# Insulate MASTERBUILT 20070712 Electric Smoker



## NineInchNails (Mar 29, 2021)

I scored an older Masterbuilt electric smoker 30" for $10 at a yard sale. It's in amazing condition other than the broken thermometer. I made & installed a copper thermowell in place of the thermometer hole. I connected to my PID controller and fired it up for the first time. It was relatively cold and a bit windy. I could not get the temp up to save my life. I didn't feel comfortable covering it with anything and I didn't want whatever I might cover it to reek of smoke. My first smoked whole chicken turned out really great and just finished it in the oven.







I took a close look at this smoker and it appears I can drill out the rivets, remove the top entirely and I assume this would expose the hollow walls. This is just an assumption, haven't confirmed yet. I'm considering doing this and pouring vermiculite into the hollow walls. I presumably could pour vermiculite on the top of the smoker as well then reinstall the top with new rivets. The door is easily removed and I should be able to fill the front door with vermiculite also.

My first concern is that vermiculite doesn't really have a super high R value, but I don't know of any suitable material that really does at this thickness. Any reason why doing this shouldn't make a significant improvement?


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## GaryHibbert (Mar 29, 2021)

I can't really help you on your insulation questions.  What I do if it's real windy or cold is wrap my MES in a welding blanket.
Gary


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## NineInchNails (Mar 29, 2021)

I imagine filling the hollow walls might provide the equivalent of covering with a blanket.


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## bill1 (Mar 29, 2021)

So how hot do the walls get?  It's possible improving insulation will make only an indiscernible improvement in your peak temperature or power bill.  (Why exactly do you want more insulation?) 

That said, it's hard to beat putting a cardboard box over a smoker for a significant thermal improvement.  You need an opening at the bottom and one at the top is all.  If you find this is giving you what you want, there are other approaches that will be more cosmetically appealing. 

Paper's flashpoint is Fahrenheit 451 (thank you Ray Bradbury.)  But most smokers (except at a firebox) don't get this hot so that's one caveat that doesn't apply with an electric Masterbuilt.


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## NineInchNails (Mar 29, 2021)

As the internal temp begins to rise, it would eventually reach a temp that would plateau and rise very very slowly. It was relatively cold and some wind too. Considering that insulating the smoker should help this, I figured why not fill the hollow walls with insulation to achieve this goal. $5 for a rivet tool and several replacement rivets. I already have the vermiculite.


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## NineInchNails (Mar 29, 2021)

oops, double post


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## NineInchNails (Apr 3, 2021)

Well I went and bought a rivet tool & some rivets. All went well, but it wasn't as easy as I thought it might be because the hollow walls were not open from the top so I just had to drill through, funnel in vermiculite and I used silicone to seal the holes. I had to flip the smoker upside down and do the same to the underside  because there were reinforcement beams in the side. The door and the top was easily filled with vermiculite and the re-instillation of rivets was easy.


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## NineInchNails (Apr 3, 2021)

I'll be running this smoker again here pretty soon and I'll see how well this insulation works. In case anyone is concerned, vermiculite can withstand temps up to 2,000F. It's like a natural earth sponge. Really cool stuff. I have a feeling that it will insulate pretty well, allow the temp to rise quicker and maintain temp even in the wind and perhaps cold weather.


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## NineInchNails (Apr 4, 2021)

I just fired it up with nothing in it and the temp went up fast. After it was 92F I began timing it. It took about 14 min to get up to 225F. I think that insulation helped out a LOT.


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## HBFoxJr (Apr 11, 2021)

NineInchNails said:


> I just fired it up with nothing in it and the temp went up fast. After it was 92F I began timing it. It took about 14 min to get up to 225F. I think that insulation helped out a LOT.


Let us know how the chips burn since the element will not be on as much.


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## NineInchNails (Apr 12, 2021)

I get continuous smoke so no worries there. The element turns on plenty. It's just nowhere near as susceptible to external temp & wind. I've only ran this twice, but it might be a bit more efficient with the chips. Before it was insulated it took forever for the temp to rise so it's been a huge improvement.


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