Stove tweaks

[EatenByLimestone]

All of our stoves were produced at a certain price point. Because of this, they may have specific areas that could have been improved upon with a little more time/money invested. Many of us also burn the same stoves.

What tweaks have you made that would help and could safely be duplicated by others with the same or similar stove?

Please follow the following format so we can quickly compare between owners of the same stove.

Stove make and model:

Specific problem(s) noticed and addressed:

What worked?

What didn't work why?

Any additional information that you think would be helpful to somebody buying your stove:
.
.
.
.
.
.
.
.
.
.
.
I guess I should go first.

Stove make and model: Century 240007

Specific problem(s) noticed and addressed: The main issue I found with my stove is all of the smoke is not forced over the secondaries. If the smoke is not forced to burn the stove is not pulling all of the heat available from the wood being burned. The problem area is in the back of the firebox where the Secondary Air is heated. The square tube has a loosely fitted firebrick on each side. The firebricks do not seal tightly letting smoke and flame escape on both sides.

What worked? The first year I burned the stove I noticed the issue and layed a few extra firebricks on top of the square tube and against the walls above the secondary burn chamber. The hope was to make the smoke track longer so it would decide to flow the proper way past the secondaries. I also wanted to keep more heat in the firebox. The idea worked fairly well, the brick over the tube allowed the air in the feed pipe to heat up faster. This allwed the secondaries to come in quicker. But I wasn't happy with the leaking around the edges.

This year I picked up some Kaowool (high temperature insulation) and stuffed it in the cracks and crevices around the brick. I also layed some on top of the firebrick in an effort to keep more heat in the firebox. It seems to be working. I no longer see flame being pulled into the cracks and crevices around the firebrick. I suppose I'll know for sure when I pull the singlewall down to clean it.

What didn’t work why? Nothing yet...


Any additional information that you think would be helpful to somebody buying your stove: Be careful with the kaowool. I've read it can release asbestos like particles when disturbed. Is probably best to wear some sort of particle mask when installing it. Maybe mineral or rock wool would be an alternative insulation?

Matt

 

[EatenByLimestone]

Stove make and model: Century 240007

Specific problem(s) noticed and addressed: Ash trap door does not seal completely letting fresh air in at an uncontrolled point.

What worked? When I clean out the ash I leave enough to pack in around the door sealing the cracks and crevices at the edge of the firebrick trap door.

What didn’t work why? I tried to clean around the edges of the door thinking the brick would sit better and seal. This didn't work because I could never get all the ash out of the way and even if I could the metal expanding and contracting would probably ruin the seal anyway. The brick is probably not cast perfectly square and flat either.

Any additional information that you think would be helpful to somebody buying your stove:


Matt

 

[LLigetfa]

On my first RSF Onyx, the butterfly was notched too large for the amount of draft my chimney generated. I had a tall stainless chimney going up the centre of the house. Had I known the draft would be so good, I would have put in a larger diameter chimney to slow down the flow and extract more heat on the way up.

The dealer suggested a butterfly change but that would have meant a major teardown. I reversed the third secondary air tube so that some of the air holes were blocked by firebrick. This reduced the amount of flames hitting the glass. I reduced the size of the primary air intake to reduce runaway.

On my second Onyx, I had a shorter chimney and less draft so I needed to enlarge the primary air vent to help burn down the coals that would build up.

On my first Onyx, I mounted the central blower to suck hot air from the top of the stove. On my second Onyx, I had the blower push cold air up from the bottom of the stove. This allowed me to mount a furnace filter inline.

 

[BrotherBart]

On the Englander 30-NC the two baffle boards aren't as wide as the space they fit in on top of the secondary burn tubes. This then leaves you either pushing them to one side leaving a opening front to back on one side at the top of the firebox similar to what you had with the Century or pushing them to each side leaving an opening between them. Either way gases are escaping up the flue unburned. Since I had a few new kiln elements laying around I cut one to length, put a steel rod through the center and laid it on one side to fill the space. Works like a champ. All gases have to make the trip to the front of the firebox and they get burned on the trip.

