- May 30, 2021
- Reaction score
- Sandy UT
- Timberline 850
How much stainless steel did you use for this whole project?I made my first Brisket a while back, it was so incredible I wanted to hug the grill, but didn't lest I end up with a Trager tattoo burned into my chest by the hot logo on the sheet metal! After discussions around insulation here about how it improves efficiency and safety, I dug deep into my Timberline. Also, there are many reported issues with max heat for reverse searing causing paint bubbling in the rear of the Timberline grills.
So my goals were this,
1- Fix the rear overheat issue.
2- Fix the overheated drip collection system.
3- Insulate the entire grill barrel.
I'll detail out what I did in the following posts over the next day or two as I have time. I don't have a metal shop so only used basic tools, vise, hack saw, tin snips, hand drill. I got the stainless steel sheet metal from my local metal fabricator, cut to strips as needed.
Warning, use gloves and a respirator or goggles/face mask while working with the insulation material. While it's ceramic and not asbestos, it is still considered dangerous material to handle.
1- Fixing the rear overheat issue and insulate the barrel bottom.
The dynamics of the airflow inside the grill go like this;
a. The firepot is covered with a baffle, heat blows mainly right and left.
b. 75% of the heat goes up the rear center, front center and up the sides, like a convection oven, recirculating inside the grill barrel.
c. 25% of the heat goes out two small exhaust ports on the right and left, below the drip pan.
d. Those two exhaust ports vent into the rear exhaust box to the outside world.
Looking at the rear of the grill, the exhaust ports are at the bottom right and left of the exhaust box. The grill is "double walled" however, those exhaust ports are single walled and get direct heat blasting into them, then up and out of the box. This is where the paint bubble issues are being seen because it's the hottest spot on the grill. I believe the Timberline 850's get this the worst compared to the bigger models because the grill barrel is shorter so the exhaust ports are closer to the fire pot.
I decided to insulate these corner ports so the hot exhaust could be deflected up into the box and keep these corners cooler. I used 1/2" ceramic wool insulation blanket material, then covered with thin 26 gage stainless steel to take the direct heat.
1- Remove one sheet metal screw from the outside of each each lower exhaust port. replace with a 8-32 stainless machine screw with two nuts, 1 inch long (will trim when done). This will be the post to slide the stainless port protector metal onto and anchor down the material. Insert the screw, add nut inside, then insulation, then sheet metal skin, then 2nd nut.
2- Remove the lower belly pan that surrounds the fire pot.
3- Get the strips of 26gage stainless, make a paper template for the narrow and wide strips, then cut and hand bend them to fit up unto the exhaust ports, drill the hole in each strip to allow them to fit over the stainless bolt, then remove and install the insulation.
This is the ceramic wool material that I used to insulate everything, I also used some foil lined material but I think the basic wool is fine for everything and easier to work with, cuts with scissors.
Amazon.com: Lynn Manufacturing Kaowool Ceramic Fiber Insulation, 1/2" Thick x 24" x 25", 2400F Fireproof Insulation Blanket, 3015E: Home & KitchenAmazon.com: Lynn Manufacturing Kaowool Ceramic Fiber Insulation, 1/2" Thick x 24" x 25", 2400F Fireproof Insulation Blanket, 3015E: Home & Kitchenwww.amazon.com
4- Insulate the lower belly, pack layers of insulation under the drip channel
5- Add the new stainless strips up into the exhaust ports vertically and down into the belly, then add the horizontal ones. (going 2-3 inches inside). Slide them over the stainless screw, add the 2nd nut and tighten enough to hold but don't squish the insulation too much.
6- I insulated the whole belly area, so I had to add additional stainless strips to cover any insulation that the belly pan metal didn't cover, on the right and left sides. Once in place, then replace the belly pan. I had to bend the pan's left side flaps up to allow it to go over the added insulation and stainless covering.
This cured the rear heat issues for me and was the hardest part to do, but wasn't very hard in the end. I can now touch those two corners most of the time, except at max heat but they are much cooler than the stock single layer of steel ever was.
Insulating the rest of the grill was a super easy, read on if you are interested.