Is the stack in this picture a problem?

[Starting Small]

Is the stack in this picture a problem and if so should I do anything about it? This was last year and just came across this picture. I figure to keep it going like this since it gives us the best boil when it turns red hot like this. The boil rate is great and this only happens when we put the blower on. 6240

[spencer11]

my 6" stack on my old evaporator last year was glowing red, so i dont see a problem with it, if thats when you boil best, as long as you have enough wood you should be fine

[maple maniac65]

my sons 2x3 does the same thing. I buy him a new elbow every year because the heat will weaken the elbow and i am concerned that the following year it may collapse with the pipe being that hot. I thought about a clay elbow to take the heat but they are more expensive than just replacing black pipe.

[nymapleguy607]

How is the firebox laid out on that pan, does it run the entire length of the pan? I would consider adding a baffle below where your stack inlet is. Insulate it with some ceramic blanket and maybe make it around 6", mainly to force the heat and flames to roll back towards the front instead of going right out your stack. Then run the blower and it should boil even harder. Running it red might look cool but your wasting alot of heat.

[red maples]

If your concerned then I would get a stainless one. it will turn a pretty copper color. I get lots of compliments on my copper base stack people don't know its stainless!!! The stainless can take the heat better its also thicker as long as you get a good one. and you won't have to replace it every year.

[OldManMaple]

It might be a problem if that stack is attached to insulated chimney. The thing to remember with Metalbestos or Duratech or ANY factory built chimney listed to UL103HT is that these are residential type chimneys with 1000 degree F maximum output under normal operating conditions. They're tested to 2100 degrees F as in the event of a chimney fire, which is normally short in duration. If you are going to use factory built chimneys and run it higher than 1000 degrees F, the chimney pipe should be installed with more than the minimum 2-inch clearance to combustibles to be on the safe side (and then use the warranty card to light your first fire).

[farmall h]

Starting small is that a "factory" built arch? If I were you, time permitting...modify the arch to accept a base or make your own base (box) so the pipe doesn't require an elbow. In order for the back pan to boil the flames need to go between the pan and whatever insulation you have (be it sand or fire blanket). Don't know what your arch looks like on the inside so I really can't comment beyond this.

[wildlifewarrior]

Hi everyone staringsmall is my brother we syrup as a team and he is on a cruise so someone has to pick up the slack. Haha. Anyhow I don't know if the pan is factory or not ( that was his deal) we didn't make it ourselves. Te arch itself is about cut in half from back to te middle and up to the bottom of the pipe inlet, to force the heat up under the pan from the front to the back. The pan itself has the channel going from back to front not side to side ( I think that's why someone asked about a back pan) in three sections.

I will try to post a picture tonight.

I understand that you want a fast hot fire to get I the maximum boil, but I feel like there is a lot of heat lost if the stack gets that hot.

Thanks guys
Mike

[shane hickey]

I understand that you want a fast hot fire to get I the maximum boil, but I feel like there is a lot of heat lost if the stack gets that hot.

Thanks guys



Thats how felt when i watched 11000 dollars go into the arch and,
Out of the stack. But yes the more btu the more sap you can get rid of.
I think my pans are rite at the melting point with as much gas
That i put in it.

[maple flats]

I'd use a new stack and elbow each season. A 24 ga stack will take that for 1 season but might not a second year. If you expect to stay with that evaporator, try to find a more durable stack material, otherwise just replace annually for safety sake .

[twin6]

Anyone else see a problem with rig efficiency? I'm with nymapleguy607 and would work on increasing transfer of heat to the pan, either inside the arch or perhaps by experimenting with a damper in the stack. You can replace the elbow with anything you want, but you'll still be wasting heat IMHO.

[wildlifewarrior]

Thanks guys for all the help. I think I will try to put a dimmer switch on it to get the ideal "sweet spot" (pun intended) where we have a great boil but not cooking the pipe.

Mike

[wiam]

Thanks guys for all the help. I think I will try to put a dimmer switch on it to get the ideal "sweet spot" (pun intended) where we have a great boil but not cooking the pipe.

Mike

Be careful with the dimmer switch. That will burn up some motors. I have a damper over the intake on my blower instead.

[wildlifewarrior]

Be careful with the dimmer switch. That will burn up some motors. I have a damper over the intake on my blower instead.

That's a great idea thanks!
Mike

[bowtie]

your stack looks similiar to mine when turn up the blower on my 2x4 mason/blower, i installed a dimmer switch and just "tone" it down to keep the stack temp down. i am throwing around the idea of running my feed line into the stack and coil it around on the inside and them back out into my "pre-heater" pan to try to utilize the wasted heat going out my stack not sure if this will work but was going to mess with it a little.

