BBQ Mailing List Survival Guide
and Smoke-Cooking FAQ

HEAT SHIELDS (3 & 4)

Yowzer Penny! This was both fun and frustrating.

The fact that the firebox opening is *above* the cooking grates on a hondo make heat shielding an interesting puzzle. We had to decide what to do: 1) lower the fb/cc opening, 2) raise the cooking grates, or 3) build our first shield at an angle (slopping downward from the opening and then leveling out). (fb = firebox cc = cooking chamber)

After much thinking, drinking, and head scratching, we decided to do two of our three choices (1 & 2). We decided to lower the opening (a little) and raise the grates. That way our height/depth would not change too much in EITHER direction. One important concern was maintaining enough "headroom" for big cuts of meat.

The easy part was raising the grills. We just measured down about 3/4 inch from the cc door lip and drilled 8 holes (4 in front and 4 in back of cc). In these holes we placed a grill mounting bolt (2 in front and 2 in back x 2 grates). As far as height goes we just tried to keep grills a tad below the cc door lip. We could have gained another 3/4 inch by making it flush, but we wanted to reserve height.

Side Note: On the Brinkman Pro. these holes and bolts are already there. On the New Braunsfels the cooking grates rest on the side of the cc.

Tip: I also found out later that the door thermometer needs height too. Don't expect a good temp reading from that thermometer when it is sitting right on top of a shoulder or butt just below it. I was so busy testing shields that I could not figure out why my door temperature gauge was reading very low. Then it occurred to me, I had a big butt just below it and the end of the thermometer was basically sitting on top of the butt. Not advisable if you want accurate air temps.

HEAT SHIELD ADVENTURE

We used the same thickness steel as the hondo body. We made a total of four shields. Three measure 5" x 16" and the fourth is 6 1/4' x 16". The exact measurements are really dependent upon the amount you "lower" the fb opening.

The first shield is different from the other three shields. It is made up of two pieces of steel welded together, a vertical and a horizontal piece. The vertical piece fits up into the top of the fb opening, thus in effect "lowering" the opening. The horizontal piece extends into the cc and becomes a "shelf" for the heat to "run" along.

MAKING THE FIRST SHIELD

The first shield was the hardest to fabricate. Basically, what we were attempting to do was to drop the top of the fb/cc opening by a small amount (about 2 inches) then add a horizontal piece to create a shelf or channel for the heat for a short run. The result is an "L______" shaped piece of metal. (fb is to the left, cc to the right)

Making the Vertical Piece of the First Shield:

We took a piece of cardboard and held it against the fb/cc opening and traced the pattern of the top 1/3 of the opening.

Next we cut a piece of steel 2" x 9 1/2" (fb/cc opening width at bottom of cut) to match the shape of the top 2 inches of the fb/cc opening. Basically it is curved on the sides to fit the opening.

Getting these curves close enough to fit for testing was very time consuming. I did not want to weld anything in-place right away. Actually, we may never weld at all. They are easier to clean if they are removable.

                 |<------ 7 3/4"  --->|
            
                  ---------------------         ------
               /                        \         ^
              (__________________________)        2"
                                                _____

              |<--------- 9 1/2"  ------>|

As we torched, cut, and welded on the cooker, it sort of felt like I was harming my own child. I could feel pain shooting. . . sorry. I had a relapse.

Tip: Don't clean your smoker prior to doing this work. It's likely to get you a cheaper rate from your welder. The aroma coming from each torch/weld really gets noticed by anyone around the shop. And, guess what? They might be able to weld, but probably couldn't Q if their life depended on it. When the aroma fills the place it is a good time to begin the topic of Q for welding work. Talk ribs, shoulder, brisket...

Making The Horizontal Piece for the First Shield:

Next we made the base (horizontal piece) of the first shield. We measured the width of the cc at 2 inches "below fb/cc top opening" depth, it is 16". The length for the first shield is 6 1/4 inches. For now, this piece remains a solid piece, no draft holes at all. Try and keep this piece as square as you can. It helps a lot.

We next welded the face of the vertical part to the edge of the base piece (the bottom edge of the vertical piece has to be flush with the bottom face of the horizontal piece).

The vertical part fits up, under, and into the fb/cc opening and the horizontal part extends into the cc. This is a little hard to explain. When welded together the first shield looks something like this: "L______" Using this diagram, the fb opening would be to the left and the cc to the right. Pictures...I need pictures.

Getting things square to fit the opening and the fb/cc angles can take a bit of work. The best thing to do is start square and try to stay square. Good grinding equipment (wheel etc.) is a big help.

The Other Shields:

The other shields are made up of the same material, and measure 5" x 16" (cc width). We started out with a total of 4, the Base-Shield plus three rectangle plan ones.

I don't have my notes here to give exact temps prior to using the shields and after so I'll hold off for another writing. I'll give some preliminary ones in a min.

At first, I used the shields without any holes of any kind. I just laid the shields so that they overlapped by about 1/4" and fired it up. This experiment basically moved the hot spot to the end of the last shield. Expected.

Next we knew we had to drill holes or something to let the heat traveling along the run to come up on a "semi- controlled fashion". I really did not feel like drilling/filling holes. Then we thought of a different approach that seems to work.

