arch board

[maplemaker]

Has any one have any expierence with arch board because i have never seen it.My arch needs rebricking so I was wondering if I took the brick out if I could put a layer of ceramic blanket then cover it with arch board my arch is wood fired or would the wood ruin the arch board.Any thoughts would be great.

[3rdgen.maple]

No wether you use blanket or arch board in the firebox you need the brick to protect it. Archboard is easier to work with but more fragile than blanket. Most if not all use one or the other.

[Dennis H.]

The archboard is more firmer than ceramic blanket. The blanket can be compressed which will lower the insulating value.

I used archboard behind the firebrick in my arch, really easy to work with all you need to cut is a straightedge and utility knife.

Not sure if anyone near you sells archboard but ceramic blanket can be picked up at a pottery supply dealer near you. So there is goods and bads to both.

[RunInCircles]

In my first season using a "real" evaporator, I was strongly urged to use arch board. I balked at the extra expense, but at $80 for the whole arch (30x8)--well, compared to a lot else in this hobby it wasn't so bad. I've no experience without it, but finding that I could put my hand up against the side of the arch and only feel slight warmth after hours of boiling indicates to me it's doing a darn good job directing the heat where I wanted it.

I was also surprised at how easy it really is to work with. It's like cutting through foamboard.

[70 Buick]

Look for any refractory supply store in your area
thats all I did & was shocked to see how many there was, but I do live in a big city

[vernon]

I have been looking for arch board or ceramaic blanket to put in my 2x6 evaporator before i firebrick it and can't find a suppier in Nova Scotia to buy it from? The best price I can find on line is (refractory depot) for $75.00 and $110.00 shipping. Would like to find one locally. Thanks Vernon

[BryanEx]

Kevin Maccormick just outside Springhill, NS should be able to source it for you vernon. Not a lot of info on his website but all his contact info is there;

http://www.maplepower.ca/

- Bryan

[vernon]

Thanks BryanEx..will give him a call tuesday...Vernon

[3rdgen.maple]

If you cant find it there ship it in from Bascoms in NH. Iwould have to look it back up but archboard is like 7 bucks for a 1 foot by 3 foot piece.

[KenWP]

You wouldn't believe the price difference between the US and Canada for arch board. It is almost cheaper to have it shipped from the States then buy it here. I can find lots of ceramic blanket but D&G was the only place that had arch board .The other companies won't deal with me since I speak english.

[Brent]

If you just want moderate insulation, the archboard the Bascom or The Maple Guys sells will do a pretty good job. It's green, and much like Roxul mineral wool with a bonding agent applied to make it stiff. As noted above it is fragile. I got some from Bascom a few years ago for my 2x6 rig. With the 1" board and full bricks inside, the side of the arch were so hot on the outside that any slopped syrup ( like who would ever do that ) scorched and burned.

Last season I got a new-to-me 2-1/2 x 8' rig. After much looking around I got a load of 2" Duraboard RG from Unifrax in Niagara Falls NY. It was pricy but you could put your hand on the sides after 5 hours of boiling. I could still scorch syrup on the top of the rails where the pans sit, but that's all.

Aside from being much easier to clean, the sugar shack stays cooler, the risk of accidental burning of me or a visitor is reduced, and the thermal efficiency of what you're burning is much better. (heat coming off the sides does not boil anything.)
Elsewhere I've posted the R value of firebricks and its almost nothing. All the insulation will come from blankets, archboard or whatever you put in between. The ceramic board is even used in nuclear reactors. It's about as good as it gets.

http://www.unifrax.com/web/UnifraxHome3.nsf/AllDocuments/8AAA501C5FD37B0585256C3E00601654?OpenDocument

They shipped to us in Ontario with no problems. It's cheaper to put the purchase on the credit card with their US$ prices. The prices are posted on the page linked above.

PS under the flues I did not put any bricking and the stuff still looks brand new after one season.

