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Looking for plans/schematics or an affordable fume hood

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Use the search function and use 4metals as the author, if I remember correctly he outlined a simple but effective hood and scrubber system some years back which if you are capable with tools and have the time was easy enough to construct.
 
Also do check if it's a fume hood or a fume cabinet that you are looking to make.
 

Very interesting. Do you have any idea if this could be done with a 5 gallon plastic water jug, or would the acid vapors dissolve it?
 
This was made with a 55 gallon drum and this funnel on top http://www.usplastic.com/catalog/item.aspx?sku=78112

A 4" PVC pipe goes to a 400 CFM blower.

The bottom contains spills nicely, and if you use a translucent white drum you can see inside much better as light passes through the wall. If you sacrifice a second drum and cut out a square about 2" bigger you can fashion a door that slides up and down to close off the hood.

Very economical, very effective.
 
4metals said:
This was made with a 55 gallon drum and this funnel on top http://www.usplastic.com/catalog/item.aspx?sku=78112

A 4" PVC pipe goes to a 400 CFM blower.

The bottom contains spills nicely, and if you use a translucent white drum you can see inside much better as light passes through the wall. If you sacrifice a second drum and cut out a square about 2" bigger you can fashion a door that slides up and down to close off the hood.

Very economical, very effective.

This is exactly what I was looking for! So simple and creative!

Can you possibly give me the finer details of this build? Also, I would be interested in adding a scrubber...

Is this a suitable blower? I need to understand further how these fans work, would the fumes not corrode it?
https://www.amazon.ca/Active-Air-400-Inline-6-Inch/dp/B00KWYJQYA
 
There are a few things you should notice about this drum hood that do not jump out at you but are important. First, the bottom of the opening needs to be about 4" off the bottom. The bottom should not have any drains or openings in it at this point. This allows the bottom of the drum to serve as a spill containment area.

The opening should be 2 feet wide by 2 feet high. That will allow you to use a 400 CFM blower.

After you cut the opening and acquire the funnel, place the funnel on top of the drum and cut out the top leaving the reinforcing rim intact. You want the funnel to sit on the top and then you will silicone it in place.

It is quite possible this will work without the funnel and by simply putting a 4" pipe out of the top but the funnel makes it more effective. The fumes you generate will rise up in the hood and the funnel tends to concentrate them and herd them into the exhaust duct.

Another change you can make is to add a sliding door to close off the hood. This is nice when you have a reaction going because by making the opening smaller the airflow through that opening increases. To do this you will need a second plastic drum which you will cut up for parts. First cut a pair of strips from the length of the drum about 6" wide and 3 feet long. These are mounted along the sides of the 2 foot opening. They need to be secured, preferably with plastic nuts and bolts so the door you will cut next slides up and down in the groove made between the body of the drum hood and the strip. By spacing the bolts in about 1" from the outside edge you will leave room for this to work effectively. (If you use metal bolts and nuts, a liberal dab of silicone is required to protect them from the fumes inside the hood.)

Next you need to cut the door from the spare drum. Measure the distance between the line of bolts you used to bolt on the strips on each side and cut a section about 1/2" less than this width. This is about 24" for the width of the hole plus about 8" for the door to be bigger than the opening and slide in the groove. The hood door should also be about 2 or 3" higher than the height of your opening.

You may notice when opening the door it hangs up on the bolts. This is because you didn't lift both sides at the same rate and it tilted. One easy way to overcome this is to cut strips about 2" wide and as long as your original strips and use them as spacer strips so the bolts cannot get in the way and the door slides along the smooth cut of the spacer strip. The spacer needs to be straight so using a table saw to cut the strips pays off nicely. It never fails that when you only have one hand to open the door with it will find one of those bolts.

To stop the door from closing all the way to the bottom (it is always good to leave at least a 1" air gap) add bolts that will stick out close to the bottom edge of the track you made for the door to slide in, one on each side is good. To keep the door open, slide the door in the track to the fully open position and drill a hole on one side that will allow you to slide in a pin to fit through the hole drilled in the track and be under the door, causing it to tilt slightly to one side and stay open as it cannot pass the pin. A door hinge pin works well for this and a length of string hanging it right where it will be used guarantees it will be there when you need it. To close the door simply lift the door, pull the pin and the door will lower.

