Home made refractory package for Resolute

[Brian VT]

I bought my stove used last year. I went through it and the secondary burn box was in tough shape but I ran it through the winter.
Since I found out that a replacement is $225 I've been threatening to try to make one from Kaowool board.
I made it tonight. It cost $80 for the Kaowool at a plumbing supply store. I could probably have spent less if it hadn't been spur-of-the-moment
and I had a better idea of sizes, etc. I bought a piece of 1"x20"x20" and 1/2"x18"x36".
Anyway, I had heard somewhere here that the box had baffles in it. Mine didn't. It turns out mine had crumbled away before I got it.
I looked at a new box today and saw the baffles. Between what I saw and the measurements I could get off my old box I made the box shown below.
I assembled it with furnace cement and 4d finish nails.
I don't know how well it will function or last. I'll probably button it all up and have my first burn tomorrow.
I'll post here when I have some results throughout the heating season. If it all works out I may make drawings for those that might want them.

 

[Diabel]

Good for you to try something outside the "circle" I hope it works!

My everburn chamber is crumbling & I believe this will be its last season...I wish I could make something out of that stuff for my stove...

 

[branchburner]

Nice. Maybe I'll try that in a few years when mine is toasted.

Any idea if the stuff you used is similar in durability to the VC material, or better, or worse? I recall a thread a while back saying if VC spent a few bucks upgrading the ceramic fiber board just a bit that these boxes could have a much longer lifespan.

 

[jdinspector]

Nice job Brian. I think that you and I had posted on this subject before when someone inquired about installing one of these. I got tired of buying a new box on average every other year or so. I was as careful as can be with mine, and it just fell apart. I considered trying to do what you've done. Yay for you. I hope it works.

One thing I see... The bottom of the refractory box from VC has small holes in it. When the box was new (and clean) I could see flame running into these holes (about 10 holes across the bottom). I assume they were to help with secondary burn? Not sure if this will cause any issues with your box. Stay close to it and monitor the temps. Good luck!

 

[burr]

Have you seen an existing baffle in this stove ? Is it installed in position in the stove in your last picture ? There has got to be some kinda protection (and I mean SS plate or equal) against ANY abrasive type contact with kaowool and kaowool board - it has no defense against a log and will not last. This particular board appears to be maybe 4pcf or 6pcf 1600 or 1800 board and when working with it, you can tell of its' strength. It gets weaker after fired.

Looking at the last picture, is this a bracket for bolting (right side, see arrows, hopefully one on left side too) for such a protecting plate ? I'll be honest with you that I'm just posing a WAG; I have very little knowledge of baffles and new stove technology, but I have a pretty good hold on Kaowool products.

 

[jdinspector]

Have no fear Burr. He is just showing the refractory box in place. A cement arch brick goes in front of the box. Problem is, the arch brick also deteriorates after time. There is one unprotected area on the box in it's final place. The bottom has an exposed edge that used to fall apart as I raked ashes towards the front of the stove. That's where the little holes I described above are located.

Ughhh, this brings back bad memories.

 

[jdinspector]

Now that I look at Brian's photos, I see that he does have the little holes down there. Nice fab job. I hope it works.

 

[branchburner]

Burr, after just one season the board in my stove is already brittle and degraded. It seems there is a very narrow window between the temps you need to get secondary combustion and the temps at which these boards get toasted. Is there any commercial product, not super expensive or difficult to obtain, that would withstand many years in a stove that runs on the hot side?

 

[Brian VT]

I did drill the holes. You can kinda see them in the last pic. There's 10 across the bottom and 5 above that, through the back.

 

[Brian VT]

This particular board appears to be maybe 4pcf or 6pcf 1600 or 1800 board and when working with it, you can tell of its' strength. It gets weaker after fired...I have a pretty good hold on Kaowool products.

The only part that is exposed is the bottom front edge. Wood can't really get to it, but someone raking coals can.
That said, how well do you think this might work ? The sales guy said they make oil burner chambers out of it and often the flame is hitting the board.
I realize wood smoke is of a different composition but the temps. shouldn't get any higher than with an oil burner ? (I forget the temp. of secondary combustion.)
I'll be trying it anyway, but I wonder if you have any prediction on it's performance.

 

[burr]

Burr, after just one season the board in my stove is already brittle and degraded. It seems there is a very narrow window between the temps you need to get secondary combustion and the temps at which these boards get toasted. Is there any commercial product, not super expensive or difficult to obtain, that would withstand many years in a stove that runs on the hot side?

