The sign of a good draft which is important , but you 'cheated' adding air to the fire by opening the clean out . It probably just jumped up from the addition of more air. Try doing the same thing while blocking off the air for a moment with a piece of plate glass. Again , just a moment , glass will probably get hot.

How far does your chimney extend past your roof ? Short/obstructed chimneys can have drafting problems.

Check out one of Tmans sponsors Wildlife Control Supplies

This is close to what you need , would need measurements to get a proper fit.
https://www.wildlifecontrolsupplies.com/animal/BT1421K.html
They have dual flue caps in stock.

Good people , fast shipping and they sell traps too.

I'll certainly buy from them Cragar.

My chimney sits on/near the peak and extends probably 4' if I had to guess

That chimney sounds good , 4ft past the peak .

To install the cap , you will need a caulking gun and some 3/16 masonry bits. The cap comes with a tube of construction adhesive and some TapCons. Easy install , hardest part is drilling the holes for the TapCons. With a decent drill and good bits , it's not bad. I can do one in under 10 mins , so it's not like it's real difficult for someone doing it the first time. The top is held on with stainless wing nuts ( included ) for easy removal for cleaning.

Santa cLeaned it.

Posco Learn me something here. I've done around thirty, stone. I was taught by the old stone masons to tuck only at corners of liner to stone, at liner joints.
Are you saying yours are free of the masonry all the way?
How do you seal liner at the top from rain?
This stuff is easier to show than type for me lol.

I have at least one more to do in my time. I have big arse barnies hoarded for the first 16', then will likely go
smaller stone, "maybe" ledge rock.

That chimney is very clean. I have found using ACS accelerated creosote spry really works well.

Yes, as much as is possible. Clay liners don't hold up well with all of the expansion and contraction they go through, especially when you have them encased in mortar. Whether it's a chimney block or a brick shell, I always try to limit the amount of mortar that comes in contact with the liner. You know what happens to a liner when you hit it with a hammer. It shatters. They start out hard but become punky over time and disintegrate. Stone makes things much trickier.


Chimneys expand and contract like any other material will and just as much of that expansion is directed up as it is sideways. The liner is expanding at a different rate as it's taking the lions share of the heat as it moves up the chimney. Every cycle lifts and lowers the masonry mass sitting on top of the roof. Something has to give and it's usually the material setting on top of the roof. I isolate the top portion of the flue with sill sealer or even carboard where it comes in contact with the cap. You don't need much, just enough to provide a slip for the liner to move through without disturbing the cement cap or wash spread on top of the chimney. Once the cap hardens, use a utility knife to cut off flush with the cap and run a bead of silicone caulking around it. Most chimney top failures I've seen are directly linked to this.

First of all good dry wood is a must. I like to open my stove up every morning , get it good and hot This will probably send sparks up , the stove pipes and ignite any creosote. Done every day , in a good chimney , a small chimney fire is not a problem. . I have a stainless chimney, with a bottom cleanout . If you think there is a bit of creosote up near the top, shove a wad of news paper in the bottom and ignite it. The suction of the chimney , will take it up and ignite the creosote. , and clean it out. This is just my way of dealing with it. Might not suit everyone

If you do have a bad chimney fire and want to cool it down, Take a part cup of water and throw it into the woodstove, immediately shut the stove door. The small quantity of water will change to high volume of steam, and quench the flames. repeat if necessary. . old243

I want to second Cragar's recommendation of Chimfex. Buy 2 to be safe. My brother had a rip-roaring chimney fire one time that was truly threatening his house. He used one Chimfex and it went almost completely out, but then he threw in the second one and everything went out, just as the firetrucks were coming down the driveway.

I am very schitzy about our chimney and even clean it once during the winter, roof snow allowing. I also use a powdered "Creosote Beater" (or something like that,) weekly. I have never had any problems with creosote and sleep well at night.

Moosetrot

I sure appreciate the wealth of info on here. Thank you. I love wood heat dearly, and am driven with great earnest on no elbows, straight clean stovepipe.

Knowledge is power.

Creosote is the result of the cooling down of the gases going up a chimney. Many chimneys show some form of the black creosote flakes right at the opening where the warm gases cool down rapidly . I used to have a very old cast iron pot belly stove in my house I lived in for 35 years. It was so inefficient that half the heat went up the chimney and the chimney never need to be cleaned. Took handful after handful of wood to keep my house warm. After a few years of that old stove I got an air tight wood stove. Cut my wood consumption down by 2/3rds. Kept my house hot,... too hot sometimes. But the chimney wanted to build up creosote so I just ran a brush up it from the bottom once per week. A single pipe outside a residence or shed seems to have a lot of creosote problems. But a triple walled chimney (triple walled keeps the inside hot) chimney in those situations seems to work fairly good, or better. Even if you burned well seasoned dry wood and choke a stove off or have an uninsulated chimney you still will have some creosote build up. Just keep it clean and there should be no problem.

