Making a home made fume a Hood

java · Consumer

Here is a thread from the Hive archives which may give some suggestions as to how to procceed.....java
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nitrous351
(Stranger)
05-22-03 04:04
No 434714
Plans for a homemade fume hood? Bookmark

This is my first post ever, so please don't flame me! I had a dream the other day about a homemade fume hood. In my dream, this is what I did:
Got a 25 gallon aquarium from a transmission shop (don't ask) for free... got a 25cm bathroom exhaust fan from a home salvage store ($5)... a length of dryer hose (long enough to go from my "work-station" to outside) ($10)... some RTV sealant from my garage (made of silicon, about $5 at a auto parts store)... roll of duct tape ($2)
Ok, I used glass cutters to cut a hole in the bottom of the aquarium. The hole was cut to the mounting dimensions of the exhaust fan (Cutting glass is VERY tricky...take your time!)I mounted the fan using the RTV sealant.... be sure of a good seal... don't want any leaks. I then duct taped the hose to the back of the exhast fan, and ran the other end of the hose to outside. I suspended the aquarium from the ceiling using hooks that I screwed in. All you have to do now is wire up the fan (Actually wire it BEFORE you hang the setup). If you don't know how to wire something into a circuit, please ask a knowledgable friend to help you! I know it's a crude setup, but it seems to work ok. I'm not sure if there will be any problems with corrosion of my fan, hose, etc... I plan to check that after every use. If something needs replacing, it will bee cheap. Always bee safe. If this hood ends up not working well in my next dream, I'll bee sure to re-post. If anyone sees any kind of problem with this design, please let me know (I don't want to die from some stupid mistake I didn't think about). Peace
Dyslexics of the world untie!

SpicyBrown
(Hive Bee)
05-22-03 16:42
No 434820
Re: got a 25cm bathroom exhaust fan from a... Bookmark

got a 25cm bathroom exhaust fan from a home salvage store ($5).......
If anyone sees any kind of problem with this design, please let me know (I don't want to die from some stupid mistake I didn't think about). Peace

Well for one, if you ever will be working with anything flammable (and you probably will) you want to have a sparkless or otherwise explosion-proof exhaust fan. That bathroom fan is probably not sparkless. The brushes on the electric fan motors of any normal fan occaisionally give off sparks, which could be quite bad for you.

-SpicyBrown

The_Fog
(Hive Bee)
05-23-03 00:01
No 434909
your dream.... Bookmark

Your dream sounds like my first nightmare. As stated above that fan WILL spark. No question. youve been lucky. If youre gonna hang an aquarium upside down it must bee something you have hidden? extra room etc? anywayz, if it is something you need to put away when youre done, what you have is going to make that easier. However, what you NEED is a fan that has the motor isolated from the air beeing moved ie:squirrel cage fan (use google) little bigger and heavier but its power makes up for that. Your vent tube needs to bee chem resistant rubber or plastic.

think exhaust tube in a mechanics shop to pipe the car exhaust outside. good luck.
bubble bubble baby.

moo
(Hive Bee)
05-23-03 00:54
No 434920
UTFSE! I typed the words fume hood motor ... Bookmark

UTFSE! I typed the words fume hood motor sparkless to TFSE and wht did I get? Post 90798 (Bozakium: "Re: DIY Fume Hood", Chemicals & Equipment), now do it yourself and see. Learn to UTFSE and you will suddenly learn a lot more. With search terms motor spark you will get even more hits to go through. Boring? Hell no, there are GEMS hidden in the Hive!
fear fear hate hate

tranceport
(Hive Bee)
05-24-03 02:08
No 435134
Ok.. Bookmark

But moo, come on... Of all the newbee's, this isnt the one to jump out and say that too. He is trying. I am sure if he knew about motors, and how they work, he might have picked that one out. The idea of sparks never even crossed his mind, and why search for an idea if it seems easy enough? I think you forget the annoyance of newbess is to sit and wait for you to do it for them. I admire a bit of the grab the bull by the horns approach. It isnt safe to approach chemistry like that in all respects, but he did ask if you saw anything he missed before distilling those petro chems. Also I dont see the possibility of searching fume hood brushless sparks <-- Again, this wasnt taken into account, nor is warning made organic chem, or buy shopping for the crap. You forget, this is clandestine, and not once, in any of my chem classes, or my acquisistions of real gear, did they mention, this is a fumeless hood, and this one, can only be used with non flammable materials.

I think its rather a nice try at first post and allow me to welcome you here. You missed the whole sparks and flammable gaseous vapors thingy, wink but otherwise good idea.

tranceport
05-24-03 02:10
Now nitrous...
(Rated as: insignificant) Bookmark

moo
(Hive Bee)
05-24-03 06:48
No 435167
Yes, point taken. I think I wasn't reacting to Bookmark

Yes, point taken. I think I wasn't reacting to the post nitrous made but to the posts after it, knowing that there are many good solutions to the problem waiting to be found in the archives. Of course, it is good that people really try to come up with their own ideas, that's the way innovations are made. But then again, we are standing on the shoulders of giants, which in these parts means TFSE with all its info. The best way is first to UTFSE and read, after which some of the problems that have been bothering are resolved, after which there is ground for new innovations. I'd just like the newbees to understand that if they want to get something really good, the have no other choice than to find out about what has been discussed over the years.