[GramaCindy]

If you just want moderate insulation, the archboard the Bascom or The Maple Guys sells will do a pretty good job. It's green, and much like Roxul mineral wool with a bonding agent applied to make it stiff. As noted above it is fragile. I got some from Bascom a few years ago for my 2x6 rig. With the 1" board and full bricks inside, the side of the arch were so hot on the outside that any slopped syrup ( like who would ever do that ) scorched and burned.

Last season I got a new-to-me 2-1/2 x 8' rig. After much looking around I got a load of 2" Duraboard RG from Unifrax in Niagara Falls NY. It was pricy but you could put your hand on the sides after 5 hours of boiling. I could still scorch syrup on the top of the rails where the pans sit, but that's all.

Aside from being much easier to clean, the sugar shack stays cooler, the risk of accidental burning of me or a visitor is reduced, and the thermal efficiency of what you're burning is much better. (heat coming off the sides does not boil anything.)
Elsewhere I've posted the R value of firebricks and its almost nothing. All the insulation will come from blankets, archboard or whatever you put in between. The ceramic board is even used in nuclear reactors. It's about as good as it gets.

http://www.unifrax.com/web/UnifraxHome3.nsf/AllDocuments/8AAA501C5FD37B0585256C3E00601654?OpenDocument

They shipped to us in Ontario with no problems. It's cheaper to put the purchase on the credit card with their US$ prices. The prices are posted on the page linked above.

PS under the flues I did not put any bricking and the stuff still looks brand new after one season.

Brent,

After you put the duraboard in, did you also brick the evaporator?

[Brent]

I lined the firebox area with half bricks.
under the flues I had nothing.

This year I am going to lay a sheet of metal, likely stainless under the flues
so I can put a brush on a pole in there to brush the flues without damaging the ceramic board.

[RUSTYBUCKET]

Brent

With my new 2x6 scheduled to arrive within the next week or two, your post about the Unifrax Duraboard caught my interest. Was the main reason for purchasing the Duraboard based on the safety issue or did you look to this product to help increase the boiling rate on your rig? The archboard I was looking to line my new arch with is rated at 1900 degrees. I see the Duraboard is rated at 2600 degrees. With the price difference being 3-4 times as much, I'm curious if there was a sufficient increase in boiling rate to warrant the purchase.
Also, did you need any special tools to cut the Duraboard ?

Thanks

Russ

[Brent]

Russ

what I really wanted was the best insulation possible. When you look at the price, keep in mind that what I selected is 2" thick.

I bought the evaporator used, 5 years old. The previous owner had put in a thin layer of ceramic and lined it with full bricks. Double rows in most places. From the damage to the galvanized sheets on the side of the arch, it was obvious there were heat issues. Furthermore they had hung an additional full panel of stainless on the outside of the rig .... all around. I assume this was because it was too hot to stand beside. I would guess the double rows of bricks were an attempt to control the heat as well.

It took me a lot of digging but I eventually found a spec for the insulating value of firebricks. I don't have it handy but if you search Unifrax on this site you'll see the earlier thread with the reference. Firebrick has nearly no insulating value. It stands the heat well and takes a beating. My first Phaneuf rig I lined with 1" archboard and it was pretty toasty. After 5 hours of boiling you would melt any modern ski jacket shell that touched it.

With the Unifrax board you can put your hand on the sides for as long as you want. They get warm after 5 hours but that all. The rails still get hot but not as hot as with the thinner archboard.

All that lost heat is doing nothing but heating the sugar shack ... not boiling sap.

So the sugar shack is cooler, we use less wood, and the sugar shack is safer. I'd do it the same way again without a second thought.

[Brent]

Russ

You asked about cutting.
I used a normal fine tooth wood hand saw. The material is pretty light. You get a fine powder when cutting. Like working with almost any insulation, it ain't good stuff to inhale so I had a shopvac nozzle right beside where I was cutting.

The boards are absolutely rigid. The closest thing I've seen to this before is the foam toffee candy we used to get 40 years ago. It's pretty tough. I never tried but I think it would be pretty hard to push a pencil through it.

