here's a picture of the side draft forge hood I built for my forge a couple weeks ago it's like 32"wide 14" deep 48"tall with a six inch smoke shelf a slanting floor. the opening is 10x12 the stack is 10" dia, x ten feet tall i'm still playing with it ...I think I'm going to have to put a wall up around it to stop the air currents/

here's a picture of the side draft forge hood I built for my forge a couple weeks ago it's like 32"wide 14" deep 48"tall with a six inch smoke shelf a slanting floor. its made of 11 ga steel the opening is 10x12 the stack is 10" dia, x ten feet tall i'm still playing with it ...I think I'm going to have to put a wall up around it to stop the air currents.

heres the picture

I have a very similar one and put a 2" wide lip at the top of the arched opening. This tends to heat up quickly and help pull in the little ambient ribbons of smoke when the forge is cold or at idle.

I have a very similar one and put a 2" wide lip at the top of the arched opening. This tends to heat up quickly and help pull in the little ambient ribbons of smoke when the forge is cold or at idle.

mine has a 2" lip also just can't see it the photo I'm still messing with the hight and have problem when the wind is out of the west I might have to enclose the space

Take the bricks out from under the hood and put the hood as close to the fire as possible without hindering your access to the fire. This should allow it to draw better.

I also put some fire bricks inside the hood - 3 on each side but not blocking the opening. They heat up and help it draft.

I just raised it up 2 inches to see how it would draw as the smoke seemed to rise to that higth. I also loaded about 5 bricks inside on each side and it does seem to make it draw better . I was thinking of getting some of the thin fire bricks made for stove liners over at tractor supply and lining the floor

One other thing to consider is the size of the opening. I was always told that the area of the opening should not be larger than the area of the flue. A ten inch stack would have an area of roughly 78.5 square inches. The ten by twelve inch opening you have is 120 square inches. So your opening is one and a half times the size of the flue.

When I built my side draft, I made the opening eight by nine inches since my existing stack was a ten inch round. It draws very well even when starting a fresh fire with a cold flue.

before I raised it th other day I had two inch thick fire bricks on the floor which made the opening more or less 10x10 seemed to work ok. it was just the start up of the fire was too much smoke coming back at me and not going up the stack thats why I raised it to see if it would work better
like I said I'm still playing with it.

Preheat the stack with a couple of sheets of flaming newspaper. Assemble the materials for the fire and just before you light the fire, put a couple more sheets of flaming newspaper near the stack to get the draft going. Light the fire and it should suck up the smoke.

More stack height always works wonders. :)

I'll give that a try

well I got one of my boys over to help me lift the hood and move the bricks and set the hood right down on the edge of the fire box...what can I say "It Sucks" Now if I just had some of the tile they put on the space shuttle to put on the outside of the hood so it dosen't radiate heat back at me I'ed be set.

Put a piece of sheet metal (thin tin) say a couple of inches away from the hood surface. Leave a inch or so of free space at the bottom of the sheet metal. This will slow down the radiant heat.