[distracted]

OK, thought this may be useful to some people if for no other reason than to show how easy it is.

I bought my carbon from Greens Horticulture they sell by volume not weight so to work how much I needed I worked out the volume of the whole filter in litres and subtracted the volume of the empty centre…. Mine was roughly 15000 cm3 or cc’s so I needed 15 litres of carbon. If you are buying by weight then you need to multiply the volume in litres by 0.45 kg to get the weight in kg's.

The dead filter


One of 4 rivets holding it together


Rivet drilled out with a 4.5 mm drill bit


With the top lited off


with the carbon tipped out


I washed it out as it was dusty inside (I blow into my filter)


The carbon from Greens


Some news paper helped guide the carbon in


Filled to the top after repeated tapping of the sides to settle the carbon down


Riveting back up again although self tappers or the like would have been enough



10 mins start to finish and not as dirty as you'd expect!

Edited to add: cost me £30 for the carbon for a 200mm filter

The filter in the pic was ~£100 new 4 years ago and it's an 8 inch filter. The carbon you need is 4mm air purification activated carbon pellets (google) this is the standard industrial air purification pellets used in industry, they are little black cylinders.

A quick guide based on different diameters of duct won't work as filters are different lengths from brand to brand, but the maths isn't hard, especially if you use an online volume of a cylinder calculator. First measure the outside width / diameter of the filter in cm then measure it's height, using the calculator you will get the volume of the whole filter in cubic centimetres or cm3, this figure is the volume of the whole filter. The centre of the filter though is hollow so we don't need to buy carbon for that so we take the height or lenght we used in the first calculation and the internal diameter of the filter, which is probably the duct diameter, we then work out that volume and subtract it away from the first volume we worked out. This final volume is the volume of space filled with carbon in the original filter in cubic centimetres, we divide this by 1000 to convert it into litres.

1 litre of carbon weighs 0.45 kg so if you worked out your filter volume to be say 10 litres you need to buy 4.5 kg of carbon, a 5kg tub is less than £40, although that was a quick google and a more intensive search could reveal cheaper prices... don't buy of fleabay though as you can't tell spent carbon from fresh.

If you can't deal with the maths then pm me the dimensions and I'll tell you how much carbon you need

I am sure top end filters have a better live span because the carbon is more compressed in them, Randalizer posted a strip down of his in the thread and the carbon is partially crushed and bagged, this will give a larger surface area and therefore a longer lifespan but the same filter could still be refilled with standard industrial grade pellets and work at 100%, just maybe not for as long as it's first life

This post has been edited by distracted: 04 December 2012 - 12:52 PM

[erky]

is it a messy jod? is there diffrent grades off carbon? is it much cheaper? thanks

[arai]

excellent work distracted

are you going to re rivet it ?

This post has been edited by distracted: 10 October 2012 - 09:57 PM
Reason for edit: edited to change name

[mark..uk]

hi distracted, they say that budget filters are not refillable, how come is that mate?? surely i could do the same yes ??

thx

This post has been edited by distracted: 10 October 2012 - 09:58 PM
Reason for edit: edited to change name

[Gr33nLungs]

thanks man i was wondering if this was possible
them filters are pretty expensive.
how long does the carbon last, how many grows do you get out of them?

[distracted]

Mark, I reckon they say budgets aren't refillable so they get to sell you another one every 18 months

MrM, the carbons meant to last 12-18 months, how many grows depends on what you grow and how many rooms you have but mine was more or less in constant use for 2 years and over the last couple of weeks its has been struggling to handle the stink

[Om]

Might be better to use a self tappers cos if you got to drill the old rivet out everytime the holes size is going to increase and break through. Self tappers should be fine or you could use a spot from a hot glue gun.

Excellent thread distracted just what this site is about..............DIY.

Good one for pinning I reckon

This post has been edited by distracted: 10 October 2012 - 09:59 PM
Reason for edit: edited to change name

[playground]

First rate stoner engineering. My hat is tipped to ya'. I run a CAN 33 filter and have had it in operation for a few years. It will need to be replaced soon and this is a lot cheaper than just ordering a new filter. I bet I can beat that 10-minute time. Lemme' see... I smoke some meth. Do a couple of hits of cid and then sit on some fire ants for a while. Yep, I can get it done pretty quick.

Well done!

This post has been edited by distracted: 10 October 2012 - 09:59 PM
Reason for edit: edited to remove name

[podgy]

distracted, on Dec 8 2008, 12:03 PM, said:

the carbons meant to last 12-18 months, how many grows depends on what you grow and how many rooms you have but mine was more or less in constant use for 2 years and over the last couple of weeks its has been struggling to handle the stink

that's really good to know...

This post has been edited by distracted: 10 October 2012 - 10:00 PM

[smokie1 b c f c]

thats a good old bit of ganja man diy. im going to refill my 1.and the grow shops must be making £ for refilling them now. f that diy.cool

[Abe Froman]

Had an idea after seeing a vid of these being manufactured.
they use a vibrating stand for the filter when the carbon is being put in. how about using an orbital sander without any sandpaper fitted perhaps safely clamp it in a workmate and stand the empty cf on top , bobs your uncle.
if no-one gives it a go before i need to refill mine i'll try and get a gude up if it works...

[smokie1 b c f c]

Tremont-Salby, on Jun 8 2009, 10:25 PM, said:

Had an idea after seeing a vid of these being manufactured.
they use a vibrating stand for the filter when the carbon is being put in. how about using an orbital sander without any sandpaper fitted perhaps safely clamp it in a workmate and stand the empty cf on top , bobs your uncle.
if no-one gives it a go before i need to refill mine i'll try and get a gude up if it works...

place it in the box you got it in ,and place on a tumble drier for half hour and it shakes the charcoal down nice and compact,i held it ontop wile smokein sum bubble ,

[Chillation]

kingbud420, on Jul 29 2009, 11:47 PM, said:

excellent useful info... have bookmarked this page for when the time comes.. will save me a fortune.. thanks very much!

Guys
I have just this minute spoken with Greens they no longer sell the carbon! Anyone know of a supplier?

Chilii

[sir smoke allot]

I thought carbon was charcole. If so instead of buying it why can't we jus burn a load of wood and break it down to dust. Or jus buy a bag of charcole. Obviously I'm new to carbon filters never needed 1 till now so I'm sorry if this seems like a stupid question. And props to billius good info man. Stay keen keep it green