal as it gives off toxic fumes. This is also true about brazing metal instead of welding. If you are not familiar with MIG welding with gas, the gas is only a "shield" and does not burn. In other words it isn't a torch. It makes MIG welding much easier with less cleanup.
The large deflector or baffle requires some bends. I used a metal shop (actually a Heat & Air shop) to make the bends.
I took the Fire Bricks to a friend that had a "tile saw" to cut the bricks into the size that I needed. I also used some of these bricks to mount the temperature probe for the digital thermometers that I used inside the Smoke Chamber. These bricks are relatively soft (somewhat like sandstone) and easy to cut with the right tools.
UP LOOSE ENDS
I touched up the outside with high temperature paint designed for BBQ parts. I scraped off as much of the paint from the inside of the smoker as possible. I found that the "flaking off" of paint on the inside of the Smoke Chamber is easier to dealt with by removing the paint and coating it with peanut oil then "seasoning" it as you would a new smoker.
While the drain and valve makes for a good Smoke Chamber container for water, it also allows much easier cleanup by using the garden hose to wash out the smoker.