How clean narrow bendy metal chimney flue?

[Eddy]

Any clever ideas on this one?

Had a wood-burner fitted a year ago and the fitters "flued" it with a narrow, probably 6" diameter, metal concertina-type flue up inside the original old flue to the roof (probably a distance of 7 metres all in).

Anyway, though I had better give it a clean so I got out my 1-metre rods with brush attachments etc., but can't get up more than a metre. Problem is the bends - combined with the narrowness of the pipe. And, of course, I don't want to puncture the thing by forcing my way up.

Went online and saw that at stovesonline.co.uk they're offering just the thing - a really thin and very flexible "rod", with attachments. Problem is it's £20 per metre!!!!!!!

There must be a cheaper way round this.

First thought is, what about a good stiff garden hose? (No rude joke intended.)

Anyone already come up with an effective solution to this problem?

Eddy.

[The Natural Philosopher]

Try the old shotgun up the flue trick.

:-)

COULD use blanks..

[nightjar]

Find a close fitting, heavy, ball and drop it down from the top.

Colin Bignell

[RubberBiker]

First off, go easy on it. You don't want to damage the smooth inner layer of the flexi.

(solid fuel flexis have a corrugated outer layer, and a smooth inner, with the edges of the helical inner winding facing downwards - the idea being to reduce places for moisture/tar to get trapped and start attacking the stainless)

I use conventional rods & brush - but the angles aren't too tight it mine. You might like to look at hiring the kit, using a professional sweep, dragging a brush through on a rope from the top - or simply caving in to the cost of good rods.

[John Weston]

Preferably on the end of a rope, otherwise when it hits he hearth it goes bouncing across the room :-) - or gets stuck on the way down :-)

[Owain]

Something like a pressure washer drain cleaning end, but with compressed air instead of water?

Radio-controlled model helicopter with brushes on the rotor end, and CCTV camera so you can see where it's going?

Long-haired cat, hairspray it so the fur forms bristles.?

Bass guitar amp in the fireplace pointing upward, and vibrate the soot off.

Owain

[Eddy]

Feasible! Blow the lot out of the top too, so no soot coming downwards!

Very amusing! LOL.

Eddy.

[Eddy]

Yes, that's was one of my worries.

Dragging a brush through from the top sounds feasible, although I wouldn't like to be trying it when I'm a bit older.

Haven't thought about getting a quote from a sweep. Worth seeing what they charge, at least.

By the way, I discovered in my abortive attempt to do the job this morning that the first metre and a half is absolutely clean. Do you think this might mean the whole thing is absolutely clean? Does soot tend to only gather higher up? (I only burn wood.)

Eddy.

[Eddy]

Ingenious, Colin! And put a good strong net up in front of the grate so it doesn't charge out when it hits the bottom and dive straight into TV screen?

Eddy.

[Eddy]

Yes, a good idea, the rope, in case of it getting stuck. And maybe not to close fitting either. Actually combine Owain's idea of cat sprayed stiff with hairspray with the ball and come up with a ball-brush. Still has me on the roof though, which I'm not to keen on!

Eddy.

[Eddy]

In an old Welsh farm-house with 18"-thick stone walls, perhaps! But not inside this delicate metal flue. Can't afford to put a hole in it.

Eddy.

[The Natural Philosopher]

That's a neat one. Never thought of that.

[Tim Lamb]

In message , Eddy writes

They offer a modestly priced 6" brush. I believe you can use conventional drain rods if you purchase the adapter bush.

You could use a torch and a mirror to examine the flue further up. The first few feet are likely to be hot enough to stay clean.

As others has said, be very careful.

regards

[The Medway Handyman]

Commercial kitchen extractor ducting is cleaned by something similar using steam rather that HP water.

[RubberBiker]

Hmmm - soot with traces of sulphur compounds plus water and you might create sulphuric acid - particularly with high pressure water or steam, this may exactly what you don't want to drive into the joints of the liner.

[Dave Liquorice]

Yeah but soot is dry and crumbly not a thick, sticky, greasy, gunk.

TBH the thought of stuffing a pressure washer drain cleaning head fed with compressed air(*) seem to me to be a very good way of filling the house with soot. Even with a soot proof sheet taped over the opening and a proper entry for the manual poles and a vacum you still get soot into the house.

As for the OP's problem. I think short of going up onto the roof and looking down from the top to see what that is like. Does it need a sweep? Don't forget rain might clean the top few feet. A set of more flexable rods or bringing in a sweep is the best bet. For a pro-sweep it's only a couple of hours so I'd expect change from =A3100. If he has to travel over 20/30 miles it might be worth getting in touch with others nearby and arranging to all have your chimneys done on the same day.

(*) Getting a high enough volume at suitable pressure supply of compressed air might be a problem. I doubt yer average 2 or 3hp compressor would manage it.

[Eddy]

Thanks, Tim. I see they advertise:

"Flexible nylon rods:- These rods are available in 1/2" diameter and are designed specifically for use when sweeping chimney liners. They have brass universal fittings and connect directly to the brushes without the use of the adaptor below. Each is 1 metre long."

But they don't give any idea of price. Will email them and see if each

1-metre rod is less than £20 each.

No, can't you conventional drain rods. Have them already. Nearly an inch thick and no flexibility in them for getting around the 45 degree bends.

Right. So a clean first few feet doesn't mean it's clean much further up. Thought that might be the case.

Taking every precaution.

Thanks again. Eddy.

[Eddy]

Unfortunately, if I were to get up on the roof I couldn't see down it because of the cowl permanently fixed to stop rain getting in.

Thanks for an idea re. price of having a sweep in. Bearing in mind the need to have the job done annually, as we have the stove going almost each night from November through to May, the cost of the ultra flexible rods and brushes would be more than repaid after two years.

Eddy.

[Eddy]

How about the idea of just chucking down half a dozen hedgehogs then? :-)

Eddy.

[Tim Lamb]

18 or so, not much help! You get prices when you go to the purchase page.

Cowl off and down from the top? Presumably the acute bends are in the bit at the bottom?

regards