We cut an elongated "]" out of each heat shield plate. We had to keep the length the same or they'd drop lower in the cc and we'd loose our level with the Base-Shield. However we had a full 5 inches to play with. The entire 5 inches of width is not needed to hold the shield in place.

Note: "The terms WIDTH and LENGTH get mixed up a bit because when in the smoker the shields length is used in reference to the cc's width.

Using the elongated "]" the overall shield length would not change, but the depth of the "]" could to give variable eat/smoke passage as the heat traveled along the shield. So, each shield now looks something like:

                
           ---------/==================/--------     
          |                                     |
          |                                     |
          |           Shield 1                  |
          |           Base Shield               |
          |_____________________________________|





           --------------------------------------     
           L                                   _|     ------
            |                                 |         ^
            |           Shield 2              |         1/8"
           -                                   -      ------
          |_____________________________________|   





           --------------------------------------
           L-                                ___|     -------
             |                               |          ^ 
             |           Shield 3            |         1/4"
           ---                               ----     -------
           |____________________________________|




           --------------------------------------
           L--                              ____|     -----
              |                             |           ^
              |           Shield 4          |          1/2"
           ---                              -----     -----
           |____________________________________|

Drilling holes might work just as well. This works fairly well since smoke and air movement can come up around the shields on their edges. I'd love to have a mini-cam inside with colored smoke to actually see what happens to the air movement. We've thought of drilling holes in the side, putting a light source inside the cc and looking into the holes. Some how, I don't think that will work very well. I think the cc is too small to actually figure out or see any "real" movement of smoke. Anyone have any ideas on how we might see the movement of smoke/air in this configuration?

On Temperatures:

I posted earlier that without food the temps between any given spot (A= fb end, B= middle of cc, and c= right end of cc)is less than 9 deg. This is with each shield spaced approx. 1/2 inch apart from each other. The actuals: A-to-B = 5 deg. B-to-C= 4 deg, and A-to-C = 9 deg.

I'll go over my test notes and post more on different configs. if anyone is interested.

I apologize for this taking so long. Some times we bite off more than I can chew.

ITEM 5:

Welded a 90deg. shut-off valve to the hondo drain.

This one does not take a lot of explanation. We simply welded a piece of water pipe to the hondo drain hole. Then we screwed on a 90degree elbow and fitted a shut-off valve onto it. The advantages to this addition are:

First, I don't have to add a water pan, I can simply add whatever I like into the bottom of the cooker. It works just fine.

Second, When done cooking, I can drain the cooking liquid out very simply, just tip the hondo up a bit, put a drain bucket under the valve and turn it on.

The last advantage was a surprise...it makes cleaning the cooker a lot easier. Now, I simply boil a big pot of water and pour in into the cc and scrub and drain away the grease and other build up into a bucket.

"Patrick Lehnherr" plehnher@isd.net:Smoker Modifications Brinkman New Braunfels Hondo I'd like to bring up a cheap, easy method of decreasing the temperature differential on offset firebox type smokers such as the New Braunfels Black Diamond & Hondo, and the Brinkman brand as well.

I heard this first from list member, Bill Godwin (I think that was his name). Bill used cans to extend the chimney down and to create a heat shield. Another list member, Rod Riplinger, emailed me and said he did the same but with aluminum flashing. He was very happy with the result (and the cost of modifications) so I decided to do the same.

I got the aluminum flashing ($5) from the local home center. I cut some off the roll to extend the chimney to about 1" above the grate. The beautiful thing about using flashing is that it comes in rolls and naturally expands to give you a snug fit in the chimney but it's not permanently attached, allowing you to experiment with the extension height.

I took another piece of flashing and covered the top half of opening between the fire box and the smoking chamber. I used the existing bolts and just punched holes in the flashing to match the pattern.

The one time I've used my smoker since then, the differential was 25-30 degrees F, in strong wind, rather than the 70-80 degree difference I had before. I also had two pork loin roasts sitting 4 inches from the fire box. These roasts stayed there for 12 hours without being moved, turned or flipped and they never did burn or char.

I am amazed at the improvement the modification made and the low cost and ease. I think it took 10 minutes once I found my tin snips.

Regards,
Pat Lehnherr

Bob (the Brisketeer) Godwin NEBBQ@aol.com:Smoker Modifications Brinkman Offset

Mike Roberts won grand champion at the Marlboro Brisket & Rib Challenge last month for several reasons. First, he takes good notes and practices a lot. Second, he improved his smoker when he found out that it was hurting his performance. It's hard enough to smoke good Que without having to worry about a "hot end" or a "cold end", etc.

Taking Mike's changes to heart, I would like to give some tips in the same vein.

I have one of those Brinkman clone smokers with an off-set firebox. It was $160 at Costco three years ago and has already been improved by the addition of two more wheels, welding all of the parts that fall apart during travel, etc.

That hot spot near the firebox had me beat, however. Also, on a 30 degree winter day when I tried to smoke some ribs, I found out that while the thermometer on top read 350 degrees, the temperature on the rack in the middle was only 175 degrees. All the heat was passing out of the firebox, along the top of the cooking chamber, and up the chimney. The chimney started at the top of the cooking chamber, not in the middle or near the bottom like the "real" cookers have.