It is not cheap, but if you compare it to 2" of ceramic blanket, the prices start to get closer. The problem with a thick ceramic blanket is that your brick doesn't get anything rigid for backing and the impacts of tossing you wood in ( like I'm the only guy that throws it in ) loosens you bricks. Even the green archboard does not maintain much rigidity after a few good cooks.

Unfortunately one more example of you get what you pay for.

[Brent]

Russ

too many questions in one post

I don't know if it affected the boil rate but I don't think so. I regulate my stack temp with the variable speed blower, and it was the first year with this rig. What I do think was happening was that I would have been dialing in less air to get the same stack temp. That means less wood consumption.

Now stay tuned on this idea till March. This year I'm putting in a high pressure blower 5 PSI. The blower in the Inferno arch puts out less than 1 PSI. I think by using higher pressure and a bunch of very small holes I'll get more air jets pentrating deeping into the flame / wood gas heart of the fire and getting better combustion while blowing less cold air in ..... we'll see. More interesting still, we'll see if we can understand what we've done.

[RUSTYBUCKET]

Thanks for the reply Brent.

[BryanEx]

Brent... I'm interested in this as well. How was the board shipped to you?

- Bryan

[GramaCindy]

I lined the firebox area with half bricks.
under the flues I had nothing.

This year I am going to lay a sheet of metal, likely stainless under the flues
so I can put a brush on a pole in there to brush the flues without damaging the ceramic board.

Just curious Brent, I am seriously considering getting some RG, but why not the 1" vs. the 2"? I only have a Mason 2x4 and a 2" board and firebricks would take up a lot of my firebox?

[Brent]

Brent... I'm interested in this as well. How was the board shipped to you?

- Bryan

They put them on a skid and shipped them UPS. For the 2" boards they packed 2 in each of the cardboard boxes. I got 6 boards shipped to Toronto
for about $1,000. all in. Not cheap but great stuff.

[Brent]

Just curious Brent, I am seriously considering getting some RG, but why not the 1" vs. the 2"? I only have a Mason 2x4 and a 2" board and firebricks would take up a lot of my firebox?


2" would cramp the inside, especially if it has sloped sides like most small rigs do. The Leader Inferno arch has vertical sides so there was still lots of room.

The 1" RG board had a lot more insulating value than the 1" green archboard I had on my Phaneuf. But I had a gut feeling that 2" would give me what I wanted. Our sugar shack is pretty narrow and we get a fair number of visitors so I wanted cooler sides for safety, as well as efficiency and ease of cleaning. The 2" gave me all. Like the engineer said when asked why a VW Beetle had 4 gears. 3 wasn't enough and 5 was too many. Admitedly it was a guess that 2" would do it. If I was doing a new rig this year, I'd scratch my head about saving a little and going 1-1/2" but I think I'd end up with the 2" again.

[Brent]

Here's a link to our web page showing the whole operation of the rebuild and insulation.

http://www.duffyslanemaple.ca/Leader_evaporator/Leader_evaporator.html

In the shots at the top of the page taken by the previous owner, you can see that even with the additional stainless sheet outside of the original Leader galvanized skin, the syrup was still scorching on the sides. And it was double bricked inside.

That page also has the chart showing the thermal conductivity of different refractory insulating material. No contest.

The 3rd picture from the bottom shows the stainless tubes in place that I was planning to use for the high pressure air injection. About the same time I was at this stage, I got a hernia so priorities got re-arranged. I just put it back together and started boiling about 3 days after the pictures were taken.

[RUSTYBUCKET]

Brent -

Still pecking at you with a question on the Duraboard. Since you have some experience with this product, in your opinion, with the Duraboard in place what is the least distance you would have between your evaporator and a combustible surface ?

