DIY - Build a Carbon Scrubber For Dummies!

Here's what you'll need:

Tools:
Fat flat head screw driver (For Clamp Tightening)
Scissors (Preferrably Tin Snips if you have them or some tough scissors)

Parts:
Casa Depot-
1 - 4" Duct Cap $2
1 - 6" Duct Cap $2
1 - 4" Duct Collar $4
1 - 6" Duct Reducer $6
2 - 4" Hose Clamps $2
2 - 6" Hose Clamps $2
1 - Roll Duct Tape $3

Small roll of welded steel mesh (few sq. yards) - Firm preferrably. Not too stretchy. I used the stretchy soft stuff at first which works only if you pack the carbon in and use a lot of batting on the ends. It's ok but will sag. It doesn't keep its shape as well as the harder stuff. $6-$10

[Depending on how you will connect your fan, you may also want another reducer thats the same size of your fan and will connect to your reducer on the filter.]

Wallyworld-
Batting - Small Roll Blanket Style Not Clumped Preferrably $3
2 Pair Panty Hose (Clearance!) $2
3 18oz Cartons of Super Activated Carbon *@ Pet Store Too $15
(Or do like me and buy in bulk online. I found a guy on eBay selling 10lbs. of carbon for $10. Can't beat that! Although shipping was like $8-10 too but still a smokin hot deal.)

To figure out the size filter you will need for your fan, use this formula:
[If you need a larger diameter filter than listed in the tutorial, then you need to upgrade the duct sizes in the list and update the instructions.] Also keep in mind that if you're running some ghetto fan, expect ghetto results. Spend some decent money on your fan and it will perform. Some cheaper fans will give inflated figures too as to what the true CFM ratings are. My sig has a link for great pricing on vortex fans. I'm using the 4" 175CFM.

D = Diamter of Filter Inner Core (Inches)
H = Filter's Height (Inches)
I = Inner Core Surface Area Square Inch

CFM D H I
150 4 9 113
200 4 12 151
275 6 12 226
375 6 16 302
400 6 24 603
550 8 24 603
650 10 24 754

See the relation there?
Just take the CFM of your fan and choose the diamater of core you want and divide it accordingly. For example: I have 175 CFM and intend to use a 4" Diameter core. So I can look at the list above and figure;
150(CFM) divide 9(H) = 16.6 (Approximately)
Then I can take my 175(CFM Fan) and divide it by 16.6 to get 10.5". Therefore, my 175 cfm fan with a 4" Diameter would need a core height of 10.5".

[I found this formula somewhere online I can't remember. It's legit though.]

And so on... Just remember to be careful when your cutting the length of your core. It's important that the size is accurate or the filter won't work properly. If anything, you want to overshoot the height of your core by about a half inch at most. (I.e. I needed a 10.5" Height, so if there was a problem, I would want to make sure that my core is at least 10.5" to 11".) If you don't do this correctly you get a nice little backdraft and you filter nothing - like i did the hard way the first time lol. Filter the air - don't blow it around. Enjoy!



Ok step 1:
Take out your roll of steel mesh and measure the amount you will need. Make sure to use the formula above. Once you have the height of the core, just start snippin' away. I also like to use the same direction as the roll was in so it's easier to work with. [I have a 4" 175CFM Vortex fan so I built my filter core 10.5" Long.]


Step 2:
To measure the amount you will need, start rolling the piece you cut off around the 4" duct cap. Make sure to overlap by approximately 1-1.5". Or of course you can just measure it.


Step 3:
Once you have the size you need, go back and do one of two things. Either carefully snip off the long sharp edges or if you have a grinder, just grind them away. I have a grinder, but the snips were more accessible so I didn't bother. Here's a pic showing the difference. Get as close as you can - more details about this later.


Step 4:
Now make sure to have both the 4" duct collar, cap, and 4" hose clamps available.

Once you've smoothed out the mesh, begin wrapping it around the duct cap again and once you have it lined up straight, attach the 4" Hose clamp and tighten it down good. Make sure it's very tight, but don't get carried away and make it start bending. We want longevity, not overkill.