Another point to consider, they make a translucent white drum that is more effective than the blue one in my photo because it allows light to penetrate in from a well lit room. Seeing what you're doing has its advantages!

As far as the blower you posted, I wouldn't use it. The fumes will get to it eventually. A scrubber will make it last longer because it will take the brunt of the chemistry that would corrode the blower but it will go eventually.

These hoods are cheap enough that a lot of small shops make multiples and have a row of them, all powered by one larger blower.
 
I should add before someone asks about the door. The door is not transparent so when it is down you cannot see in. I know some refiners who tried to use 1/8" plexiglass as the door. It is quite flexible and slides up and down but it doesn't stay clear for long. Since the drum is curved, the plexy rubs when it is lifted or lowered and before long it isn't clear. That is why I use the second drum to cut the door, plus it is curved just like the hood drum so it slides easier.

Everything in refining from the chemistry to the equipment is a trade-off. So an inexpensive hood ends up with an opaque door, you have to get over it. Obladi Oblada, life goes on.
 
4metals said:
I know some refiners who tried to use 1/8" plexiglass as the door. It is quite flexible and slides up and down but it doesn't stay clear for long. Since the drum is curved, the plexy rubs when it is lifted or lowered and before long it isn't clear. .

Plex is easy to bend, lay it over a curved object with the same radius you need, slowly heat with a heat gun. Move the gun around to evenly heat and to prevent burning/blistering the plex. It will soften and lay down over your template taking it's shape. Remove heat and let cool. I used S/S hinges on my plex door although sliding would be better for an adjustable opening.
 
Plex is easy to bend, lay it over a curved object with the same radius you need, slowly heat with a heat gun.

Would the drum you are using for a hood serve as the template for this bend or will the heat be too much for the drum to handle?

A clear window would be better.
 
Use a metal drum....the radius is the same. If you have an oven you can heat a sheet of polycarbonate up to just below the glass transition point. Once hot, lay it on the drum and strap it down somehow. Heat a little more with the heat gun and let it cool.

We used to thermoform prototype windshields in a similar manor, just using a glass windshield as the mold.


Sent from my iPhone using Tapatalk
 
I used to build a lot of my school projects from scrap plex from the local sign shop. Did them in the kitchen oven, only when mom wasn't home. Didn't hurt anything, but did stink a bit. :oops:
 
Just found myself two blue 55 gallon barrels. I'm very happy as I can now order that funnel, and begin building my fume hood/scrubber.

If anyone has time, I'm looking for a few links.

1) I need a link to the best "build a scrubber" tutorial here on the forum, or elsewhere. I want to better understand the process of cleaning fumes efficiently, and learn how to make one that will work with the barrel set up.

2) can someone send a link to a proper blower, one that has enough power and able to withstand the fumes?

I need a bit of direction to do this properly, your involvement would be as good as gold. ;)

Thanks everyone!
 
Damien said:
Just found myself two blue 55 gallon barrels. I'm very happy as I can now order that funnel, and begin building my fume hood/scrubber.

If anyone has time, I'm looking for a few links.

1) I need a link to the best "build a scrubber" tutorial here on the forum, or elsewhere. I want to better understand the process of cleaning fumes efficiently, and learn how to make one that will work with the barrel set up.

2) can someone send a link to a proper blower, one that has enough power and able to withstand the fumes?

I need a bit of direction to do this properly, your involvement would be as good as gold. ;)

Thanks everyone!
1: http://bfy.tw/9dGm

2, any squirrel cage fan should get you a good enough air movement for a barrel fume hood, so long as its not a pathetic weak one for a bathroom exhaust fan

Also, the search function at the top right (not the google one) is excellent when using it advanced.
Or, google.com and in the search bar type "site:www.goldrefiningforum.com scrubber build" (or something like that for the keywords, minus the quotes)
 
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