Plugging the Chimney

[pastorryanhayden]

I'm the guy from another thread who built a brickwood oven and am trying to modify it. One of the suggestions was that I close off the chimney, add an entrance arch at 63% and put the chimney outside of the entrance arch.

I've built the arch and closed off the front of the oven, but I'm wondering about how to go about closing the chimney. Can I just put firebricks over the opening and have a a five inch square hole in the top-front of my oven that is four inches deep. That would be the easiest thing.

Alternatively, could I screw some kind of metal support to the ceiling of the oven and put bricks on top of that?

I tried mortaring in bricks but it doesn't look like they were going to hold so I knocked them out and now I have a five inch hole in the top of my oven.

I know these are totally newbie questions. Any help is really appreciated.

[Tscarborough]

Re: Plugging the Chimney

Since you have access to the top, I would place a form over the hole from the inside, brace it well, then pour a refractory concrete from the top to make a 4" thick plug. Break up some firebrick scraps into 3/8" and less gravel, mix it with your refractory cement at a ratio of about 2 parts aggregate to one of cement. Discard the dust from when you make the aggregate.

https://www.youtube.com/watch?v=CNcFwByeUzw

[pastorryanhayden]

Re: Plugging the Chimney

Tscarborough,
Thanks. I just ordered a small batch of castable refractory. I've got a wheelbarrow full of firebrick fragments.

[david s]

Re: Plugging the Chimney

You may need to grind some of the hole on the outer side a bit so your cast plug will be tapered. You wouldn't want the plug to fall in.

[pastorryanhayden]

Re: Plugging the Chimney

David,
Thanks for the tip. I'll take that into account.