Thanks


- Russ

[Ed K]

Brent, Do you have any more pics of your air piping.Does it cross the front? And what size holes did you drill into the pipe and what angle from the horizontal center of the pipe?
I'm just at the insulation part of a whole rebuild of my 2x8 water-loo.
Thanks,

[Brent]

Brent -

Still pecking at you with a question on the Duraboard. Since you have some experience with this product, in your opinion, with the Duraboard in place what is the least distance you would have between your evaporator and a combustible surface ?

Thanks


- Russ

If you had a side of the evaporator with no float boxes or valves I think you could tuck it up to within maybe 4 to 6". The only reason I'd give it that much space is the the rails that the pans sit on still gets very hot. I haven't had the accident yet but I'm sure a second or less of contact on bare skin would cause a bad burn. Sap that hits the rail will sizzle. Two inches below the rail, you can put your hand on the stainless side and leave it there for as long as you like.

If you put a little bit of protection, like a strip of sheet metal about 6 inches wide and a foot longer than your evaporator at each end, I think you could go down to maybe 2 - 4" clearance. I'd space the sheet metal 1/2" off the wall to let air flow behind it.

In our small sugar shack I only have 24" behind the evaporator, just enough to get there to fiddle with the float boxes, which are on the wrong side for our layout. The walls at 24" are cool.

Someone else asked in a private message, exactly which of the Duraboards I got. It was the 2" thick RG.

[Brent]

Brent, Do you have any more pics of your air piping.Does it cross the front? And what size holes did you drill into the pipe and what angle from the horizontal center of the pipe?
I'm just at the insulation part of a whole rebuild of my 2x8 water-loo.
Thanks,

The stainless pipes you see in the pictures of the arch rebuild and insulation, did not stay in last season. I got a hernia two days before the first boil and could not get it finished.

BUT

The previous owners, who screwed up insulating, were quite creative about getting some air over the fire. The original Inferno arch blew all its air up through the grates. This was modified to take a 4" pipe under the grates to a plenum under the front door, up the sides of the door and across the top, with about a dozen or so 3/8 or 1/2" nozzels to give air over the fire. The 4" pipe had a dozen or so holes in it to give some air under the fire.

I tried the stainless tubes 2 seasons ago on the Phaneuf 2x6 with small holes every 4" or so and a medium pressure blower. The results were great. When the blower fired up you could see the flames change to whiter yellow and some blue flickers. Gassification. The sound changed pretty dramatically too. It rumbled.

This year I've got a GAST regenerative blower that will give me nearly 10 times the pressure. It's going to be fun to see how it goes.

[Greenwich Maple Man]

The stainless pipes you see in the pictures of the arch rebuild and insulation, did not stay in last season. I got a hernia two days before the first boil and could not get it finished.

BUT

The previous owners, who screwed up insulating, were quite creative about getting some air over the fire. The original Inferno arch blew all its air up through the grates. This was modified to take a 4" pipe under the grates to a plenum under the front door, up the sides of the door and across the top, with about a dozen or so 3/8 or 1/2" nozzels to give air over the fire. The 4" pipe had a dozen or so holes in it to give some air under the fire.

I tried the stainless tubes 2 seasons ago on the Phaneuf 2x6 with small holes every 4" or so and a medium pressure blower. The results were great. When the blower fired up you could see the flames change to whiter yellow and some blue flickers. Gassification. The sound changed pretty dramatically too. It rumbled.

This year I've got a GAST regenerative blower that will give me nearly 10 times the pressure. It's going to be fun to see how it goes.

Do you know the size of the blower on your arch. I'm not sure what is on my Inferno but feel that I could go bigger and get more gph. Any thoughts? The blower is the stock blower that came with the arch from Leader.

[Brent]

I'd have to crawl under to see but I think it is 1/3 Hp.

With the mods that put some air over the fire I never came close to reving the fan to full speed. I tried to run about 1100 deg on the stack about 4' up - internal probe. This was a little low of optimum, which I think in this rig is 1200-1250, but I boil alone and I was hurting a bit, and I was trying to learn a bigger rig, drop flue and a steamaway.

