Firing your evaporator: How full is the firebox?

[berkshires]

In this video: https://youtu.be/HQPYXBiGheM?t=1965 you can see in this firebox loading they keep the firebox loaded pretty much right up to the pan. Is this standard practice? I had not been doing this. Usually when I go to add more wood it's down to maybe 1/4 to 1/3 full, and I take that level up to 1/2 to 3/4 full. Instead it looks like they're aiming that when they load it the firebox is only down to 3/4 and they push that up to 100% full.

I can see how if you have a blower (which I now do) this might produce more heat on the pan, at the expense of burning a little extra wood. What do you do?

Gabe

[MISugarDaddy]

I generally refill my firebox when the fire is down to about 50% and then I fill the firebox to the top of the fire door. I don't try to squeeze in every piece of wood that will fit because I try to minimize the amount of time the door is open for firing. Through trial and error I have determined that I need to feed the evaporator every 7 minutes and it usually takes 7 to 8 pieces of wood to refill it to what I consider full. This keeps my boil very steady which is what I am striving to achieve.
Gary

[ecolbeck]

I don’t stuff the firebox past 2/3 full on the theory that more air circulation is better. I refill when the temp drops on my stack thermometer.

[Swingpure]

Here are a few other videos where they fill it full.

At 1:26 in the video: https://youtu.be/ndXBmXHG-DY

At 1:50 in the video: https://youtu.be/WmfKOW5X168

At 1:00 in the video: https://youtu.be/pWRZP1kayHk

[Pdiamond]

Gabe, I have that exact evaporator and I fill it right up every time. I do not R.O., and it takes about 8 minutes from start up of the fire to get a boil going.

[bigschuss]

I fill the box on my Mason 2x4 full right to the bottom of the pan.

[berkshires]

Thanks for the feedback everyone! I'll fill my firebox to the top this year, crank up the AUF, and see how it goes. I don't have a stack thermometer, but I should be able to tell a lot by boil rate (and maybe how much the stack is glowing). Hoping it ups my boil rate a bit!

GO

[ecolbeck]

I’d like to put in another plug for the stack thermometer. They’re relatively cheap, easy to install, and help you know exactly what’s going on under the pans.

[berkshires]

I’d like to put in another plug for the stack thermometer. They’re relatively cheap, easy to install, and help you know exactly what’s going on under the pans.
What would you recommend for a cheap stack thermometer?

GO

[Swingpure]

What would you recommend for a cheap stack thermometer?

GO

I would be interested in that as well, I was just going to add a magnetic one on the single wall pipe. And would also be interested in the desirable temperature range one should be looking for?

[ecolbeck]

What would you recommend for a cheap stack thermometer?

GO

I got the basic analog one from a maple supplier. Bascoms has them for $40. Helps optimize firing timing.

[ecolbeck]

I would be interested in that as well, I was just going to add a magnetic one on the single wall pipe. And would also be interested in the desirable temperature range one should be looking for?

There are a lot of variables to consider. If you have a basic setup like mine I figure 800-1000 degrees is typical. People who have secondary air (air over fire AOF) systems will be much lower. It’s important to remember that the two designs aren’t comparable.

[Swingpure]

There are a lot of variables to consider. If you have a basic setup like mine I figure 800-1000 degrees is typical. People who have secondary air (air over fire AOF) systems will be much lower. It’s important to remember that the two designs aren’t comparable.

Thanks.

I am sure that a cinderblock evaporator like mine might have different expectations than a professional evaporator. My pan maker, who also makes evaporators, showed me a picture of a truly red hot base stack and stove pipe. Last year, I never felt or checked my stove pipe, but it was never close to being red hot.

I will get one, so I can learn, and it might teach me better firing practices.

If you have a base stack and are using a magnetic one, is it okay to be on a wide part of the base stack, which would be more eye level for me.

Thanks

[Pdiamond]

Usually about three feet up from the base of the evaporator, maybe four.

[Swingpure]

Usually about three feet up from the base of the evaporator, maybe four.

