Fire around the Stack!

[CPlace]

Started out with great day of boiling, we were burning a lot of rocket fuel (pine) and at the end of the day we were standing proudly around the evaporator talking about how hard we were able to get the boil to roll in the pans. After the last firing, we noticed flames appear around the stack!:o. I thought I had plenty of clearance around the stack and installed arch board where the stack goes through the roof as added precaution. After getting the fire out and tearing down the arch board, it appears the arch board was trapping the heat in versus deflecting the heat. Fortunately, the damage is minimal, and we can chalk this up as a war story in the sugar shack. We will have some serious modifications and cleaning to do tomorrow. We are going to get the saws out and create even more clearance to the stack, but thought I would check with other sugarmarkers for any suggestions as well.

[gmcooper]

Give plenty of clearance if you can. I used to use 29 gauge sheet metal as a heat shield on the framing around my stack with a 1" air space between the metal and wood. Good thing you saw the problem before it got any worse.

[lpakiz]

Good thing you saw the problem BEFORE YOU WENT TO THE HOUSE!!

[RileySugarbush]

I agree with Cooper. Best bet is to reflect the heat and make certain there is an air space behind the reflecting metal.

[KevinS]

the air space is critical. it is the only thing that stops the conducting of heat to the wood behind the shield on long cooks... and how often does a sugar maker do short cooks? pretty dang rare.

[Sugarmaker]

We had a similar problem, and like you were lucky to be right there to get it out. We added another larger diameter of stainless steel to provide a air space around the pipe. We also watch our stack temps and try not to allow the temp to run away. Soooooo glad you caught and corrected this. In hind site I think we all should have double or triple wall with at least air gaps in them running through the rafters and out through the roof jacks.
Regards,
Chris

[birdmancf]

Good thing you caught it, hope you don't have too much rebuild. Here's what I have done based on the suggestions of others here on the Trader. You can decrease the amount of clearance by half for every layer on heat shielding and air space. If I were to redo mine, the layers would be wider than the 3-1/2" which I had materials for. As my stack temp runs 600° -700°F I'll definitely keep an eye on it with everything else. Good luck.
Chris

[birdmancf]

Oops, here's the photo.9506

[tendermason]

I ran metalbestos chimney from below rafters up thru roof. It needs 2" clearance to framing

[CPlace]

Thanks for the suggestions. Hindsight being 20/20 I would have done things differently! After a few modifications today, I have a much better and safer set up.

[Revi]

Birdman's looks pretty good. We have some space around ours also. We have had it for about 10 years, but I am going to look at it again now!

[CPlace]

Yes, birdman's does look good; I ended up changing mine to a similar set up.