And nitrous, keep going! I wouldn't make my fume hood out of glass. Consider the possibility of explosions and all that.
fear fear hate hate

Organikum
(Hive Addict)
05-24-03 09:59
No 435191
"bilge fan" is what you´re after Bookmark

The fucking fan needed in fumehoods is called "bilge fan" and is used in boats. It is to get all over for not very much money and is made exactly for this: evacuating possibly corrosive and explosive gaseous mixes.

Regards to notfman who did dig this up long time ago.

Everything else whats not explicitely marked as "explosion proof" will either lead to an explosion or the bearings will corrode.

nitrous351
(Stranger)
05-24-03 17:25
No 435283
Thanks for the advice Bookmark

Wow, I totally didn't think about the sparks from the motor... it's a good thing I haven't tested it with chems yet... I tested it by boiling water and letting the vapor get sucked out. I will get one of those squirrel cage motors, or alter my design.
< now all you need to ask is what's the fastest way to cook dope...> (paraphrase) Whoever said that, I don't know what that's supposed to mean, but if it was condescending, you have another thing coming. I am a college educated bee who has a passion for chemistry. I also like to have fun.. I don't dream about syntheses so I can "cook up dope" and sell it on the street corner to 12 yr old kids to make a few bucks. I dream about syntheses because I'm tired of paying outrageous prices for "dope" of unknown quality. Since I have the knowledge, why not dream myself?
D.A.R.E. = Drugs Are Really Exciting

wyndowlicker
(tourbee)
05-28-03 18:21
No 436204
Explosion free motors Bookmark

Hey now,

Yes indeed if you take a look around those fans arent cheap even used.Upwards to a grand.The ones recomended for fume hoods.So your saying that they can bee had for much cheeper?Great.What about when working with a professional fume hood?Flip a link for a good fan if ya got em'tongueAlso remember when you were a newbee it wasnt easy.tongue
And the bees make honey in the lions head.-GD

jose
(Newbee)
06-01-03 05:11
No 436965
think boats Bookmark

skip back a bit in the posts
those boat blower fans really move air, are sparkless, and cheap as fuck
remember to use a 110 to 12v converter

raffike
(Hive Addict)
06-01-03 08:07
No 436979
I don't know if it's just me but i've never... Bookmark

I don't know if it's just me but i've never seen a fan motor with brushes,3 phased or 1 phased.
For those about to synth,we salute you

calcium
(Hive Bee)
06-01-03 11:35
No 437042
there are brushes and there are brushes Bookmark

Raffike, knowing that English isn't your primary language, I wonder if you realize that we what we call a "brush" in an electric motor is a carbon block shaped to fit the motor's rotor, not literally a brush with bristles. No flaming or even sparks (bad pun) intended, just clarification. Lots of fans have motors with brushes. I'll shut up now...

raffike
(Hive Addict)
06-01-03 11:45
No 437043
Yes,we refer to these carbon thingies as ... Bookmark

Yes,we refer to these carbon thingies as brushes too,there are 2 of em in motor if all.But because these brushes wear,they only use them when absolutely needed,like in electric power drills and stuff where motors must be powerful yet light.
For those about to synth,we salute you

IndoleAmine · Dreamreader Deluxe

Hm - what about placing the exhaust fan at the inlet of a piece of said dryer hose, leading TO the fumehood? So that the exhaust fan blows air through the dryer hose, through the fume hood and then (again through dryer hose) to the outside?

One could even construct a fumehood which is blowing air from the lower front to the upper rear, through several small pipes, to ensure a continuous and even air flow inside the fumehood - blowing always away from the opening, should you eventually have to work inside, which is unavoidable....

...but the main advantage: since the air passes the fan motor BEFORE being saturated with eventually flammable vapors, you can use a cheap exhaust fan...

(the best material would probably be plexiglass/acryl plastics, since they can be glued together gastight with special glue, and they are very light materials, further can hardly break. Maybe not very chemical-resistant, but this is not the main issue with homemade fumehoods I would say)

i_a

nubee · Master Archiver

there's a good basic guide in the book available for dl called:

"how to set up and operate a clandestine drug laboratory"

nyarlothotep · Thu Mar 31, 2005 10:11 am

The gasses in a traditional fume hood (clandestine or otherwise) still pass UNFILTERED to the open air.....and as has been seen, most active labs have been nailed due to "odd smells" and the like.

SWIN's question is.....where do we incorporate a trap mechanism, preferably changeable with solvent for the reaction at hand, without causing a possible backup of dangerous/explosive/smelly fumes....
Seems to SWIN that there was a beautiful setup posted by a Hive Bee in the long long ago......but in SWIN's infinite lack of foresight, that thread has been lost to him. Mad

Ideas would bee welcome.

java · Consumer

The book that nubee mentioned,The Construction And Operation Of Clandestine Drug Laboratories , is in the e-book section of References......java

icecool · Insistent Chemist

SWIM is planning on making a fume hood.
He will make pictures and post them.
He already found a 12cm diameter sparkless ventilator which moves 180 m3 per hour.
And he will buy plexiglass plates which are quite thick and glue these to eachother to form a box with a door on the front but a kind of a bucket on the bottom.
So if something brakes it will not flow out of the fumehood but will remain in there.
The bottom will be porcelain on top of the plexiglass.
And there will of course be a hose leading outside.

