Wood stove insert refurbish and install

[Mother Fussbudget]

Project: 
Refurbish, and retrofit a cast iron wood stove fireplace insert into a 70 yr old masonry wood burning fireplace. 

Step 1:
Removed existing fireplace doors - brushed brass & glass with a steel mesh 'curtain', and listed for sale on CL.
The unit is in good shape, and came out easily after loosening the adjustable attachment brackets, and slicing away some caulk.
Cleaned up the fireplace - will eventually purchase a drill attachment chimney sweeper tool ($50) to clean the masonry chimney.

Step 2:
I bought a ~30 year old "Country" brand wood stove insert (made in Auburn, WA) from CraigsList for $250. A comparable 'new' stove costs ~$1.5K. 
It came with:
 * soot / grime blackened glass doors. Cleaned with vinegar, steel wool & elbow grease.
 * broken electrical blower fan. Re-connected a wire, and it works. Spot paint with high-temp black paint, and good to go.
 * 15-feet of 8" steel flex chimney liner (plan is to clean this up and re-sell on CL).
 * 15 (of 19) cracked/broken fire bricks in the liner

Loading / unloading / moving the stove was hard - VERY heavy.  Removing the broken fire bricks at the seller's house wasn't practical. 
Moved the stove with the bricks in place - won't ever try THAT again...  But having three available young men (me + 2 sons) did the trick.

Step 3:
Removed all old fire bricks, and shop-vac'd the hell out of the stove.
Purchased 19 new replacement bricks ($50) at the local hardware store.
(New fire bricks will be the LAST thing to go back in.)

Step 4:
Prepare the fireplace & chimney for the insert.
This is the biggest job.  The attached picture shows the plan:
 * Purchase new 6" steel flex liner + insulation (chimney is too small for the 8" pipe that came with the stove).
 * Purchase steel chimney cap & spark arrestor.
 * Purchase catalytic combustor + 6" x 24" steel liner to form "catalytic damper" (will need to find a friend with a welder to help here)
[trying to replicate this - for half the $205 don't need a fancypants handle - this will be enclosed behind a wall]

 * Cement, and high-temp caulk things together to assure no air leaks.
 * Cut away firebox steel & masonry to make room for 6" steel flex liner(i.e. 'retrofit' - diagram attached).
 * Trim 1" of tile on either side of fireplace opening to clear room for insert.
 * Trim tile + masonry above stove insert to allow attachment of chimney liner / flue assembly to stove (with stove cement).
   NOTE: steel stove surround (included) will cover the trimmed fireplace face tiles, and front cutout for flue attachment.
 * Purchase chimney sweep drill attachment, and clean creosote from the chimney liner. (also clean out the 8" flex pipe prior to sale)

Skil saw + masonry blade, and angle grinder + steel cutting wheel, earplugs, respirator and generous use of plastic masking & tape are the main tools. 
It will be loud & dirty work, but steel & brick doesn't cut itself.

Step 5:
Manufacture an external handle to engage / disengage catalytic combustor ring 'damper' within the flue.
Assemble flue liner components, making sure to insulate liner, and seal all connections with high temp caulk or cement.

Step 6:
Slide stove insert into position.
Attach flue assembly, and allow 24 hours for connection cement/caulk to cure.
Route external 'damper' handle.
Install new fire bricks in stove insert. 
Perform test-burn / check for smoke leaks & clean roof exhaust.

Step 7:
Stuff insulation in any front cracks, caulk, and install steel face plates.
Install repainted blower.
Start chopping wood for next winter.

Comments?  Ideas?  Face punches?

[lthenderson]

Looks great. I chickened out and had my wood burning insert installed by the place where I bought it. After seeing them do it, I realized that there wasn't really anything too technical to it so I would probably attempt it the next go around if I ever need it.

I love having a wood burning insert. I wouldn't trade it for the gas insert that we tore out even if you gave me a pile of money to boot.

[Gone Fishing]

I don't think a drill driven chimney brush is necessary.  I run a basic brush on fiberglass rods up and down my chimney 2x and really don't get much on the second pass.  No need to be spotless, just need to knock of the bulk of the creosote.   A tight brush applies quite a bit of lateral scrubbing pressure.

I know you already have, but I wouldn't spend too much time cleaning glass either.  As soon as you light your first fire, it will probably soot up again.  A good hot fire will get it about as clean as it will get.  Any abrasion on the glass might create a weak spot that could lead to breakage down the road, so I do my best to avoid touching it with anything metallic.

Your cat design sounds interesting, but might not yield much heat if it buried behind the insert if the blower air is not circulating around it. Couldn't quite tell from your description if it was or not. 

Hope it works out well.  Wood heat is awesome!

   

[Mother Fussbudget]

Good feedback on the brush - I'll price out some manual brushes.

As for the catalytic combustor - the main reason for it is to clean the smoke plume so I'm "not that guy" in the neighborhood with the smoky fire.