So, being really cheap, I think I fixed most of the problem at a cost of about 30 cents, as follows:

First, to protect the meat on the "hot" side from the direct radiant heat from the fire-box, I installed a heat deflector made out of a flattened tomato can. Cut along the seam, flatten with a hammer, punch or drill two holes and install over the top half of the fire-box hole on the cooking side. Three bolts hold the top of the fire-box to the cooker. Use the two on the front and back. Just line up the holes in the flattened can with these two bolts and attach right over the existing nuts with 1/4 inch wing nuts. Bend the can in or out as you see fit. Mine just went in naturally at about a 45 degree angle and works great.

Next, cut the top and bottom off a 1 pound coffee can and skip along both sides of the seam. Roll into a roughly cone shape, with the narrow end smaller than the chimney. Try the fit a few times, then pop-rivet in two places. Shove this rough cone up into the chimney. It extends down to about an inch from the cooking grate.

These two improvements made dramatic improvements to the smoker. The temperature is almost constant from one end to the other. In fact, it seems a few degrees cooler just outside the firebox than near the chimney, but not much.

Hope this helps everybody who has one of those small smokers that are designed to look like a trailer mounted rig, but which just don't work the same.

Harry Jiles:Smoker Modifications New Braunfels

I used a gas burner from a fish fryer that I had. It is an oval shaped cast iron burner about 4 by 9 inches. I'm not sure of the BTU output. It will put out a blue flame about a foot high when cranked clear up. I welded together a simple bracket which allowed me to mount the burner in the center of the firebox with the venturi tube protruding out the air damper opening of the firebox. The burner fastens with two 1/4 inch bolts through the bottom of the firebox so it is easy to remove when I need it for the fish fryer or when I want to use wood.

I put the cooking rack back in the firebox in the low position. It sits above the burner about 2 1/2 inches. I put a layer of lava rock on the rack to act as a flame spreader and keep the flame from getting to high in the firebox. I might have to replace the rack with something heavier as it gets red hot and is probably not going to last a real long time.

I put a baffle on the inside of the cooking chamber. It is mounted on the top two bolts that hold the firebox to the cooking chamber. It extends down just below the top cooking rack when it is in the low position and angles out into the chamber until it hits the cooking rack. It shields the meat closest to the firebox from the direct heat and levels out the temperature variance across the cooker. It's not perfect but it helps a lot.

The baffle is a piece of sheet metal 16" long by 7" wide. It has 1" of the width bent at 45 degrees to make a flange for mounting. There is one 1/4" hole in the center for mounting to the top bolt that holds the firebox and cooking chamber together. You have to trim the bottom corners a little to allow for the curvature of the cooker body. It mounts at the top of the fire box and projects outward and down, toward the bottom and center. There is just enough room mount the baffle and get both cooking grate in the chamber.

It takes about 20 minutes to get the whole thing heated up. Then the gas control just has to be cracked less than a quarter turn to hold the temperature at 300 degrees F. This is at the thermometer on the cooking chamber door. I keep the intake and exhaust dampers wide open. The flame from the burner just strikes the bottom of the lava rock and comes up around it about an inch in a few places. The temperature is rock solid and doesn't vary a bit if it isn't very windy. I use a foil pan of wood chips covered with foil with a couple of holes poked in it for smoke.

imm@hi.com (Jim McGrath):Smoker Modifications New Braunfels Hondo

I've had my New Braunfels Hondo for about a year now, and although I've been satisfied with the results, I really had little control over temperature other than the amount of lump charcoal I used. I had to run with the firebox damper fully shut. The Hondo leaked air and smoke like a sieve.

Woodstove gasket material is made from braided fiberglass and I thought this might be a good starting point. I started out with a seven foot length of 3/8" diameter and a tube of gasket cement. I was planning to line the seams of my cooking box, and have the door make a compressing fit. 3/8" gasket is way to thick for the door to close, and that was the smallest diameter I could find. I ended making a butt seal from the outside across the top of the cooking box and uptight against the door flange. I did the same thing across the top of the firebox door. That about used up the 7' of gasket.

I lit off the smoker with a chimney of charcoal to cure the gasket cement and went to bed.

When I lit of my smoker the next morning, I found a world of difference. I could control temperature to within a few degrees with the fire box damper, and was running with the damper about 1 1/2" open to maintain 210F. I was losing no smoke through the top of the smoker box or the fire box. A bit was coming out the vertical seam at the far end of the smoker box door, but most was coming out the chimney.

It had rained the night before, and I noticed that the gasket material had retained a lot of water. Not a good thing, I thought. After the smoker had been running for a few hours and the gaskets were good and dry, I started drizzling them with peanut oil, letting the oil cure for a while, and then drizzle some more. It hasn't rained since, but I don't think the gaskets will hold much water anymore.

I bought another 7' of gasket and plan to continue with the side seams, and probably seal the end door of the firebox completely since I never use it and it has a really bad fit.

Jim McGrath
jimm@hi.com