i need an affordable and safe fume hood design for my garage lab

[skinny]

i want to refine as a hobby and means to make small pocket change i have a material source and some money for the material. my plan is to buy a few ozs of gold and some sterling silver and refine and sell rinse and repeat to gain experience make mistakes and learn. ill admit i can use a crash course in chemistry but i have some specific questions about a suitable fume hood design because i did not think that part through very well.

first, i want to build my own workspace chamber out of polycarbonate and mdf material from my local home depot i got 3mm thick poly sheets ill probably have to get bigger ones though. i want my workspace to be about 2 and a half feet deep and 4 feet wide and 2 and a half feet tall. there will be 3 holes in this box 1 6 inch hole for ducting or fan and 2 1 inch holes for wires to pass through raised above the working surface area incase of spill overs. the poly carb would be the front wall of the box to see through while my hands reach into box from the opening under the poly carb sheet. is this box design acceptable before i proceed?

next the air pressure design, i saw some things i didnt understand and am hoping to make sense of. putting the blower directly inline leads to corrosion so i want to avoid this. i saw something called a venturi? what is this and how can i use it to protect my air blower?

lastly filtration.. i see alot about scrubbers and different solutions and alot of stuff i dont understand what do i really need to know for small scale hobbiest is it necissary and in dumb mans terms how can i build one? my original plan was to use a carbon filter for a grow tent at the top of my fume hood ducted to an inline fan than ducted to a merv filter box and then ducted to my roof. can you tell me if this would be efficient? i have a second inline fan i can add to increase cfms but this would be alot cheaper than building a scrubber

so just to recap my current design for a fume hood is an mdf rectangular box with a clear polycarbonate front. a light will be mounted at the top a 6 inch inline carbon filter will hang from the top of the box and be ducted out the side of the box the filter will be connected to a venturi duct piece where the left tube will go to my first inline duct fan and an inline merv filter box out the top of the venturi will be another inline duct fan to add pressure and push the air out of my roof 15 plus feet above the ground.

what can i adapt here to be most effiecient and most budget friendly im not a huge business i wont become a huge business i am a hobbiest not a scientist


additional comments and questions: ive found fairly cheap air scrubbers on amazon would these work? and how can i integrate it in to my plans? im assuming i would replace one of the inline fans with the scrubber can anyone draw this out for me? i also want to use pvc pipe instead of ducting ill be using 6 inch has anyone done this before

 

[Xing]

hi, would you want order from China? is there details? do you need install? or install by yourself?

 

[skinny]

hi, would you want order from China? is there details? do you need install? or install by yourself?

id prefer not to if i can avoid it ill be installing and fabricating myself i cant afford a professional or prebuilt fume hood

 

[skinny]

hi, would you want order from China? is there details? do you need install? or install by yourself?

my biggest question is for 2 or 3 ozs at a time will a carbon filter and air scrubber from amazon be good enough to dilute and expel the fumes out my roof or am i gonna get someone hurt

 

[Xing]

maybe it is enough, if you only do some small test, if you are not sure, it need to adsorpt the fume with NaOH solution.

 

[Master Nater]

https://goldrefiningforum.com/threa...t-hoods-and-fume-scrubbers.34601/#post-373037

 

[skinny]

maybe it is enough, if you only do some small test, if you are not sure, it need to adsorpt the fume with NaOH solution.

your saying if it isnt enough i need to build a chemical scrubber with liquid lye solution? im trying to comprehend i dont know how to engineer something capable of what i need here. i want to refine karat gold and sterling silver my only hangup is what to do with the fumes for the reaction so i can safely expell them from my roof. from point a being the fume hood to point b being the roof how do i get there? can you make me a diagram using 6 in pvc for the duct material and the filters/blowers/scrubbers of choice? and by small amounts i am talking 3 or 4 ozs over a week of gold and 100 ozs a week of sterling
i want to do something like the second diagram i posted but with an air scrubber instead of an inline fan and carbon filter on top of the box

 

[skinny]

https://goldrefiningforum.com/threa...t-hoods-and-fume-scrubbers.34601/#post-373037

i looked through that thread and i think i understand more than before i did but still have some questions. is there a threshold for when a chemical or gas scrubber is necessary vs when carbon and hepa filters and air flow/mixing are enough and when is that? if a chemical scrubber is necessary how large of one should i create and is there a good template for adapting it to my fume hood

 

[skinny]

https://goldrefiningforum.com/threa...t-hoods-and-fume-scrubbers.34601/#post-373037

i drew up a little diagram with an air scrubber in place of the outer top carbon filter and blower but now i see the problem the scrubber never cleans the air from the box. what if i mounted the scrubber on top of the box connect the inline merv filter box to it then have my venturi joint with a booster fan on the other end pushing the air up and out the roof. thats double hepa filters and dual carbon filters and air pressure i can do another diagram if it helps to explain

 

[Master Nater]

i looked through that thread and i think i understand more than before i did but still have some questions. is there a threshold for when a chemical or gas scrubber is necessary vs when carbon and hepa filters and air flow/mixing are enough and when is that? if a chemical scrubber is necessary how large of one should i create and is there a good template for adapting it to my fume hood

whether you are required to run a scrubber or not will depend upon your local laws as to the volume of chemicals you go through before you are required to have a scrubber. some of the larger commercial guys on here will be able to answer these questions better for you. i'm just a hobbyist, and do not run a scrubber, as i am not required to with the little amount of chemicals i go through. give this thread a little time. i'm sure there are a couple of guys who will either answer your questions, or let you know where to look for your answers. good luck.