I beleive from a lot of posts I've seen about guys putting air under the fire, that many are using too much air. I don't know about your sugar shack but the air in mine is cold so I don't want to blow more in than it needs. The air under fire style, I think, does not mix the oxygen well enough to get secondary combustion of wood gas. If I never get any better efficiency than last year, I won't be disappointed. 85 to 90 gallons per cord. But I think the stainless tubes to inject air are the simplest way to go and you can get the oxygen were it is needed .... up high and near the back of the slope. We'll see.

[RUSTYBUCKET]

Thanks for the reply Brent.

[RUSTYBUCKET]

The Unifrax board arrived the other day. If anyone is thinking of ordering, they do not ship partial orders and they would not ship UPS or Fed Ex.

Brent, if you see this. Did you have a filter tank you were trying to sell a couple of months ago?

Thanks

- Russ

[Brent]

Russ
They shipped to us by UPS Freight - it was a full skid - to much for the parcel service.

Yes and the filter tank is still available.

[RUSTYBUCKET]

Brent -

My order was just one box. Probably accounts for the difference.
Do you have a price on the tank and an approximate weight (for shipping costs)?
Thanks

- Russ

[RUSTYBUCKET]

Going to open this topic again with another question for Brent. In a previous post in this thread, you mentioned that the first year you fired your rig with the Duraboard, only the firebox was bricked. How did the Duraboard, without the brick, stand up to the heat? The reason for my question is that the instructions for bricking my evaporator (2x6 drop flue with flue pan drain) call for the placement of 1" brick, as opposed to the standard 2" brick, under the pan drain for clearance reasons. I currently have the 1" Duraboard in this location but wonder if I should replace it with brick since it will be subject to open flame (wood fired).

I'd like to hear your opinion on this.

Thanks

- Russ

[Brent]

When I put the Duraboard under the flues I had the option of putting in 1" of insulation and 1" of bricks OR 2" of insulation. I elected to go with 2" of insulation. After the one season it still looks like brand new. Just a little grey ash here and there. This year I am thinking of covering it with a stainless sheet so I can get a bit agressive with a flue cleaning brush mid-season. I can see no reason to waste your heat warming up brick which will transfer a lot of heat out through the bottom of the the arch.

Even in the front fire box area I did not cover the Duraboard all the way to the top. There is about 5" of it exposed above the brick. I was more careful than normal firing, and only whacked the boards once with a log. It made a little gash about 1/2" long and 1/8" deep. Nothing to worry about in a 2" thick board. No effect whatever that I can see from the direct exposure to the flames.

The only thing I don't like with this product is the price ... but like I've said before, I'm so happy with the result that I'd do it the same way again.

[huntoonmaple34]

you can purchase High Density Insulation Arch Board 1" thick x 12" wide x 36" long it will withstand 1900 deg. for $8.75/3'
at www.bascommaple.com

[RUSTYBUCKET]

Thanks Brent.

Huntoonmaple - Based on comments from this group, I did use the arch board from Bascom's to protect the roof rafters where my stack exits through the roof. Thanks

- Russ

[RUSTYBUCKET]

Brent -

Even with the 1" Unifrax board, I was very pleased with this years results. I'm giving some thought to removing the 1/2 bricks along the bottom of my arch, adding 1" of the generic arch board hoping to increase the heat transfer to the flue pan.

As noted in your post from 11-16-11, did you add the stainless cover this year ? If so, any problems while running your rig this year ?

Thanks

- Russ

[Brent]

Well done Russ, glad it worked well for you.

I ended last season with a hernia that screwed up the whole summer work season so I never did get the cover over the
Unifrax under the flues. I also did not clean the flues much during the season, and the stainless was to protect the insulation
while I thrashed around with a brush on a 10 foot pipe.

The thing I can add is that the preheating with the propane "flame thrower" seems to have made a pretty big difference
in the amount of soot that accumulated. There was no baked on creosote like deposits at all. Furthermore "IF", big if,
I get around to putting in the full high pressure low volume air injection system, I think the soot will get burned to a large degree
and the flues will stay even clean.

