The best way to do a metal chimney?

[Loafin]

Whats the best way to attach a metal chimney to the firebrick flu??

[peter]

Re: The best way to do a metal chimney?

I attached mine with hardened self tapping bolts. Seems to be working well. I have a shelter next to mine that supports the upper part of the stack.The shelter keeps the rain off me and my pizza. We have some wicked winds here in West Michigan so the support is necessary. If your oven is sheltered from wind you may not need any upper support.

[Jed]

Re: The best way to do a metal chimney?

Hey Loafin,

There are a couple of mechanical connections you can implement; anchor bolts through flange style connections.

I chose a different style. The pictures show the basic process. I used a chimney flue tile, larger than my metal chimney pipe, and grouted the two parts to the masonry structure. I expect the metal will corrode away over time, but it is pretty dry here so it should take a bit of time...

Good luck with your build, and keep us posted with pictures!

JED

[kebwi]

Re: The best way to do a metal chimney?

On the same topic, how crucial is an anchor plate? I haven't quite figured out how I will attach my pipe to the vent without one, but I didn't really want to spring for a plate if I could avoid it. Haven't found a used one yet.

[nissanneill]

Re: The best way to do a metal chimney?

Loafin
There are numerous methods available and everyone has their own interpretation and ideas as what to do.
I made mine out out scrap stainless that I had lying around which was simply dyana bolted into the bricks and the 8" flues sat on top in a tight ring welded on the top of the funnel shape.
I also made one for a deceased friend, (the last 2 pics) which was bolted and sealed into his rather smaller and crowded chimney space.
I hope this helps you, very easy to make and very efficient in removening and venting your oven. Make it large enough and you will get no smoke out the front of your oven.

Neill

[Neil2]

Re: The best way to do a metal chimney?

Buy one of these (floor box) off the shelf for $10. Available at most hardware stores or HVAC stores in all kinds of sizes.

Set it in place with a glue gun. Use it as the inside form for a refractory mortar surround about 1 inch thick. Attach your metal chimney and continue the mortar up about 3 inches or so to form a "socket"

The thin metal floor box will burn and rust out the first year. (Watch for the pieces to start coming loose and pull them out.) Then don't tell anyone how you did it when they ask about the nice smooth vent to chimney transition you have.

[Loafin]

Re: The best way to do a metal chimney?

Hey Neil
Will the mortar be strong enough to hold the chimney??

[shuboyje]

Re: The best way to do a metal chimney?

I used the smallest tapcons I could find and was shocked how well they held in the firebrick. Part of the trick is to use a standard drill with a masonry bit...the hammer drill is to much.

[Neil2]

Re: The best way to do a metal chimney?

"Will the mortar be strong enough to hold the chimney??"

So far (three years). My chimney is a double wall 7 inch diameter and is 18 inches high.

[rhollman]

Re: The best way to do a metal chimney?

I am in the process of welding togehter a stainless steel anchor plate which consists simply of a square piece of flat sheet stock with a 8" hole in the center. A 1/2 inch tall ring will be welded around the perimeter of the circle. Four holes will be drilled into the firbricks with a 1/4 masonry bit, lead lag shields in the holes will hold the lag bolts fast ans securely anchor the plate. Stove pipe will then be secured to it using sheet metal screws.

[nissanneill]

Re: The best way to do a metal chimney?

rhollman

A 1/2 inch tall ring will be welded around the perimeter of the circle.

I would make this ring at least an inch high, and if you make it a snug fit on the bottom of your 'stove pipe', you should not need any screws in it. My 10' flue (3 sections high) was self standing before I put it through the roof of the new patio and even today has no screws in it.
Sure, secure the base to the bricks but by having a 1" tightish collar" you will be able to slide the smaller convaluted end into the ring easily as they are usually tapered and get tight as you push ot hammer it home.

Neill