The second thing was the space all the way around the firebox between the secondary manifold and the top of the brick retainers. Since the sides of the stove body are insulated at the top by the manifolds and below by the firebrick the space between them ran consistently 100 or so degrees hotter then above it or below it. A recipe for warping in the long run as far as I am concerned. I just packed rockwool into the space around the two sides and the back the first season and it is still there and the stove body is a consistent temperature top to bottom.

Now if I just knew how to design that thermostatic primary air control...

 

[precaud]

Modifying a stove is dangerous and I would never consider doing it

 

[BrotherBart]

Modifying a stove is dangerous and I would never consider doing it

I think that precaud cuts all of the welds and rebuilds the stove the way he wants it. :lol:

 

[Ernienomoreoil]

On the Englander 30-NC the two baffle boards aren't as wide as the space they fit in on top of the secondary burn tubes. This then leaves you either pushing them to one side leaving a opening front to back on one side at the top of the firebox similar to what you had with the Century or pushing them to each side leaving an opening between them. Either way gases are escaping up the flue unburned. Since I had a few new kiln elements laying around I cut one to length, put a steel rod through the center and laid it on one side to fill the space. Works like a champ. All gases have to make the trip to the front of the firebox and they get burned on the trip.

The second thing was the space all the way around the firebox between the secondary manifold and the top of the brick retainers. Since the sides of the stove body are insulated at the top by the manifolds and below by the firebrick the space between them ran consistently 100 or so degrees hotter then above it or below it. A recipe for warping in the long run as far as I am concerned. I just packed rockwool into the space around the two sides and the back the first season and it is still there and the stove body is a consistent temperature top to bottom.

Now if I just knew how to design that thermostatic primary air control...

Hello BB I am getting my NC 30 this week, I was and still am concerned about the gap between the two baffle boards. Can I just cut a piece of a baffle board that I have extra and put that on the gap and seal any little gap with wood stove cement. Another idea I had was to put a ceramic refractory piece on top of the baffle boards.

 

[precaud]

Put a layer of 1/4" Kaowool (ceramic fiber blanket) on top of the baffle boards, cut it to cover the entire surface, and you'll be good. That's what many stove manufacturers have been doing, and it works.

 

[branchburner]

From my recent post on tweaking the stove:

Stove make and model: Harman Oakwood (cast iron downdraft-type)

Specific problem(s) noticed and addressed: The secondary combustion requires a well-developed fire with a deep coal bed in the back of the firebox. In winter this is no problem, but burning smaller/shorter fires in warmer months means not having sufficient coals to close the bypass damper and get secondary combustion in the rear chamber. I wanted to get cleaner, more efficient small fires.

What worked? I took two approaches. The first was to reduce the size of the firebox by adding six extra 2.5" firebricks against the side walls. I stacked up three bricks (on edge) making a new 2.5"x9”x13.5” wall on each side of my firebox. This shortened its width from 21” to 16” (meaning the max length of my wood is now 16"). With the walls now closed in, as the shorter splits begin to coal they can no longer fall away to the sides and spread out on the floor of the firebox. So the deeper coal bed is more easily acheived, and the bypass can be closed with a much smaller fire. I will remove the six bricks when real winter arrives, and go back to burning 21" splits.

The other approach was to add three bricks to the floor of the firebox. Because I have a grate and ashpan, the hot coals tend to break up and fall through the grate, rather than build up into the thick coal bed I need. So with a nice cushion of ash below them, I centered the three bricks just below the grate, pushed right to the back of the stove, so there is no longer any air space there. My coal bed formed more quickly, and lasted longer, with a solid firebox floor. It allows no way for the essential coal bed, as it burns and breaks up, to trickle down into the ashpan below. I think this is an important modification that I will leave through the winter

What didn’t work why? The other issue is that fires tend to burn very hot with the bypass open while trying to achieve the coal bed, due to ample uncontrolled secondary air. I have attempted some secondary air modification to slow the burn, but not really in a methodical way... yet.


Any additional information that you think would be helpful to somebody buying your stove: This stove is very draft sensitive, needs dry wood, and a bit tricky to get the hang of. It throws a lot of heat from the rear of the stove, where the secondary combustion occurs. The seconday combustion area tends to accumulate ash, so it needs occasional cleaning, and the combustion component is rather fragile. If anyone wants to PM me, I am happy to go into more detail.