IndoleAmine · Dreamreader Deluxe

Sounds nice. Maybe you could even epoxy one or two big, thick-walled and huge rubber glove into appropriate hole(s), so you have kind of a glove box....
(just an idea)

And please, please make sure your fan is really sparkless; since you will be blowing shitloads of ether fumes through it probably... (180 m3/h sounds like a good one though!)

And another idea: maybe an air filter filled with active carbon (like the ones used by cannabis growers to eliminate the smell) would help to at least reduce the smelly, detectable vapors? And active charcoal is cheap, so it could be replaced very often...

i_a

nyarlothotep · Sun Apr 03, 2005 9:04 pm

SWIN was thinking that, second in line to an appropriate solvent trap (solvent of course replaceable) would do the trick.
Just gotta rig a decent hookup/splashguard so that he can change the solvent fairly easily and not have to worry about huge bits of it blowing thru the afterwards portion of the setup.....
Thank goodness for PVC. Cheap, (relatively) non reactive.....AND pre-molded! Twisted Evil

IndoleAmine · Dreamreader Deluxe

icecool · Insistent Chemist

Have been thinkings some more about the fume-hood.
It will be a plexiglass box as I sayd before.
The ventilator costs 17 euro by the way.
So it isn't that much.
And it is really sparkless it works with little balls don't know how to call it where it turns around on.
And I will also make some ceramic plates in the bottom and glue them and put some cement between them like a floor in the kitchen.
So it can withstand some heat etc that falls on the "floor" of the fume-hood.
I'm not planning to make a huge one since it is for in my bedroom (I know I know you should actually not do anything in your bedroom at all...)
And the exhaust tube will go out of a window on the 3th floor of a house so before it reaches the street no one will smell it, and if I notice it does I'll put a filter between it but it is absolutely not necesarry quite sure about that.
When I've got more time in the coming days I'll start buying the material.

java · Consumer

Ok SWIM has made fume hoods both the type framed with plywood and on the inside with fire proof sheet rock with a pole type fan mounted on the roof for sucktion and a small blower fan below the bench where the fume hood sits to create an upward flow. The opening is covered with clear plexyglass mounted on a rail for sliding and with some holes on on the reiling channel to hold the plsxiglass up , also counter weights can be put in between the hollow of the outside framing and the sheet rock, much like the old windows used to have in order to stay up.

SWIM has also made the same type of bench mounted fume hoods out of sheets of polypropolyne and welded with spaghetti type material and a special gun that melts the spaghetti plastic and bonds the polypropolyne together. The same type of pole type blower mounted on the roof and a smaller fan put below the bench with some slit acoss near the opening to create an upward flow . One can mount lights covered with glass covering similar to marine applications to avoid moisture from entering and all plug ins and switches remain on the outside of the hood to avoid corrosion. the opening were all the cables come into the hood should be through a hole that is then covered with foam urethane to avoid any leaks.

This type of hood works fine and it can be made as large as one needs it with the same parameters kept in mind. A good suction from a pole type fan mounted at the roof , and a fan below the counter to create and maintain the upward flow.

.....................java

icecool · Insistent Chemist

Wouldn't a single 180 m3/h fan be enough that sucks air out of the fumehood, so without the upwards stream (which will be there a little bit but not as much as when you actually put a a fan in the bottom)
When the fumehood will be like 1m3 maximal.
It will refresh the air every 20 seconds...

java · Consumer

As far as Air flow Dynamics you will have to check out the books recommended, or try out your system and light a small fire of dry grass inside with the opening closed and then opened, to see if your fan will do it for you, almost have to adjust for your particular volume in your hood........java

IndoleAmine · Dreamreader Deluxe

My stomach tells me that if a fan can really move 180m3/h, then it will probably make someting resembling a medium taifun inside of that 1 m3 fumehood - no need to worry about air replacement rates with such an overkill exhaust fan IMO... Laughing

(maybe you could regulate the exhaust speed a bit, maybe with one of those room light dimmers or something similar? Then only for critical reactions, you could secure everything with cable and wire, and put the exhaust fan up to full speed...)

i_a

icecool · Insistent Chemist

Did some more maths and I calculated that my fumehood will be 1meter x 0,5 meter x 0,5 meter.
So that is 0,25 m3 so it will suck all the fumes out of the fumehood in 5 seconds lol Laughing

I also want to put light inside but I don't know yet if that will make sparks, or a little TL light in there, I know that in professional fume hoods there is a plexiglass plate where the TL light is behind.
There will also be a piece of plexiglass that can move up and down.
After some more considering I decided to replace the door idea for the up and down mechanism just have to find the proper materials to build it with.
And the walls are 4mm thich BTW and that is quite strong though.
There are also aluminium strips on every side of the cubic.
Like with a flightcase of a DJ.