Fired product appears as brittle and degraded actually, use is not diminished. Initial firing of 'green' will produce expected shrinkages, further use will produce little more. Wood heat temperature is barely applicable to kaowool products, especially including flue wrap.

Board products have temp ranges to ~2850F, maybe more today.

All refractory products are very expensive due to manufacture expense. These products (ceramic fiber) are basically made by MELTING SILICA (sand), just to begin the process. Refractory products are not produced to sell at HD.

 

[burr]

This particular board appears to be maybe 4pcf or 6pcf 1600 or 1800 board and when working with it, you can tell of its' strength. It gets weaker after fired...I have a pretty good hold on Kaowool products.

The only part that is exposed is the bottom front edge. Wood can't really get to it, but someone raking coals can.
That said, how well do you think this might work ? The sales guy said they make oil burner chambers out of it and often the flame is hitting the board.
I realize wood smoke is of a different composition but the temps. shouldn't get any higher than with an oil burner ? (I forget the temp. of secondary combustion.)
I'll be trying it anyway, but I wonder if you have any prediction on it's performance.

Kaowool is efficient and effective on walls, roof, some burners, any place that will not have physical contact with an object, whether it is a log split thrown into a stove or a slab of steel in a roller hearth furnace. Hard refractory must be used in this abrasive (contact, abusive) condition.

As long as it is not physically abused, these temps should not affect the board. Keep the rake off it. Now, using 4d finishing nails, I don't know. Some grades of SS pins are industry accepted. Refractory cement is also a weak point. It is way stronger than fiber and this board is going to want to move (shrink) a little, maybe tearing at the mortar joint. A shape of this type would probably be produced as one piece in a vacuum formed process.

 

[Brian VT]

Refractory cement is also a weak point. It is way stronger than fiber and this board is going to want to move (shrink) a little, maybe tearing at the mortar joint. A shape of this type would probably be produced as one piece in a vacuum formed process.

I used the nails thinking I just needed to pin it together until the cement dried. I hadn't accounted for the board shrinking and I appreciate your info. on that.
The OEM boxes are, apparently, formed as one piece.
I wonder if I should relieve the cement joints before firing and also replace the pins with sheetrock screws ? Your opinion ?
Would high-temp. silicone be appropriate for the joints or will it also fight the contraction of the board too much ?

 

[jdinspector]

I agree that this stuff won't be affected by a little degradation, but the baffle literally falls apart. Especially, when yearly (or more often) cleaning is done. I remember the entire side of it falling apart when I took the arch brick off. The interior baffles that Brian fabricated were completely gone after one season. I think the combo of heat and vibration from logs and cleaning just allowed them to deteriorate. They fell apart bit by bit and I'm sure I scooped them into the ash pan when I was emptying I like Brian's fab job and am interested in how it works. My old Resolute stove is still sitting in my garage. I am going to give it/trade it to a friend for use at his cabin. If he can save $$ by making one of these rather than purchasing it, I'm sure he'd be interested.

Keep us posted Brian.

 

[dougand3]

Great job, Brian! I will try this on my model 0041.

 

[Brian VT]

I didn't know the 0041 had one. I thought they were pre-EPA.
My parents got one last year and they love it. I should go down there (MA) and check it's condition.

 

[burr]

If this application is 24/7, or cyclic, one years use is not terrible. Like I said above, refractory products are not cheap and are usually designed and developed for industry, not living room stoves.

You've got to remember / realize that the best insulation is air, right ? This application is being used where hardbrick are also used, meaning that a product that is 4 or 6 or 8 or 10 or 12 pcf (density of product - 4 or 6 pounds per cubic foot) is up against a product that is 120-140 or more pcf. It is 4-6 pcf because it has more air than dirt (kaolin, alumina, ect). Continious cyclic use is tough on the lighter refractories.

I don't know what you mean by cleaning but fiber needs to be left alone after installation - to move it , touch it, or clean it is not advisable for the product life AND to add, airborn fibers are not healthy.

 

[dougand3]

I didn't know the 0041 had one. I thought they were pre-EPA.
My parents got one last year and they love it. I should go down there (MA) and check it's condition.

The 0041 was made 1988 - 1994. It has a refractory box that looks real similar to the 2490. I'd love a copy of your dimensions.
The only hi-temp silicone i've seen is rated to 600F - do you know of higher ones?

 

[Brian VT]

The only hi-temp silicone i've seen is rated to 600F - do you know of higher ones?

