Hot Rodding the stove started today

[rover47]

I hope this is close to the topic. But I'm wondering what my Monty has for fire bricks. The sides and bottom are one piece molded of a firebrick type material ( separate pieces). I too notice when things are burning correct they stay very white looking. I used that a sign of how the fire is doing.

 

[Bub381]

Huntindog1 if it's doing it's job it's a good stove and you sound like you're staying warm.

 

[Huntindog1]

Was noticing last night with my stove, as I have insulated behind my fire brick with 1/4" ceramic 2300 insulation and also coated my fire brick and baffle board with ITC-100 to reflect more heat back into the fire box, that loading with sub par wood is not so painful as it used to be. Its nothing magical but I can get the stove into secondary burn mode much easier.

 

[blades]

The key to secondary air is to have it preheated very close to or above the ignition point of gasses, The way a lot of stoves are set up the 2nd air lag time is kinda short to accomplish this. There is of course a cost consideration in this as well. Way back I remember reading about various methods used to improve the efficiency of the old smoke dragons. People would add a good sized ( length for lag time) coil at the top of the fire box ( some were internal ,others external either way seemed to work fairly well) one end intake other connected to re-burn tube/s. The high temp (2300+) insulation above the tubes was to keep from a melt down and of course help hold higher temps in the fire box. Nothing new in this as the mfg world has been using what is called scrubbers on exhaust stacks for years active and catalytic.

 

[Huntindog1]

Just made another mod to my Wood Stove.

Previously I put 1/4" 2300 deg ceramic insulation behind my firebricks. Then I also coated my firebrick with a ceramic reflective coating used in the Kiln industry. All to make my fire box more efficient at maintaining temps at lower input air settings thus keeping the secondaries still firing off at lower burn rates. The idea is that most of your heat radiates out the front and top of the stove so the extra insulation wont hurt. Even after these mods the stove still radiates heat out the back and side a plenty.

What I did this time is I took out the 1/2" ceramic baffle plates up in the top of the stove that sits on top of the 4 secondary air tubes in the top my stove. I also got into the top of the stove thru the 6" flue exhaust and unscrewed the 3 metal pieces that hold down the 1/2" ceramic blanket. All 3 metal hold downs were kept in place by one screw, so easy removal. So the stove has a 1/2" ceramic baffle boards and on top of that is a 1/2" ceramic blanket. The blanket is over sized to cover the over where the baffle boards meet the side of the stove as up there in the top of the stove is a ledge made from the square tubing that delivers the preheated secondary air to tubes. The ceramic blanket runs over far enough rest on the ledge and cover the small gap where the baffle boards meets the side of stove.

From my previous project I had extra, 1/4" 2300 deg ceramic insulation. when I took out the current blanket I used it to measure and cut two more same sized blankets. What I am doing is adding more insulation to the top of the baffle boards to hopefully keep the heat higher up around the secondary air tubes where the heat is needed to keep secondary flames firing during extra low stove settings.

So now I had two extra blankets that will add another 1/2" of insulation but since I had two 1/4" thick pieces I had an idea of sandwiching one piece between the other two pieces. Reason being I took the middle piece of 1/4" insulation and covered it in a commercial grade aluminum foil that is like twice as thick as any aluminum foil you can find in stores. Thinking since its sandwiched between the other two ceramic blankets the foil will be protected from heat thus making it last. Its just like you can buy foiled backed insulation or foil backed foam panels this is meant to be reflective to heat. where the ceramic is more insulative, the foil will be more reflective. Reflective is more important when dealing with heat thats radiated.

The head space up in the top of the stove still looks to have plenty but I will have to watch to see if it causes any smoke spillage when I open the door to the stove.

 

[begreen]

For of these mods are you keeping good records on flue gas temps? I'm curious if they are affecting the flue gas temps.

 

[Augie]

For of these mods are you keeping good records on flue gas temps? I'm curious if they are affecting the flue gas temps.

I just did the top and sides with Insulating firebrick, quick, dirty, and it gives me a great performance boost. I think the rest is just eeking out the last little bit. Flue temps stayed the same, Im in secondary burn longer at lower air settings, so there is less volume of air going up the flue, but class A pipe is really good at holding that little bit of heat needed till it is at the top

 

[Huntindog1]

I should have taken some before and after flue temp readings but I didnt last year after doing the first mods.

I had the materials left over so I did it just to do it and see how the stove will perform.

I am thinking if the stove is a little hotter late in the burn cycle for a longer period of time my house should be a little warmer in the morning when I get up.

Augie, this is just like everything else in the design world its takes so much to eek out a little more performance that the manufacturers cant justify the cost of adding stuff to get out maybe 1% more. But that doesnt stop me from tinkering.

I think the biggest gains come from making sure a person has the best driest wood available. Determining what is the best size of the splits and being able to load the stove just right.