[motowbrowne]

seems like a bigger evaporator might be in order. Could probably keep a 2x8 boiling with the same amount of wood, but if wood is free and you don't mind splitting it, just make sure no one touches that thing and keep stoking.

[wildlifewarrior]

Last year was our first year with it so we are still trying to figure out the kinks. We were burning a lot of soft wood so the blower really ate it up. We were throwing the idea around of wrapping it with copper tubing into the preheater to utilize some of it. It didn't run that hot all the time. I would just like to get the max boil out with the min amount of fuel spent.

Mike

[farmall h]

Mike can you post a picture of the inside of your arch (with out the pans on)...maybe (as stated earlier)you may need some sort of baffle or deflector to keep the heat from entering your stack...plus putting a damper on your blower to adjust for optimal airflow is better than a dimmer switch(safer). I would think if your running a blower with dry softwood you must be loading in wood every 5 minutes! Go with just the draft door open(no blower) when burning softwood.

[wildlifewarrior]

Here is the picture of the arch itself when we mudded it up last week, we removed the blocks which took up the back of the arch we were using to direct the heat along the bottom of the pan. We were using cinder blocks to focus the heat up (replaced this year), they only went up to the bottom of the outlet hole for the stack. When the blower is on, the boil is fierce, but both my brother and I see that ALOT of heat is escaping out the pipe. We were loading wood about every 8-10 minutes, maybe a bit less but around there.

http://i178.photobucket.com/albums/w260/Thewildlifewarrior/photo-2_zps7c41a478.jpg

Thanks for the help guys.
Mike

[motowbrowne]

It seems like a baffle would really help keep some heat in the stack. It'll need to be pretty heavy duty by, but if you look at the inside of a modern type woodstove, the flue gas usually has to go to the front of the stove before it can go back and up the chimney.

[Flat Lander Sugaring]

i posted a pic of the same thing of a 5x10 base stack either here or that other site. as long as it isn't transferring heat to a wall or flammable product you be ok

[johnallin]

The Half Pint I used to run was bricked up with a "false wall" about 8" forward of the flue. It came to within about 2-3" of the bottom of the pan, slowed the heat loss down and forced it up towards the bottom of the pan before it went up and out.
If you do a search for the half pint, I think you'll see some pretty good pix and drawings as to how they were set up. Good Luck this season.

[wildlifewarrior]

So you reduce the size of the arch? Did that increase your boil rate by decreasing the air movement?? Normally we have blocks in there to direct the heat more up. would u put the wall ontop of the blocks?
Mike

[johnallin]

By adding the fire wall yoiu are holding the heat in for a longer period of time and you are correct, you are reducing the size of the fire box somewhat, but the the hot gasses are now forced to rise up and climb over that wall.

I left about a 3" gap between the pan and the top and actually played around with holding the heat back further by placing pieces of fire brick on top with 1" spaces between, same idea as a damper in the pipe.

You don't need to mortar all this in place until you see if it works on your rig - just be carefull firing so you don't knock it over. See how/if it works and then give it a try if you see any increase in boil.

Try this link to Leader's Half Pint and click on the Instuction Manual. http://www.leaderevaporator.com/p-285-leader-half-pint-evaporator.aspx

Somewhere around page 8 they begin to talk about the fire wall. Have a great season.

[wildlifewarrior]

Thanks John, that helps a lot I appreciate the link, it makes more sense now.

Mike

[MarkL]

The fire wall is a good way to keep the heat in any wood-fired device. I used to be a potter and we called it the 'bag wall' but it served the same purpose: force the heat up to where you want it before it exits the flue.

[MarkL]

...I would think if your running a blower with dry softwood you must be loading in wood every 5 minutes! Go with just the draft door open(no blower) when burning softwood.

I'm burning only soft wood and thinking of making a blower for my Leader half-pint - do you think that's a bad idea? Will I just burn the wood too quickly?

MarkL

[farmall h]

MarkL, I'm just saying try it without a blower on soft wood...I only burned softwood slabs on our 4 x 12 until they were not available. We installed a blower because we are all hardwood now. Burned softwood slabs for 25 years...no problem getting a good roaring boil. Guess the smaller arches are designed differently.

[MarkL]

We'll see how it goes this season. I am using about 90% soft slabs this time around. Last year it was about 50/50.

The half-pint is a great improvement over my earlier setup (a hotel pan on cinderblocks in the driveway!) but it is challenging to keep the boil ripping, even with the pan low.

MarkL