Need Advice On Ventilation For Stick Welding In Shed

[ome]

Hi Guys,
I have been welding outside the last 4 months, now with the rain, need to move my practice sessions inside shed.
Here is what I am working with.
Lean -to shed -10' wide by 14' deep with welding table by one window on higher side, which is about 10' inside, with all walls covered with 1/4" cement board and alum flashing covering other interior spaces.
Only the ceiling is not covered.
Harbor freight ventilator:
3300 rpm, 1590 cfm hi, 1380 cfm low 1.4 amps
8 " but with flange is 9.75".
We have 8" alum flex pipe , and another window open, with window fan blowing in, across from window with vent pipe going out.
Two 10' tall doors , each 3' wide, usually closed or one door opened, depending on direction and intensity of rain.
I need some advice as to where to buy some adapters out of tin or ss, to connect the 8" flex alum pipe to the 8.25" neck just past the 9.75 flange on the exhaust port of the ventillator. Same is neede for the inflow side of the 8" to ventilator( both sides the same measurements)
And a sizeable hood (12" by 8") to pick up over my table when welding. All with the 8" flex alum pipe.
We set up a mock prototype with duct tape as joinery.
Worked ok, but some smoke escaped the 8" pipe hanging 12" over weld area.
What would work to be able to use clamps so is more permanent, but can be broken down easy if needed?
Where can I get these, or have them made.
I do not have the experience to even try to fabricate them.
Here is a pic,
Thank you in advance for any advice ,
Ome

 

[JimDawson]

I would just use the duct tape as the ''adapter'', duct tape is an all purpose adapter. Short of having something custom built at a sheet metal shop, it's the next best thing.

You could go to a restaurant supply and try to find a hood, but a range hood from the local big box store would work fine. An old top off a barbecue grill could be modified too. Time to get creative here. The big box store also has a bunch of sheet metal ducting parts, a stroll through the isles can get the creative juices flowing. That's what I do when I don't exactly know what I want to do on a project, just look at everything and think about how you might make it work for what you need.

 

[Franko]

I bet a galvanized trash can lid would make a good hood.

I'm guessing a hood might not be completely necessary. Your rig looks like it will move a lot of air and as long as you weld near it, it is going to catch the smoke.

Stick welding can be pretty sparky. It might be a good idea to put corrugated steel wainscot on the walls around your welding station.

 

[TomKro]

Ome:

I like the use of semi-rigid duct. Nice idea.

You may want to consider getting a wall mounted chimney thimble. I believe there are inexpensive ones up thru 8 inch pipe, so you could bolt the blower directly to it. If you go thru the wall, you'll need to cap the exhaust with some sort of metal exit louver, but I believe there are inexpensive ones available. If you put the thimble high on the wall, you can flip your ventilator upside down and hang it from the ceiling. That might shorten your pipe run and free up some floor space.

You should also consider using the window for a box fan to make sure you have fresh air to breathe. I'm no weld safety expert - caught my pants on fire once when I forgot to move an acetone soaked rag. Maybe others could advise you better.

TomKro

 

[ome]

G

 

[ome]

Thanks to all , jimdawson, Franko, and tomkrow,
Thanks for your advice, certainly gives me some ideas.
The sparks make me only burn 7018 and not 6010 5p+ inside.
That said, I will probably have to put a fan in the opp
Window and keep atleast one door open.
Thanks for the ideas.
Got to keep my practice up if I want to master stick and go on to tig.
Thanks again to all of you.
Ome

 

[brino]

Time to get creative here. The big box store also has a bunch of sheet metal ducting parts, a stroll through the isles can get the creative juices flowing. That's what I do when I don't exactly know what I want to do on a project, just look at everything and think about how you might make it work for what you need.

That's great advice Jim, I do that often. Even if this research doesn't help with the current project, I often find stuff usable for the next project.

I also get to confound the employees at the local hardware store. I guess most people go in needing a specific part or bolt, and I go in needing "a chuck of stainless about so big", or "a piece of plastic I can make something out of". (I have found multiple uses for hockey pucks, from vibration damping foot pads on my power hack-saw, to debris shields on the front axles of my truck, to a tapered cork to pressure test my radiator last week.)

-brino