the hood in the front is 2 foot tall , the hole thing is 3 foot, and thats off the top of the table...im thinking it will let smoke out the front. i can always ad a pice to the front..

To answer you question, does smoke get into the room? Try opening a door or window to let an equal amount of air in that goes up the chimney. Go outside and look at the amount of smoke coming out of the chimney. That is the amount of air you need to bring into the room to replace what went up the chimney.

If you still get smoke, lay some metal up against the end first, then in front of the hood from the top of the hood down. You may want to close up the sides on the front some. Once you get no more smoke, problem solved.

You do have a chimney attached to the hood don't you? What size / diameter?

no im still making it , never been fired up, just thought some one might have one like this and could give me a hood hight off theres... it will have a 10 to 12 in. pipe...

Probably yes, look at all the room air it will suck in which will cut down on the chimney effect especially in the summer.

With a big enough and tall enough pipe, you don't even need a hood. This pic of the NCABANA shop at the NC State Fair shows the flames & smoke being sucked sideways and up, never seen it smokey inside myself.

i like the look of a hood , and i have seen working shops with hoods , so they got to work ....

Do not skrimp out on the diameter of the pipe! Or the height of the pipe. The exit of the pipe must be above the roof line. The taller the pipe the more velocity it works, but there are limits (laaws of physics).

Many old school people always had their chimneys 2 feet above the peaks in their roof. So, there must be something to that.




Carry on

I found this 'cone' at least 35 years ago in a junkyard and paid $15 for it. It's been through more moves than I care to remember and it's always functioned just fine with a 10'' pipe. I've thought about upgrading to a fancy side draft, but it ain't broke......Hoods can be used in a couple of ways that I wouldn't try with a SD, that is if I have a small painting project or acid etch to do I can do it under my hood (cold of course) and the fumes are wisked away no problem, otherwise they get done outside. 2' above the roof is minium and may be more as per code. Never scrimp on the length, but if it's too long it will tend to cool the smoke too much which can cause drawing problems.

macbruce that looks like a cne I made well over 30 yrs ago.I am sure it is not tho.I used the cone off of an OLD belt drive feed grinder.it had a 6" pipe
I unbolted the dust separator on top,flipped it over and hung it in the shop.no back or sides.just hanging above the forge

just an up date , it is letting smoke out in to the shop , think its the pipe length though, im useing 12 in. pipe but its only 1 foot over roof line, i got 3 foot more to add so ill get back with you all after i see if it helps...

Well that's bad news, I have been watching your shop build and was hoping for better results for you.
If that taller pipe doesn't do the trick for you close off about 25% of the bottom of that pipe with a ( temporary ) piece of sheet metal. Just to try and get some draw going. If it doesn't help you are out about five minutes of work and I will catch a lot of flak from my friends here at IFI. Oh but if it works........

Maybe your fire is not hot enough to cause the proper amount of updraft (convection) to draw smoke up hood and chimney.... Also if fire pot was closer to back wall it might help with convection....

Dale

Our shop is small and because of a number of things the diameter of the pipe was limited to 10 inches.... I think. It has been a number of years so we ended up installing a draft inducer in the pipe where it went through the second floor roof and there is literally no smoke in the shop. After the fire is hot we many times turn the fan off and it will draft ok but if it's windy the fan just keeps running.

It's not that bad. It's only when cold and only with green Cole.

I'm going to add of peace to the front of the forge and add another 3 feet of stack and will see what that does...

Man you never ask that question, its like a lady asking "do these pants make me look fat?"  :)

 

I use triple wall 8" id, on a side draft and don't have issues, draws well. BUT that is with triple wall all fuel stack that keeps those gasses hot till the exit.

I use a small 7" stack on my demo trailer, and it is a intergral side draft, and about 8' tall. Sucks up the smoke and it exits above head height so me and the viewers don't have to eat smoke:)

whell that did not work.... just as bad as it was at start up , when it gets hot it sucks small bits of ash of the floor though ! lol...

 

going to try to lower the hood down some next....

 

If you already have the wood stove going, that has probably already got the draft coming down the forge flue. Try lighting the forge first.

 

But it works good once it gets going? Preheat the forge flue.Try lighting a piece of newspaper and putting it up the pipe before you light the forge.

I always lite the wood stove first it gives me the coles I need to light the forge fire. So with the shop being hot that makes the Forge flue backdraft ? And I've always balled up newspaper and put it in the flue Per Glens advice . It's only coming out toward the verry edges of the forge hood . I'm almost certain if I lower it some it will draw just fine....

What would it take to tie the stove's piping into the forge's?  The extra piping in the shop would help radiate some heat into the shop for those cold winters and help move the forge's smoke up and out.

Yeah I thought about that..

Just a thought, is your shop closed up very tight with winter being here etc? I know if our furnace is running and I open a outside door I will get a blast of warm air as the furnace is an ols system and uses outside air source. If the forge is running in a tight room it might be possible it isn't having a free flow of air to the outside. Again just a thought.

yes my hood was to tall !

 

got it fixed , lowerd the hood down , now its smoke free ! YES !!!!

So...what are the final dimensions of the opening?
Phil

about 18 in. at the tallest...

We installed a Tjurland draft inducer..... if memory serves me right in the stack within the second story. It runs on 110v and we use it to start the draft. Once all is hot and working you can shut the fan off and it all works quite well. The box we built to house the fan at the roof penetration area has a temperature sensor in it so we can tell how the stack and box are at the roof. The readout for the sensor, blower control and fan control are all at the forge on the first floor.