 

[Master Nater]

i drew up a little diagram with an air scrubber in place of the outer top carbon filter and blower but now i see the problem the scrubber never cleans the air from the box. what if i mounted the scrubber on top of the box connect the inline merv filter box to it then have my venturi joint with a booster fan on the other end pushing the air up and out the roof. thats double hepa filters and dual carbon filters and air pressure i can do another diagram if it helps to explain

i would be careful with carbon filters. introducing carbon to the chemicals we work with, could potentially make explosive compounds. again, best be patient, and speak with the commercial guys.

 

[AuggieDog]

i want to refine as a hobby and means to make small pocket change i have a material source and some money for the material. my plan is to buy a few ozs of gold and some sterling silver and refine and sell rinse and repeat to gain experience make mistakes and learn. ill admit i can use a crash course in chemistry but i have some specific questions about a suitable fume hood design because i did not think that part through very well.

first, i want to build my own workspace chamber out of polycarbonate and mdf material from my local home depot i got 3mm thick poly sheets ill probably have to get bigger ones though. i want my workspace to be about 2 and a half feet deep and 4 feet wide and 2 and a half feet tall. there will be 3 holes in this box 1 6 inch hole for ducting or fan and 2 1 inch holes for wires to pass through raised above the working surface area incase of spill overs. the poly carb would be the front wall of the box to see through while my hands reach into box from the opening under the poly carb sheet. is this box design acceptable before i proceed?

next the air pressure design, i saw some things i didnt understand and am hoping to make sense of. putting the blower directly inline leads to corrosion so i want to avoid this. i saw something called a venturi? what is this and how can i use it to protect my air blower?

lastly filtration.. i see alot about scrubbers and different solutions and alot of stuff i dont understand what do i really need to know for small scale hobbiest is it necissary and in dumb mans terms how can i build one? my original plan was to use a carbon filter for a grow tent at the top of my fume hood ducted to an inline fan than ducted to a merv filter box and then ducted to my roof. can you tell me if this would be efficient? i have a second inline fan i can add to increase cfms but this would be alot cheaper than building a scrubber

so just to recap my current design for a fume hood is an mdf rectangular box with a clear polycarbonate front. a light will be mounted at the top a 6 inch inline carbon filter will hang from the top of the box and be ducted out the side of the box the filter will be connected to a venturi duct piece where the left tube will go to my first inline duct fan and an inline merv filter box out the top of the venturi will be another inline duct fan to add pressure and push the air out of my roof 15 plus feet above the ground.

what can i adapt here to be most effiecient and most budget friendly im not a huge business i wont become a huge business i am a hobbiest not a scientist


additional comments and questions: ive found fairly cheap air scrubbers on amazon would these work? and how can i integrate it in to my plans? im assuming i would replace one of the inline fans with the scrubber can anyone draw this out for me? i also want to use pvc pipe instead of ducting ill be using 6 inch has anyone done this before

Use melamine and you'll thank yourself later. Melamine is actually resistant to the chemistry (it will stain but it won't break down) and it will save you from having to paint. Use whole silicone caulking and it withstands the harsh chemicals. Also, I built my hood with just 2 sheets of melamine and 2x3's. Get some melamine from a lumber supplier instead of Home depot or Lowes and the quality is much better! It was also cheaper I paid $40 a sheet just a couple of months ago. The polycarbonate window was the most costly item on my budget.
View attachment 63445

 

[AuggieDog]

i drew up a little diagram with an air scrubber in place of the outer top carbon filter and blower but now i see the problem the scrubber never cleans the air from the box. what if i mounted the scrubber on top of the box connect the inline merv filter box to it then have my venturi joint with a booster fan on the other end pushing the air up and out the roof. thats double hepa filters and dual carbon filters and air pressure i can do another diagram if it helps to explain

You could run a scrubber like the one I use (see my fume hood photo) and run it outside the hood if necessary.

 

[AuggieDog]

I use a 4in inline blower just like the one pictured below. It is attached directly to the top of my hood. These are $30 and move a decent amount of air. I also made it so it is easy to replace when it eventually fails. But I also run a scrubber for most work, meaning the blower is just there to capture fugitive fumes so it will last longer. I was going the more complex route you are going and I believe I simplified things with my hood design and the scrubber design (scrubber mostly due to 4Metals help and ideas).

 

[4metals]

An easy and sturdy solution is use an IBC container. They are available used for less than you will spend for your polycarbonate mdf stock.

Using an IBC is suggested and explained in this thread