Smoke stack /heat baffle

[Sweet Shady Lane]

Do any of you guys with home made barrel units have a smoke stack/ heat baffle set up or do you just have a open stack? I have a open stack and I think I loose to much heat up the stack. I am thinking if I put a baffle before the stack I would keep more heat in the barrel and get a better boil, So if anybody that has one on there set up could take some pictures and show me that would be great. thanks

[RC Maple]

I have a barrel evaporator and I have an open stack. I have read some posts here that say a damper or baffle is a good idea and some that say no. I think my setup works well though - I am able to get a good boil. You may want to try it both ways - with a baffle and without and see what your results are. I noticed when I was buying the stuff for my stack that a damper that was on the shelf was pretty inexpensive. If you have a thermometer on your stack you could get a pretty good idea of which works best.

[bowhunter]

I wouldn't recommend putting a baffle or damper in the stack. You want the stack to generate maximum draft and the damper will reduce the draft. If you want to restrict the flow up the stack and your arch is tight restrict the flow of combustion air into the firebox if possible.

[Michael Greer]

I have a circulator type woodstove in my shop. When I close the damper, there is a notable rise in temperature from the top of the stove, and a corresponding drop in chimney temperature.

[bowhunter]

The damper probably works well for your wood stove because you have a relatively tall chimney and very good draft. The high draft is pulling in a lot of excess air and cooling the stove. You will get the same response if you can restrict the air flow coming into the stove vs closing the stack damper. Many maple evaporators, particularly the small ones, have very short stacks and not a lot of draft so putting a damper in the stack is not a good idea. If your evaporator arch is not air tight, then you should install a tall (20 feet or more) stack if you want to use a damper to control or optimize the temperature.

[rayi]

When I used a barrel evaporator I used brick and sand as a ramp so there was less of a fire box. The ramp was about an inch from the bottom of the back of the pan. This forced the fire under the pan better and I got a better boil. It also forced me to cut smaller peices of wood. The key is wrist size wood and criss cross the wood to keep the fire hot and close to the pan

[silveradomaple]

Having used 2 different homemade barrel evaps and a DOMINION GRIMM 18" x 60" SPORTSMAN model, I would recommend putting a damper into the stack. While I don't close off the damper completely, I do set it at about 25 or 30 degrees angle. By doing so, I had a noticable increase in boil, especially under the syrup pan. My thought is I am only slightly restricting the heat going up the pipe, even if only for a second or two, thus allowing the syrup pan to get hotter. I would say try it....the most you'll be out is $10.00 or so, and you can always leave the damper open if it doesn't work for you.