Internal circlip of some sort ?

[Jethro_uk]

One of my hobbies involves an activated carbon filter to remove taints from a liquid.

For reasons unknown it seems impossible to source a new filter - as various shops are discovering.

Rather than fart around, I've taken a look at the beast, and believe I can probably make do & mend.

The filter comes as a cartridge which is made of plastic. There is a retaining hexagonally-punched circular plastic ring which is spot-glued/ welded to the body.

My current thinking is to use a knife to sever the welds, and remove the plastic retainer. At that point, I can remove the old carbon (which seems to be in a mesh or net) and replace with fresh activated charcoal (available for 2Kg/£11).

The only issue then is to be able to replace the plastic retainer securely. Ideally in a fashion so that I can repeat the process ad infinitum (in the anticipation that the new filters are going to be impossible to source).

This leads me to a couple of ideas.

1) a series of screws from the outside in (there is plenty of room where the filter is located, so no worries there)

2) some form of internal expanding circlip which will hold the plastic down firmly. However, there is no groove inside the housing. I am imagining some sort of inside-out worm hoseclip that can be opened with a spanner to grip the sides.

as a final complication, whatever the solution is, it needs to be water (and alcohol :) ) resistant. So steels and irons are out. Brass or copper ideally.

[The Natural Philosopher]

re weld with a soldering iron

[Jethro_uk]

Totally possible, but then it becomes a limited lifetime procedure ...

[Harry Bloomfield]

Jethro_uk explained :

You could make an internal C clip from stainless steel dental wire, it is quite springy. Another thing which might work is a stainless Jubilee clip, around the outside, just tightened enough to retain it.

[The Natural Philosopher]

Not really. you can get nylon rod as a welding stick or similar

[alan_m]

Drill holes and use cable ties?

[Tim Lamb]

Cannibalise some child's *slinky*?

[newshound]

What's the problem with just fabricating something? I can't quite follow your description and picture, but how about:

A length of 38 mm PVC waste pipe. Two rubber bungs to fit (ebay, including ready drilled ones). Some suitable mesh to stop the carbon going down the pipe, e.g. cut from a stainless steel tea-strainer? Fill with activated charcoal. Replace as necessary.

If 38 mm is not large enough, you could build something based on 110 mm soil pipe with rodding eye closures to block each end.

PVC or ABS and nitrile rubber won't taint your distillate (sorry, mystery product) once any release agents, etc. have been washed off.

Copper pipe for plumbing goes up to 54 mm and various copper or brass fittings will be available (at a price). Try Yorkshire for a start. You can even daisy-chain reducers if you are starting with microbore from your condenser (sorry I mean if you are using small bore elsewhere in the system).

[Andy Burns]

Why not use Brita Maxtra filters, with some sort of heath robinson input/output plumbing adapted to the jug?

The genuine cartridges are on offer every few months in supermarkets, or "compatible" ones from ebay/amazon about £2 per 100g of charcoal (plus some ion-exchange resin beads?) ok works out at 4x the price of the raw charcoal, but the convenience of a plug in filter?

[Jethro_uk]

Just gravity. I think the plastic retainer is pressed in so that the liquid is forced *through* the carbon, rather that around ...

The plastic housing I showed screws into a bigger body with another - ceramic - filter above it.

The ceramic filter removes physical impurities, and the carbon filter removes organic ones.

For those who wondered, the whole assembly filters ("polishes") distilled alcohol. And has done wonderfully well for 10 years :)

[Jethro_uk]

That's not a bad idea ... the cable ties are renewable, and pulled tight would ensure the carbon is packed tight enough to prevent the liquid bypassing it.

It's my current favourite :) !

[Jethro_uk]

I should have explained that the pictured housing is part of an assembly (there's a screw thread below), so I need to retain it to fit back into the whole.

[Jethro_uk]

As I said to a PP, the pictured filter screws into a bigger assembly.

[Jethro_uk]

I thought of an inside-out jubilee clip (which I couldn't name yesterday ! Old age I guess). But that's steel, so might be adversely affected by immersion in water/alcohol.

[newshound]

OK that wasn't clear. Rather than faff about trying to open and then re-close a "sealed" container, I would still *think* about fabricating a refillable cartridge to go into the same space.

But then I really do like making things!

Many, many years ago when I was a lad, I asked a technician to machine up an adaptor out of brass bar to fit on a research rig. I was slightly irritated when, instead of doing this, he hunted around for ages looking at available plumbing fittings before making up something that did exactly the right job with just a single machining operation. It wasn't elegant, it had an un-used external thread and hex section. But it was a very effective and creative solution. And a *very* good lesson which I have never forgotten.

[Jethro_uk]

I must admit, the advent of 3D printing could be a game-changer.

Digging around for a dashcam mount the other day, I noticed an eBayer was selling home designed and produced 3D printed components.

[Adam Funk]

Wouldn't stainless steel be suitable? I'm inclined to think it would be less likely to impart a metallic taste than brass or copper.

[Jethro_uk]

I believe the Japanese have delivered some acceptable results using stainless steel stills (todays tongue twister). But copper is almost universally accepted as the norm ...

[Harry Bloomfield]

newshound explained on 22/06/2017 :

I like re-purposed ;-)

Over the weekend, a U shaped bent steel tube giving support to our hose reel finally rusted through (out in the weather 24/7). Before it finally snapped, I had already decided I would replace it with something rust proof, but what. I had no means to bend tube, nothing near the right diameter either of 21mm. I ended up making it from 15mm copper, with two elbows, then sleeved the ends of the U with plastic conduit to bring the diameter up to more than the 20mm needed, araldited on then turned down to the 20mm diameter needed.

It was never designed to be permanently mounted outside, but outside on a wall by a tap worked best. I had fixed it to the wall with 3x 20mm galv saddles via its 2x U brackets.

[newshound]

Nice to read some real DIY content today!

:-)