Step 5:
Now on to this little contraption which is going to be the core of our filter, add the 4" duct collar to the opposite end. Tighten the mesh and then attach the hose clamp just as it was done previously on the duct cap. You should end up with something that looks like the picture below.


Step 6:
Now unless your perfect, you likely ended up with this goofy looking part sticking out on the mesh. What I did is took some spare wire lying around (which you likely have too ) and stiched it down to the main piece. This is what it looked like when I was through.


Step 7:
Ok now open up a package of the leggings. We will be just cutting off the legs and the new 'socks' will act as a pre-filter. Depending on what type of leggings you got, you may or may not have a separate seam that attaches the panty part to the legs. If it's there, make sure to cut on the side of the panty and not the side of the legging. This will help ensure the end of the 'sock' doesn't unravel. Here are a couple examples for you:


Step 8:
Now we're going to make something that looks very familiar to most of us. A condom! No - kidding, but seriously I can't stop thinking that it looks like one. Take one of the socks from the open end and start rolling it. If you need help, please get in touch with the nearest female you know on how to do this. It's really not complicated. Just the opposite of wrapping yourself up.

Also, repeat this step with the second legging.

Step 9:
Now your going to take your 'sock condom' and roll it up and over the filter core. The closed side of the sock will end up on the same side as the duct cap. Also be sure to roll the sock only up to the point of the collar. Repeat this with the second legging so you have two layers of sock. It should look something like this when your through:


You'll find out quickly why it was so important to smoothe out the edges of the mesh because it will catch and cause the leggings to run like a marathon. SO BE CAREFUL!

Step 10:
Next we'll be taking the 6" to 4" reducer out and connecting it to the 4" duct collar.

Once it's in there securely, flip it over and we will then duct tape the collar to the reducer as shown below:

To ensure it's taped securely you can tape one part on the inside, then tape the opposite side. Kind of like lug nuts being attached to the wheel of a car. Of course you can do this however you like, but make sure it's taped on very tightly and also ensure that your filter core is lined up straight with the reducer.

Once you've completed this step, you should end up with this:


Step 11:
Ok we now have a majority of the filter complete. Now just for the finishing touches. This part is also somewhat annoying, but you only have to do it once. Moving on..

Take out the other package of leggings and cut them the same as we did on the previous package. You'll also need to get out the large 6" hose clamps and batting as well.


Take your batting and make a 4" thick strip that will be long enough to go around the 6" duct reducer once and slightly overlap. Then fold the strip in half, and then in half again as shown below:

awesome, good work and thanks for the tut.

Thanks!

Thanks!

Please - let me know if anything needs to be edited or if I left out anything important. I was pretty blitzed when I posted this tutorial.

Then take this rolled up batting and stuff the inside of the reducer to fill the space between the filter core and repeat. You should have this:


Step 12:
Take out the 6" duct cap and set it upright. Put the filter on top of it as shown to figure out how much more mesh you will need for the filter shell.


Now cut some more mesh and also be sure it overlaps about 1-1.5" just like we did originally on the core - except this time we're working with a longer piece since the exterior shell is 2" larger in diameter.

You can use the 6" duct cap to roll the mesh around to find the size again. Or you can measure, however you prefer. Once you have the size you need, wrap it around the front of the filter (the reducer side). Then attach the 6" hose clamp. You should end up with this:



Once that side is on, add the 6" duct cap and do the same. You may need to size the mesh some, but tighten it somewhat loosely. (You want the 6" duct cap to be as close to the 4" duct cap as you can. ) You still want it tight, but we will be removing it again soon. Your filter should now look like this:


Again, if you ended up with some gap on the part that overlaps, you can do the wire trick and lace it up and tie it down like so: Keep in mind this will also help the structural integrity.


Step 13:
Now just as we did with the filter core, take the other 'socks' from the leggings and stretch them around the filter starting from the reducer side. It will cover the reducer hole which we will get to later. Again you will have two layers just as we did on the core. So put that second 'sock' on as well. Make sure to roll the socks up to the hose clamp, but dont let them unroll all the way.


