Well basically , at the front of your oven you want to drop the smoke down and thus it will want to go up again QUICKLY thus the "draw" from you chimney will help that and the assumption then is that you end up with a clean fron of oven as no smoke comes out the front ++++ that smoke "pocket" holds heat rather then letting it go straight away thus giving you oven a more effecient use of the wood. I think thats the concept?
so here are some images for you to look at what i did, there are millions of ways but you might get the basics.
here's the concept, you have your front bricks of the oven but you leave the roof short so you can place slanted bricks to create the "drop" at the oven door. allow for mortar depth.
you can see here i just cut the bricks with a angle grinder, i only have a few to cut. To work out the angle use pythagoras theorem, http://en.wikipedia.org/wiki/Pythagorean_theorem , you will need to use it in the "negative" spaces not the brick, meaning it is used to work out the cut-out piece not the end brick.This is what it looked like before creating the drop, that small angled brick on either side is actually a 1/3rd of a brick, the reason is simply to use as much of the space i had available
I videod this and will put it on youtube asap, then insert the link here:
here's the pre-drop mortaring the bricks prep, i have 2 small arch supports on either side.
here i have put the first arch bricks in and started the drop angled bricks, using fondue.
a more front view for you.
I found the mortar dries REALLY quick so those arch bricks held themselves up within 10 minutes !!!
a more front view for you.
I found the mortar dries REALLY quick so those arch bricks held themselves up within 10 minutes !!!
heres the 5 middle drop bricks, you can see i'll need to place some front bricks and the last left/right-arch brick in, these bricks will need to be cut to order.
The inside (not cleaned up) there are better shots coming later on in this blog as I close up the oven.