And if ..............

[RUSTYBUCKET]

Brent -

Do you feel there would be much to gain, i.e. more heat to the flue pan, if I replaced my 1/2 bricks along the sides of the arch with another layer of arch board covered with a piece of stainless. Basically do to the side of the arch what you did to the bottom.

Thanks

- Russ

[Brent]

Well my guess is that the rig would heat up faster and cool down faster with the bricks replaced with any kind of light
insulation. I don't think you'd see the difference on start up, but it would sure help cool down a lot faster. That might save
a round or ropy syrup one day. But I think the biggest effect on syrup going ropy comes before it gets into the eveaporator, ie
in storage tanks.

Did you put the Unifrax under the bricks under the flue pan ???
If you did then you could use the less expensive Bascom archboard against the bottom sheet metal and the Unifrax on top of the
green board from Bascom.

If it were my rig, I'd get rid of the bricks, but it would be down the "to do" list a ways.
If your list is short and priorities are low, go for it.

[RUSTYBUCKET]

On both the sides and the bottom of the arch, the Unifrax was placed under the bricks. My thoughts for removing the bricks entirely refers back to your post (see below) about the insulation properties of brick vs. arch board. More insulation = more heat inside the arch.

Previous post.......the thermal efficiency of what you're burning is much better. (heat coming off the sides does not boil anything.) Elsewhere I've posted the R value of firebricks and its almost nothing.

Thanks

- Russ

[NHMaple]

lynnmfg.com usually get it next day!

[RUSTYBUCKET]

Going to revisit this thread to add an update for Brent and anyone else that might be interested. For the 2013 season I pulled all the firebrick from my rig except the firebox. On top of the existing Unifrax board, I laid in an additional 1" of generic arch board from the end of the firebox back to the stack (sides and bottom). Comparing the 2012 season to 2013, this resulted in a noticeable temperature difference on the sides of the arch while boiling. In addition to the added arch board, I placed a deflector plate at the end of the firebox. Boiling rates for the 2012 season averaged 28-30 gph (first year with the new rig). For 2013 the average was 38-40 gph. 2x6 drop flue, wood fired, natural draft.

Thanks Brent !

- Russ

[Brent]

Glad to hear you got good results too. We the sides of the rig are only about 100 deg F you know that 99.9% of your heat is available to the pans. How much gets adsorbed into the pans I guess depends on how fast you blow
it up the stack. I go for minimum blower speed that will keep the stack at about 1100 F and I think the efficiency is pretty much optimized. Not the fastest boil, but the best heat out of the wood.

I put the 2" Unifrax up the sides under the flue pan and then laid in the bottom so the bottom held the sides in place. No room for anything more.

Got to get life organized so we can make syrup next year. Missed it a lot this season.

[SeanD]

Russ,

That's a huge increase for a pretty simple modification. Would you mind posting pictures of the deflector plate you mentioned? Did the arch get much narrower inside after adding the extra board on the sides? Was the wood you burned and your sugar levels consistent between the two years?

I have a flat pan in the back, but if I can get a fraction of the increase you got, I'd be happy.

Thanks,
Sean

[RUSTYBUCKET]

Sean - I feel that the boiling rate I achieved this year can be attributed to a combination of changes, not just the additional arch board itself. 2012 was the first year with the new rig so caution during operation was a priority. This year I was much more aggressive. Sugar content was about the same for both years. This years wood was a little drier and I fired differently based on comments by others on this board (did not fill the firebox full up).

The reason for the deflector plate had more to do with pulling finished syrup off the front pan than the boiling rate. Last year I was not able to achieve 7 degrees in the front pan. At the end of the firebox was a piece of 2" angle iron which served as a resting point for the grates. I simply welded a 6" piece of flat stock (the width of the firebox) to the angle iron to help deflect the flames up onto the front pan. With this plate in place the rig easily reached 7 degrees in the front pan.

Hope this helps.

Thanks

- Russ