NC 30 baffle boards

No this isn't about obtaining new ones. But rather reducing the draft rate at perhaps a bit richer oxygen rate.
This morning, to see what effect would transpire, I replaced my baffle boards with some other material that is 2500 degree rated and 1" thick. This material is used in the construction of heat treat furnaces and kilns. I do not remember its brand name as I had gotten it some 7 years ago to replace baffle in another stove since retired. Now the 30 boards are apx 1/2' thick vs this at 1", there is room, just have to pull 1st and 2nd tubes to install. Made the baffle plates a bit bigger than the originals to account for the infamous 1/4" gap. and about a 1/2" longer as well so they overlap tube one. Course being 1" thick it will restrict exhaust some but with 50 deg temps outside I can't really get a idea total effect ( another bit of exhaust restriction). There was a marked difference in the onset of secondary combustion( earlier) and it does seem to last much longer than with my oem boards. This was from a cold start and no ash bed. Due to the temps it was a bit more difficult to get things rolling.
My oem boards are fine I just had a hankering to try this and already had the material at hand. This 50deg stuff will be out of here by tomorrow and back 20-30 something range. That will make a difference in the draft rate. Flue is a bit shy of 15' double wall inside, triple from transition on up. stay tuned. Oh and happy Thanksgiving to all. ( note Rolaids are in Isle 4) Chris

 

chris , been contemplating the same mod.
I wondered about the exhaust restriction though. The link I have Ceramic Fiber Board is a bit pricey, but so are the stock baffles.
Maybe it's different with the thicker boards, but I only pull the front tube, and have no problem getting them out.
How are you measuring total flue height? Manual says to go from hearth to tippy top of the cap.
I could order new stock baffles, then just add those on top of the originals too.

 

Back when I purchased this material a 4x4 ft sheet was about $50. Because this is 1" thick you need to drop the second tube material is not bendable just like the oem boards. The material was purchased from a company that builds and repairs kilns and heat treat furnaces. It is similar but not the same as OEM boards as the fibers are longer. Maybe not quite as dense. Indications so far are great much faster firing of secondaries and a much longer run on those - more control with the air knob out front ( note mine never did much until it was about 3/4 of its travel pushed in. Now it has an effect from about 1/2" in front of ash lip. Flue height - top of stove to ceiling about 5ft - transition unit about 1.5ft 4 ft tripple wall gets me out the roof with enough room for the rain skirt then another 4ft triple wall and then the cap ( 6-8" worth there but it really does nothing as far as being a flue extension) so roughly 14ft flue. I am 1/2 way down a hill with 40-80ft trees behind me. I do get external down draft days although that has never been a problem with the 30 ( now that darn hot blast furnace in the basement is another "xyz" story - haven't used it since I got the 30). My fuel is 4 year old css mixed hard woods, mostly hickory and Honey locust this year. So far I do not see any problem with the reduced draft on my unit. But every install is different. 2 sets of oem boards will still be a bit shy of 1" Keep meaning to stick the meter into a fresh face likely 12-18% on the HF meter. Still in the high 30's here at present. Got about an hour + run on 4 splits apx 2x2" just into coaling stage on those as of now(from a cold start again). Currently 210 deg IF reading on stove top at step with the big blower on full. Will be putting a full load in this morning as I have to go to shop to keep all the bill collectors happy. Next several days of forecast has my area sitting at apx mid 30's avg with rain /sleet /snow off and on. Makes for dicey driving conditions- Black ice patches where the wind can blow across the road surface and overpasses.

 

Sounds as if putting in those thicker boards is acting as sort of a full time exhaust damper. My old stove ran longer when I used the pipe damper.
Have you noticed any buildup at the cap?
Yeah, I thought the thickness might hinder getting it in with only one tube pulled.
I see about the same with the air control, and would be nice to see better control...sooner. Reaching under the lip is sometimes a little dicey.
I've gotten secondaries up to about 2 hours at times.
Always looking to improve and extend burn time. I never (so far) run the blower more than about 25%. That's a lot of air with the AC30.
You've really got me thinking on this.....again.

 

addendum: fuel reads 13-15% fresh face bandsaw cut, meter across the grain- hickory and Honey Locust. Harbor freight meter for what its worth.
Have not been on roof since cleaning 2 weeks ago- style of cap I have never clogs as there is no screen it is concentric rings ( Selkirk) Never has been much of a build up in it. Flue cleaning after a year and a 1/2 produced maybe 2 cups of fine black soot, I had more gray ash built up inside and on top of oem boadrs than that ( over 1/2" deep on boards)

 

Update: with the 1" thick boards up top fire box retains higher heat longer- so it seems that i am achieving a more complete combustion and less coal build up. It also seems easier to burn down a larger coal bed than before to get down to a modest coal bed for a reload.( raked up coals this morning about 1/2 the fire box full-load was 3 4x4 damp splits and a bunch of odds and ends that were kinda wet- trimings from ends of too long pieces) that was put in about 10:30 last night Raked forward at 3am and a pair of ECCO block set on top-1.5hrs later good for reload.) I gave the 30 a hard time yesterday as I loaded Siberian Elm that has been thoroughly drenched and was also lightly snow covered ( ya I knocked that off) I also sectioned some of this to see how far the wet weather had penetrated in some cases up to 2" deep on a 6x6 - load at 5am got home around 9:30 pm perfect reload coal bed. Outside temps 30-40 mild for this time of year. still was 72 inside.

 

So, I ordered the baffle material from here.....Ceramic Fiber Board
I got the 1/2" stuff. Cheaper than the stock boards. Hope it does well.
I'll put this on top of the originals to begin with, and go from there.
Should be here next Wednesday.
Very curious to see how this works and if I see similar results with burn times, etc.

 

I ordered the same boards and install them this summer. After a couple burns in the stove they seem to work well. I cut them to be tighter without the gap and they work awesome.

 

I don't remember who, but someone posted that link a while back, so I bookmarked it for future reference.
The future is now.

 

Subscribing. Got the "little brother" of the 30 NC.........................curious here!!

 

I did the same thing!

My boss has the NC-13 in his cabin in northern NH. There is enough of the board to make three baffles. In the next couple of weeks we are going up to install on his NC-13 as his fiber board has a hole in it.

 

Wouldn't mind hearing the results when y'all replace it.

 

Is the new baffle board longer and comes out furthrr to the door/glass? Choking down draft a bit? Wouldnt mind tryinf this as i can watch flames being pulled up over the current baffle. I have 25 ft of 6" liker thay i think needs choked down a bit
1/2 way inside a fireplace cant do a conventional damper

 

Yes I made the new boards about an inch ( give or take) longer ( note they are 1" thick as well) as well as wider to eliminate the infamous gap. I am getting a better burn rate and more heat off the coaling stage ( at least it seems that way) but it has been relatively warm here - nothing has froze down solid yet and more rain predicted for upcoming weekend-That may change of course but temps all week predicted to be above freezing 24/7 for the most part.

 

Got the board today.
Very easy to cut and seems very similar/same as original.
No fire yet.

 

Doubled up my boards this past weekend too PD, I'm thinking its working pretty gooder, secondaries are definitely firing off sooner and I think I am seeing higher STT, but I added the convection deck at the same time so it's hard to tell.

 

Had a fire with some small Poplar splits. 42 outside, and no undue smoke when I opened the door. More fires will be needed to see what's up with this.
DaveGunter , where'd you get your board material?
There'll be some waste with the stuff I got, but I'll get 3 boards out of it.

 

Lets see some pics of those convection decks with details on materials!