# Almost finished my own Fume Hood



## kkmonte (Mar 17, 2013)

Hi guys, figured i'd post my fume hood that I made. I'm mainly processing fingers right now, and just wanted something to contain the HCL and Chlorine fumes and to exhaust them outside. Most of the work i'll be doing is mixing solutions and then i'll be closing the front door so i figure the smaller fan should keep a negative pressure with the door mostly closed. I live on a big piece of property and this is the back room of my barn, so exhausting the fumes outside is my primary goal. I'll probably build a small scrubber for Chlorine fumes in the future but for right now i'm excited to start using this. The bathroom exhaust fan I used has an entirely plastic housing, I figure I might have to replace the motor at some point, but it was pretty cheap so I thought i'd give it a shot. It does 120 CFM. Most of the time, i'm going to leave the exhaust fan running, it doesn't draw much power. I'm also going to drill an air hole in my work area (to serve as a drain in case I have an acid spill with a plastic container underneath as a catchbasin) and also to help eliminate fumes that build up in the lower storage area with my acids (i'll have my 5 gallon buckets of Copper Chloride, etc). I built a 2" lip across the front, i've caulked the entire inside and outside where any seams are. Plexiglass is 37" long X 24" wide (with 1/2" of it in each track on each side), i cut an 1/8" saw cut in the 2X4's with my table saw to act as a track for my plexiglass. I sprayed this groove with liquid silicone and it actually slides up and down quite nice. I have a small clamp that clamp to hold the plexiglass door open. All wood has had 2 coats of good ole fashioned oil based Kilz. (not shown in all pictures).

Any hints/tips are welcome.


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## Noxx (Mar 17, 2013)

I'm concerned that the bathroom exhaust fan won't last very long. The plastic housing will help though.


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## Smack (Mar 18, 2013)

All that stuff mounted on the inside, should be mounted on the outside. All metal objects in there will corrode, nails, screws, light sockets, exposed copper wire and the brass inside the outlet. Also you better at least triple that CFM.


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## goldsilverpro (Mar 29, 2013)

Standard rule. To keep the fumes out of your face, you need 100 CFM per square foot of opening.


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## Westerngs (Mar 29, 2013)

From experience, it is best to keep wood away from silver nitrate. It makes the wood extremely flammable so that just some heat will cause it to light on fire.

Had a very large fire many years ago due to silver cells sitting on wood benches.


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## kkmonte (Mar 29, 2013)

Smack said:


> All that stuff mounted on the inside, should be mounted on the outside. All metal objects in there will corrode, nails, screws, light sockets, exposed copper wire and the brass inside the outlet. Also you better at least triple that CFM.



I've covered all exposed metal objects (except the inside of the electrical outlet, I caulked the entire plastic electrical box inside and caulked the cover plate on. I think the screws and copper wires are protected) with silicone caulking. It's working great for me right now, i'm only processing fingers right now, I do about 2 lbs per month. Not planning on doing any silver nitrate, so that isn't an issue. And like I said before, I usually have the glass open, drop my items into whatever I need to do and then close the glass down and leave a 1" opening. That's only just over 1/3 of a SQ FT of opening, so 120CFM works great at keeping it a negative pressure in there.


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