Bull Heat Deflector Mod, improvement, etc.
- Thread starter JGW
- Start date
Hot rolled mild steels are commonly left with the dark oxidized scale surface intact. Hot rolled steels are stress relieved by the inherent process of rolling in the hot condition. That's why you want to use hot rolled steels for things like griddles (contrary to most economy griddles). If you check out the professional kitchen griddles, they are made with hot rolled steel plate to ensure they don't warp with repeated heating. The temperature for stress relieving (which allows steels with stresses to warp) is the same for thin or thick. I believe that stainless steel 1/4" plate shown is hot rolled then descaled with a grinding process.I don’t doubt it but the amount of heat these produce doesn’t affect a 1/4” thick steel plate.
The other unknown in this part that warps, is the cold forming (bending to shape). It introduces a lot of stresses. Again, when heated above a certain temperature, it allows the part to warp. It has to do with grain boundary slippage and all kinds of other boring stuff.
About to order the RT-700...think this is a great mod and not overly complicated...can please give me the specific piece i should order from www.onlinemetals.com...I am not that familiar with the metal world.I did this same mod on my Traeger (some of you may have seen those pics I posted here) and just did it on my Bull. I really am not sure why the various makers do not spend a little bit more to build a heat deflector that doesn't warp, but that's neither here or there.
I know they say it doesn't really affect the grill, but to me it would seem more heat would come up on the higher end of the warp possibly creating a hot spot in that area. In any case, not a fan of the warped deflector, so I always fix it. I also think the extra steel slightly helps with bounce back as I am sure it retains more heat than the default metal.
Parts
1 - .25 steel plate (12.75" x 9.25) Note: Lowes sells a 12" x 12", and you can use that, but I ordered this one pre-cut from www.onlinemetals.com, mainly because I didn't want to cut the plate myself. They have quick shipping, but due to weight, packaging, etc. the shipping is almost as much as the plate (about $38 together, plate + shipping).
4- 5/16 x 3/4" stainless steel bolts, washers and nuts.
Do some quick measurements for where to drill the hold and bolt it on.If you have a welder, you can certainly weld it on. In the past, I have always used 5 bolts, but I am not sure it's necessary.
I'm going to burn it in before cooking, just to make sure the plate doesn't have anything left on it (cutting fluid, processing gunk, etc.).
Greatly appreciated.
Kevin
Also...will I be able to drill the holes without a drill press?
- Messages
- 913
- Grill(s) owned
- Bull
Kevin, I think I used part # 9610 A36 hot rolled carbon steel plate.
I had it custom cut since it only added a few bucks to the cost. (12.75 x 9.25 inches)
Note: current prices are a lot higher now compared to when I did it. That being said, if you sign up for text messages they’ll knock 15% off.
I had it custom cut since it only added a few bucks to the cost. (12.75 x 9.25 inches)
Note: current prices are a lot higher now compared to when I did it. That being said, if you sign up for text messages they’ll knock 15% off.
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- 986
- Location
- Westerville, OH
You'll get the latest cast iron deflector with your unit I assume?
- Messages
- 499
- Grill(s) owned
- RT-1070
I replaced the mod sheet with 1/8" 9"x9" 304 SS and tested it several times at 500+ for 10-15 minutes at a time. 1/8" did not warp so I will replace the 3/16" with 1/8" from this point. Reduced the weight and thus the heat sink effect. I agree that cold machining could be the cause for the warp of the original d/d. Now that I am happy with the mod can move on to bigger and better ideas, hopefully.
- Messages
- 913
- Grill(s) owned
- Bull
Yeah, the heat sink affect is either a plus or a minus, based on what you are doing. For me....a definite plus, and part of the reason I put a big chunk O' steel there.
- Messages
- 499
- Grill(s) owned
- RT-1070
Suggest you go into test mode and see how the mod has changed the grill temps. I found they run higher and need a little adjustment to get the actual close to the set temp.Yeah, the heat sink affect is either a plus or a minus, based on what you are doing. For me....a definite plus, and part of the reason I put a big chunk O' steel there.
- Messages
- 913
- Grill(s) owned
- Bull
Yeah, but that might be kind of difficult......you'll need cutting fluid, and you'll have to take it slow to avoid over heating the bit, or the drill. If you know someone with a drill press, you might ask if they can do it for you, or let you use it.
- Messages
- 913
- Grill(s) owned
- Bull
Yeah, I did that, but I double check when switching to new pellets too, as some burn a LOT hotter than others.
I did the mod to my 700. Picked up a piece of steel from Home Depot. Measured and cut it myself and drilled it with a regular drill on a bench but just used a goof quality bit and it went through as easy as can be.
I haven’t noticed any type of differences with heating or cooling of it.
(Used all of the specs of original poster)
I haven’t noticed any type of differences with heating or cooling of it.
(Used all of the specs of original poster)
Maybe? 
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