All of the Amazon ones I am finding go up to 900°, I am still looking.

I believe the thermometers with the probe are for double wall pipes.

[toquin]

Yes on watching stack temp. Keeps the train (pan) rolling the same all the time. Might be full, 3/4 or half. Just be quick.

[ebliese]

If your stack is stainless then a magnetic stack thermometer might not work since some (most?) stainless is non-magnetic.

My original stack thermometer was of the kind Bascom sells. That broke on me because it could not handle the temps my evaporator puts out. I had it mounted about three feet above the base of the evaporator. Currently I use a Smoky Lake stack thermometer which worked well for me this past season. It costs significantly more than the Bascom stack thermometer though.

The higher you mount the stack thermometer, the lower the temperature will be. That may have been the problem with my original stack thermometer-too low, subject to too much heat for too long.

[ecolbeck]

A magnetic thermometer might give you a rough sense of how hot your stack is but it won’t react quickly enough to give you any useful information about when to add wood.

[Swingpure]

Can you use a probe thermometer on a single wall stainless steel pipe? It seems like it would be wobbly and a little insecure?

[ecolbeck]

I just drilled a small hole to give it a snug fit. I don’t find that it flops around or anything.

[Pdiamond]

I thought there was something on the inside that held the probe in place, against the wall of the pipe.

[ecolbeck]

I thought there was something on the inside that held the probe in place, against the wall of the pipe.

If there is I didn’t bother to use it.

[Zucker Lager]

I bent up a bracket out of stainless attached with 4 small stainless screws. Slip fit holes in the chimney pipe and the bracket that sits 1/2" out from the pipe support the thermometer and it isn't "wobbly" jay
22641

[Swingpure]

I bent up a bracket out of stainless attached with 4 small stainless screws. Slip fit holes in the chimney pipe and the bracket that sits 1/2" out from the pipe support the thermometer and it isn't "wobbly" jay
22641

That’s a clever idea!

[Pdiamond]

That is a really neat idea. Where did you get a piece of stainless like that for the bracket?

[Swingpure]

That is a really neat idea. Where did you get a piece of stainless like that for the bracket?

It looks like a piece of stainless steel gutter guard.

I have an eavestrough place by me that I will drop by and see if he has a left over for me.

[Swingpure]

It looks like a piece of stainless steel gutter guard.

I have an eavestrough place by me that I will drop by and see if he has a left over for me.

I saw some stainless steel gutter material on line that looked just like it, but seeing my eavestroughs guy today, his gutter guards were aluminum. Aluminum melts at 1221° and my stove pipe will never approach it. Just for the hec of it he also gave me some metal bracing.

I have also asked my base stack maker if the stainless steel he uses in the base stack is magnetic or not. Some stainless steel is magnetic and some is not.

Edit: I heard back from the base stack maker and he says magnets will not stick to the base stack.

https://share.icloud.com/photos/03azNr7-UcENtMMFJBjrcP0hA

[Zucker Lager]

That is a really neat idea. Where did you get a piece of stainless like that for the bracket?

Look on ebay for Perforated Sheet Stainless Steel. I bought it originally to make a filtering funnel but it cut off too much of the flow so I used an oven baking rack instead and had this laying around. It bends easily and the holes are there for the screws already haha jay

[Swingpure]

I am the worst tin sniper cutter in North America, but I did make a bracket to hold the probe thermometer on the single wall pipe. It should work. I haven’t drilled the hole for the probe yet until I get the thermometer and get the probe size.

The picture attachment on the forum is working again for me.


22644

[Pdiamond]

Thanks jay

[Swingpure]

I purchased my stove pipe probe style thermometer this evening and drilled a hole in the aluminum bracket for it. Now I just need a base stack to attach it to.

https://share.icloud.com/photos/03bizteITrv_rrf7uf0-tKitQ

22650

[bmbmkr]

https://www.rothsugarbush.com/product/stack-thermometer-0-1000-f/