You're right. For some reason I thought mine was 1300F. Disregard that idea.
My only real concern with this project is that a baffle might degrade enough to fall down but be intact enough to block the opening.
I think the odds of that happening are very slim, but I'll be keeping a vigilant eye for anything like that.
I suspect they'll just come down in crumbs like the OEM one. lol.
If this lasts 2 seasons it will be worth it. If it only lasts for one then the OEM is probably worth the $.

 

[Brian VT]

Here's the final product before it goes in. Let's hope for the best.
You can see the upper and lower air holes a bit better in this pic. The lower air holes are cut/stepped back into the box, like the OEM.
The bottom front got shaved for the upslope of the cast iron floor it sits on.
I don't know if I'll fire it today. It's almost 60F. Plus, I plan to head back into my tree stand later in hopes of putting some deer meat in the freezer.

 

[branchburner]

If this application is 24/7, or cyclic, one years use is not terrible. Like I said above, refractory products are not cheap and are usually designed and developed for industry, not living room stoves.

You've got to remember / realize that the best insulation is air, right ? This application is being used where hardbrick are also used, meaning that a product that is 4 or 6 or 8 or 10 or 12 pcf (density of product - 4 or 6 pounds per cubic foot) is up against a product that is 120-140 or more pcf. It is 4-6 pcf because it has more air than dirt (kaolin, alumina, ect). Continious cyclic use is tough on the lighter refractories.

I don't know what you mean by cleaning but fiber needs to be left alone after installation - to move it , touch it, or clean it is not advisable for the product life AND to add, airborn fibers are not healthy.

One year is terrible if you are talking about replacing a $200-300 piece every year or three. The trouble with using this material as a secondary combustion chamber is that fine ash tends to build up within it. If you do not clean it periodically the air flow is eventually impeded. But it does seem to become crumbly even before it has been handled or cleaned, maybe because of heat cycles or vibration?

Constant cyclic use is exactly what this piece is subjected to: cold stove, hot stove, repeat. Even if the stove isn't going completely cold and you shoot for long continuous burns, you will have temp variations in re-fueling cycles, cooling down at the end of coaling, then reloading the firebox, etc.

In addition to temp change, there is also often a lot of vibration when the secondary burn kicks in on a real hot fire. I'm just wondering if a better version of the same basic material is possible. Is there going to be a big difference in lifespan if the board is 4-6 pcf vs. 10-12 pcf?

 

[branchburner]

Refractory cement is also a weak point. It is way stronger than fiber and this board is going to want to move (shrink) a little, maybe tearing at the mortar joint. A shape of this type would probably be produced as one piece in a vacuum formed process.

I used the nails thinking I just needed to pin it together until the cement dried. I hadn't accounted for the board shrinking and I appreciate your info. on that.
The OEM boxes are, apparently, formed as one piece.
I wonder if I should relieve the cement joints before firing and also replace the pins with sheetrock screws ? Your opinion ?
Would high-temp. silicone be appropriate for the joints or will it also fight the contraction of the board too much ?

The Harman unit is several pieces put together with what appear to be sheetrock screws.

 

[Brian VT]

I'll throw a few screws in for good measure.

 

[Brian VT]

Just a quick update...
I've been burning pretty much 24/7 for almost 2 weeks. It's working great. The original box was in poor shape when I got the stove
so I can't compare the burn of my box to a new OEM box. I can say that my burn is much more even and controlable than last year.
I can leave the primary air towards the thin end of the triangle for overnight burns. Last year I'd have to have it almost closed or it would overfire.
I can't say if the difference is due to the wood I'm burning or the box.
I've gently poked the box material with my steel tongs to feel how it's holding up. It has a crusty feel like the old OEM box that I removed but it's only a thin outside layer.
I'm very happy with it so far but the real concern is how long it will last compared to the $225 OEM. I wish I had that answer for you all right now.
I'll post an update after 1st cleaning. I burn clean enough that my chimney should be fine without sweeping but I'm a bit paranoid because I only have 1 year experience. I'll probably clean in early December. I'll have the pipe off and will be able to inspect the top of the box and I may remove the firebrick and sideplates to inspect the front and sides of the box.

 

[jdinspector]

I'm psyched for you! The even burn and ability to control the fire is EXACTLY what my stove would perform like for about 3 months of 24/7 burning after I replaced that part. Then it would slowly degrade to a difficult to control fire. I wish I had done what you've done when I still had my Resolute. I will be interested in how it holds up after one season. What did you say? You spent $80 on it? AWESOME!