Wanted to add that under the advice of a fireman, I went to the local fire extinguisher place and got some of the powder they take out of the extinguishers when they recharge them. The firemen make "chimney bombs" out of the powder by placing it is various thicknesses of plastic bags...heavier will make it all the way to the bottom while the very light produce bags melt away very near to the top. When there is a good chimney fire they drop them from the top, extinguishing the fire.

Moosetrot

Moosetrot, When I was on our VFD we did just the thing you describe. Also if there is still a draft from the bottom ( or stove) in a chimney fire, we would take a small dry powder fire ext and shoot short blasts of powder into the chimney or stove. The draft carried the powder up and helped suppress the chimney fire. I have been on chimney fire calls where you swear a jet engine is inside your burning chimney. Fire can be roaring out the top like a big torch.... several feet high. On the old houses where it was just a mortared brick sq chimney if there was some joints missing mortar, that was where some burning creosote would or could leak out and start any nearby wood on fire. Also never, never use cold water on a chimney fire, as it could crack your liner or bricks.

That sounds like the situation my brother was in! Old chimney in an old farmhouse. He got really lucky.

Moosetrot

I salvaged the brick for this hearth from an old homestead that burned down in a fire. The house had a great deal of sentimental value to me so I approached the owner asking if I could have the brick. The chimney was the only thing left standing so I put a rope on it and gave it a tug using my truck. Most of the brick turned to dust when they hit the ground. I never thought about the brick being quenched with cold water. Salvaged every brick I could and had just barely enough to do the job. Sorry about the glare.

my grandpa was the go too guy for fancy chimneys and big huge elaborate fire places in south east Wisconsin till he retired in about 2000 after 45 years.


when I asked him about how I should build a chimney when I was installing a wood stove a couple years after he retired.
he asked what do I have in my house? you have 2 chimneys the one to the basement that is masonry but only the hot water heater goes up anymore and the one in the living room with the wood stove that is metal and goes strait up through the roof.
yes, he said double or triple wall insulated SS that exceeds code now. then heat your house clean once a year and almost never worry about the chimney again. get a good four feet above the roof-line as strait us as you can get stove to cap.

I did just that, the EPA stove I use my chimney looks like the one pictured after 2 years of burning I clean usually every year just to be sure but I get a half cup of dry powder from 22 feet of chimney , I clean from the bottom by removing the telescoping pipe between the stove and ceiling thimble.

I have double wall stainless insulated pipe from the top of my Vermont Castings stove, through the attic and extending 4 ft. above my roof, a run of about 15 feet. My theory is that the hotter I can keep the gases till they go out the top, the less chance of collection of creosote in the pipe. With using the Creosote buster powder weekly, when I brush my chimney from the top I only get a couple cups of dry powder per year.

Some folks say I lose the available heat from the top of the stove to the ceiling by not using single wall, but reducing the risk of a chimney fire is more important to me than the heat that I may lose.

Moosetrot

From what I learned burning wood inside, I would recommend burning well seasoned wood. If you have a two story house I would also recommend burning a little bit hotter. I noticed, on our two story house, burning seasoned wood it would build up 6-8' from the top. Not much, but enough to clean around Christmas time. Burning less seasoned wood and/or dampering it down too much (even with seasoned woo) would cause it to build up about 10' or so from the top. There is a point in your chimney that the gasses cool down, that is where you will have your problem.

If you are lucky enough to have a clean out port 3-4' off the ground you can run a brush up it to keep it from plugging. I could tell when loading the stove when it was plugging.

This is with a stove that is many years old. If you have a new one I can not help with that. Burn hot and burn seasoned. Or do like I did and get a outdoor burner. I throw what ever in it. As long as it is 5' or less and I can put it in it goes in. Cut way down on the splitting and cutting. Love it.

the compromise on max heat vs clean chimney is burn the first fire of every day with the air intake open , burning hot this will get you a nice bed of coals going and dry out the chimney sending more heat up the chimney then you can reduced the air and slow the fire making longer time before loading the stove.

a good hot chimney every day dries the creosote and it flakes off dropping into the stove