Step 14:
Now flip your filter over and remove the duct cap. This is the step you will follow in the future when you need to replace the carbon every 2-6 months. Now get out your carbon and fill up the space between the core and the exterior shell. Try and do it evenly and make sure the core stays lined up straight with the reducer to allow the air to evenly be distributed. Once you fill it to the top we will add more batting in the same manner we did before. You should have this:


Stuff that batting in good, but very carefully. Try to avoid snagging it on the mesh. Once done, add the 6" duct cap back on and tighten it down good. Again, longevity, not overkill. Also be patient, this can be a bitch. Then you can finish rolling the socks up and over the hose clamp. I stopped mine at the end of the duct cap, but do what you like. Here's what I did:


Step 15:
The last step finally! Flip the reducer back over so the duct cap is on the floor. Cut the sock to make the hole where you will be connecting your ventillation to. Then you can roll the sock down some if you like. Here is the finished product!



Yeah I know it's not the most glamerous looking thing on the planet, but hey, it will help prevent your nosy neighbors from calling the bacon company to your home.

Nice, very good details sweetie.

Thanks! I know that these scrubbers can be extremely beneficial if stealth is a necessity which it is in my case very much so. Hope it can help everyone in need.

Durban, super job, just finished mine last night, i picked up some ducting sealant also(caulk form), says it increases duct seals by 30 %, every little bit helps, nice work, bd

Wow! Great how to guide.

Can you tell me how your chart was calculated?

I've been looking for a formula for filter area vs air flow for computer fans.

nice job, three thumbs up...
okay maybe just two thumbs up, but it's all I got.

Sweet. I've made a few of these and one thing i could recommend is using welded wire instead of the hardware cloth just be sure to smooth out the rough welds as they will snag the panty hose. Good work.

Sweet thread man, very thorough and informative I'm awfly stoned but how does the carbon not fall out the end where the second batting is, does the 6" clamp keep it all in place somehow? Thanks a bunch for the step by step

i built 2 of these about a year or so ago, they work great. Nicely done on the thread. Finished product looks very pro.

My Filter

My Filter

Sorry I didn't post the last pic - i figured it was self explanatory lol. You put one more cap on the end. Heres a pic of my soon to be setup for an NGB Style cab.

Oh yeah about hardware cloth - take Chiefsmokingbud's advice about the hardware cloth. Hardware cloth works, but it doesn't keep its structural integrity as well as welding wire i'm sure. The cloth is very stretchy, but to help it keep its form - just pack a lot of carbon and batting in and make sure to take the tip about ripping off some of the wire and using it as thread to sew up the parts that overlap. You could also throw on an extra clamp if need be.

durban that is a really awesome cab u have there!!

and also i really like the home made carbon filter as well...

your whole setup looks really professional i must say!

Great info durban 100% what i needed,
good job and thanks, will post pics of mine if it all turns out well

Man you guys - that's awesome to hear. Good to know that I can help out some in the community. Let me know if anything else needs some explanation. I'm really going for the goal of 'For Dummies' so the not so crafty people can make it too. That's me in some cases. =) I have a green thumb - not wooden... usually.

All right guys - let's see how they work out! USE THE HARD MESH FOR THE EXTERIOR CORE. IT WILL PREVENT SAGGING SO YOU DON'T HAVE TO PACK SO MUCH CARBON INTO YOUR FILTER

I used 1/4 inch hardware cloth (nice and springy) with a piece of screen door material cut to size laid over it. It pretty much sticks to the hardware cloth on sharp edges by itself, bt you'll have to push it on a little. It pretty much eliminates the need to stretch panyhoes over the outside, though I did over the inner 6" filter with a lot of work. The outside 8" was impossible, so I'm glad I had already bought the screen.

How is it that you get a backdraft if your inner core is too short? Wouldn't it just blow it through the filter faster with less surface area? I followed your formula and made a 24" though. It's huge, gonna be hard to conceal unless I sit it on top of a cab inside a box.

Thank you DP!!!!!

PEACE

Bonz

Any chance you can edit your post so the pictures are large, so we don't have to click on them? Great tutorial by the way... could you also expound on this statement?

And so on... Just remember that if anything, you want to overshoot the height by about a half inch more than you need, otherwise you get a nice little backdraft and you filter nothing - like i did the hard way the first time lol. Filter the air - don't blow it around.

Click to expand...

thanks!