I found thisdamper assembly, and think for $20 it might be a good exercise to grind / cut away the damper plate to open a hole for the catalytic ceramic disk.  With this, and the $80 catalytic combustor disk (Amazon).  I could make TWO for the price of the $204 finished assembly, and LEARN something in the process.  So I'm going the DIY route on this part.

[Gone Fishing]

Good feedback on the brush - I'll price out some manual brushes.

As for the catalytic combustor - the main reason for it is to clean the smoke plume so I'm "not that guy" in the neighborhood with the smoky fire.

I found thisdamper assembly, and think for $20 it might be a good exercise to grind / cut away the damper plate to open a hole for the catalytic ceramic disk.  With this, and the $80 catalytic combustor disk (Amazon).  I could make TWO for the price of the $204 finished assembly, and LEARN something in the process.  So I'm going the DIY route on this part.

Cool.  A few more thoughts:  If you burn well seasoned hard wood (12+ months under cover) you should get very little smoke after the fire gets going.  You can also experiment with top down fire building techniques to further reduce smoke during start-up.  Those cats can get hot, very hot, cherry red hot, so make sure the materials you use for the damper and the area around the cat are up to the task over the long haul and readily inspectable. 

Just noticed your location.  Any legal restrictions?

[Gone Fishing]

Found this thread on add on cats, http://www.hearth.com/talk/threads/add-on-catalytic-stove-damper.27687/ wouldn't hurt to search for more.  My stove and pipe setup is actually a perfect candidate for such device (which led me to the search), but I would need some compelling reviews in order to take the chance.

[jacksonvasey]

I've heard the old insert stoves are terrible at circulating heat around, so I'll be interested to see what your experience is once you're up and burning.  Does this one have a blower?  If so you might want to test that out a bit, and see if it needs cleaning/lubrication.

I replaced my really bad vermont castings insert last year with a new napoleon insert, and the new one cranks out the heat.  The vc couldn't heat up my living room, let alone my whole house.

[Mother Fussbudget]

I've heard the old insert stoves are terrible at circulating heat around, so I'll be interested to see what your experience is once you're up and burning.  Does this one have a blower?  If so you might want to test that out a bit, and see if it needs cleaning/lubrication.

I replaced my really bad vermont castings insert last year with a new napoleon insert, and the new one cranks out the heat.  The vc couldn't heat up my living room, let alone my whole house.

The stove came with a blower - it looks like a Lennox Country Collection blower model H7912 - replacements on-line range from $300-to-$450.  It did *NOT* blow at all when I got it - the wires were disconnected.  But... the fan barely worked with the switch/rheostat set to full, and sounded strained.  I took a chance, removed the switch from the circuit, and when the fan has direct 110v AC current it blows like a hurricane without much noise.  So, I found a replacement switch for $13 on ebay.

I've modified the install somewhat, going with an adjustable wood stove offset adapter.  I'll connect it directly to the stove, and with only  3-inches of height, it routes the exhaust 9-inches back - making for a straight shot vertical rise for the chimney.  I'll put the 8" to 6" reducer on the offset adapter, the catalytic combustor above that, and into the insulated flex liner.

I've been learning more about this than I want, and will update later. 

One thing to warn about:  Great Stuff Fireblock foam is only rated to 230-degrees, so *NOT* appropriate to a fireplace install.  I'm planning to use fire brick mortar in-a-caulk-tube for chimney liner connections, and thin fiberglass bats to fill the cracks between the fireplace and the front of the stove insert.

[Mother Fussbudget]

UPDATE:  I completed the wood stove conversion, and after a failed run in early October, have it adjusted to where the flue gases are less smokey AND the stove pumps out the heat.

In the original diagram, I show a gradual slope of the flexible chimney liner from the top of the stove to the terra-cotta liner in the brick chimney.  This did not work because at the top of the stove, there is a steel support holding up the bricks in the front of the fireplace.  With only 6" of clearance, I had to go with an 8" chimney offset adapter that offsets the main exhaust 9-inches behind the original exhaust port on the stove.  It's 4" tall.  Inside this steel box, I put the catalytic combustor on a sliding steel plate, and 1/2" steel pipes with holes drilled to allow for a separate air intake for the combustor.

Now I need to sort out the squirrel fans in the blower.  When at top speed, the fins in the fan blades resonate giving out a screeching noise that's unbearable.  Need to find some way to either fuse / support the fins mid-span of the blades, or come up with a quieter fan solution.  Currently using an old house fan blowing AWAY from the stove.

[Gone Fishing]

Glad it is coming together.  I am burning wood as we type...

[merle1984]

That stove set up will create a lot of creosote depending on how much you burn. The brush that you are using might work although, the vacuum that you are using to clean up the debris will not. I paid $3,200 for each of the vacuums that I use to sweep. Regular shop vacs wont work.
Customers ask every time I sweep which is the best wood to burn? Just simply dry wood, build a rack that is a foot off the ground and is completely covered, seasoned for at least 6 months.

[Fishindude]

Question.   I've always had wood stoves, so not real familiar with an insert installation.  How do they tie the flue outlet on top of insert to the house flue in an airtight sealed manner so there are no gaps?   In many cases the house flue might be square while insert outlet is round.   There is also very limited access space to reach in and do any work, once the insert is in place.

[Spork]

That stove set up will create a lot of creosote depending on how much you burn. The brush that you are using might work although, the vacuum that you are using to clean up the debris will not. I paid $3,200 for each of the vacuums that I use to sweep. Regular shop vacs wont work.
Customers ask every time I sweep which is the best wood to burn? Just simply dry wood, build a rack that is a foot off the ground and is completely covered, seasoned for at least 6 months.

I vac my wood stove after sweeping with a regular old house vacuum with a hepa filter.  I've done it 2-3 times a year for the last 5 years with zero problems.  Why would you need a high dollar vacuum?  Just due to the nature of how fine the ash/creosote is?

[lthenderson]

Question.   I've always had wood stoves, so not real familiar with an insert installation.  How do they tie the flue outlet on top of insert to the house flue in an airtight sealed manner so there are no gaps?   In many cases the house flue might be square while insert outlet is round.   There is also very limited access space to reach in and do any work, once the insert is in place.

In my case, they ran flexible round pipe up through the original house flue. I don't think any of the inserts would connect to a square one. For the air tight seal, they use a high temperature adhesive of some sort (and clamps to hold the flexible pipe to the flue outlet on the insert) that had to dry for a couple days before your first fire.

[Mother Fussbudget]

This is what I did - ran a 6" x 15ft. flexible steel flue insert through the existing square brick [terra-cotta] chimney liner. 
It was a tight fit.  I had to deform the top 10-feet of the flexible flue liner to make it fit (light stomping does wonders). Then insulated the lower 4 feet (there was no room for insulation inside the terra-cotta liner).  To seal the flue liner to the off-set box, I used foil tape and duct mastic to seal the joints.  I used high-temperature concrete sealer (caulk) to seal the rain cap to the terra-cotta liner, and to seal the stove insert to the steel offset box.

[merle1984]

Question.   I've always had wood stoves, so not real familiar with an insert installation.  How do they tie the flue outlet on top of insert to the house flue in an airtight sealed manner so there are no gaps?   In many cases the house flue might be square while insert outlet is round.   There is also very limited access space to reach in and do any work, once the insert is in place.

The inserts will be attached to a stainless steel pipe, eliminating the use of the original flue tiles. Late 90's I think Duravent became popular, although it was expensive. This was replaced by flex piping which is more commonly used today. A single ranch pipe replacement is minimum $3k, materials are about $200 from wholesalers, take a full day to do the install. As far as the insert itself, you have to have a "insert puller" which will carry the weight and move the insert 3 feet away from the fireplace. It is a huge pain, I haven't ever pulled a light insert. So I charge minimum $300.00 for this. Hope this helps.

[merle1984]

That stove set up will create a lot of creosote depending on how much you burn. The brush that you are using might work although, the vacuum that you are using to clean up the debris will not. I paid $3,200 for each of the vacuums that I use to sweep. Regular shop vacs wont work.
Customers ask every time I sweep which is the best wood to burn? Just simply dry wood, build a rack that is a foot off the ground and is completely covered, seasoned for at least 6 months.

I vac my wood stove after sweeping with a regular old house vacuum with a hepa filter.  I've done it 2-3 times a year for the last 5 years with zero problems.  Why would you need a high dollar vacuum?  Just due to the nature of how fine the ash/creosote is?

I apologize for the delayed response. The price is not only for the quality of the filter but for the structure i.e. seal, of the vacuum. I sweep chimneys as a side business which requires industrial/commercial grade equipment. I rely on EPA data opposed to the underappreciated home depot employees opinion. I do not consider all HEPA filters equal in mass production. Creosote is a B-2 air toxin, so is Propane Sultone, and Rockwool.

[Mother Fussbudget]

Thanks merle1984 for your feedback. 

Quick update:  in regular use, the squirrel cage fans in the blower assembly (Lennox Country Collection blower model H7912) would 'scream' due to sympathetic vibration in the long-fan-blades when running at high speed.  It might be fixable by securing something mid-blade to keep them from vibrating (an epoxy 'brace' that encases the blades, or similar)... BUT... it seems like a lot of work, so instead I'm using an old house fan, and built a makeshift 'funnel' / cowling that directs the round fan output into the low rectangular blower intake on the stove. 

[NOTE:  The blower air input for my stove insert are mis-labeled on the drawings (attached earlier) - the input is at the BOTTOM FRONT of the insert, and the warm air output comes thru the sides and top of the stove.  But stove owners probably knew that...]

Also... I got my December gas bill, and realized a 52% savings over last year from burning wood.  Savings:  $85