Cutting vitreous flue for wood burner

[rh2205]

Issue is in the title we need to cut our black wood burner flue so it can fit and it will be on show, damn. I’ve got an angle grinder with some kind of diamond blade in that I can’t get off (neighbour said they used this to cut their aluminium door letterbox so I’m hoping it’s sufficient), is this really going to work to get a straight clean finish on a black pipe ??? Any Other ideas?

[ProDave]

More details? Pictures? where do you want to cut it?  What will the cut end join to?  Why did you not buy the right length etc.

 

I cut mine with a hacksaw, and the cut end goes into the single to twin wall adaptor and the cut end is  hidden inside that fitting.

[rh2205]

@ProDaveI have an adjustable piece which goes in between the gap and the twin wall you can see, I couldn’t buy the right size, 500mm was too short 1000mm too long, twin wall was installed ages ago and is not moveable now. The adjustable pipe slides down into the longer section of pipe you can see as far as the end where it widens to connect onto the twin wall, I can’t cut the hidden male end on the long pipe going into the stove because it needs to be the end which reduces that goes in the stove according to the manufacturer which also means I couldn’t buy a brand of pipe that has more different lengths as it doesn’t have the right reducing end detail at the end of the pipe for the stove. 

Edited November 26, 2021 by rh2205

[rh2205]

So yeah the most painful thing of this whole saga is the black pipe you can see in the photo of the gap had been 10mm further away we could of got the adjustable section of pipe in and then slide it up onto the twin wall! 

Edited November 26, 2021 by rh2205

[rh2205]

So anyway just so it’s clear I need to cut 10mm off the top of the long vitreous pipe you can see in the photo to get it installed. Now I’ll start with 10mm because it will probably need 15 attempts but I’ve got an extra 220mm of error to play with as the adjustable pipe can extend this much

[rh2205]

And just checking @ProDave are you saying you cut the twin wall? Or the vitreous flue? I’m just wondering if there’s another way I can bodge this so you can’t see our bad efforts. I just know we can’t cut male ends which is always the bottom end of the pipe (the section that’s always hidden) and supplier of the last section of flue stressed this too which makes sense based on the meccano I’ve just done.

[ProDave]

Okay so you want to shorten the pipe by 10mm.

 

Are you sure you cannot cut 10mm off the bottom where it goes into the top of the stove?  Won't that still leave enough of the reduced section to go into the stove fitting and that would hide the cut end?

 

Yes I cut the black single wall flue but I cut the top end that goes into the twin wall.

[rh2205]

Hmm weird, I bought the twin wall from the same place as you… (I read your old post a long time ago when putting in the twin wall and it was cheaper there still), but oddly if the vitreous pipe went inside the twin wall that would surely mean any flue pipe liquid could run out of it, the sections I have means that the vitreous pipe is always on the outside even where it connects onto the twin wall. And yes I think I will see if I can loose any male end but it seems to slide quite far down into the stove body so might not work.

Edited November 26, 2021 by rh2205

[ProDave]

That on line supplier I think changed the make of the system they supplied so you may not have the same fittings as me. the twin to single adaptor I have the single flue slides up inside the twin flue but there is an additional pipe inside the fitting that goes down inside the single flue, ensuring as you say any liquid runs down inside the pipe.

[rh2205]

I can report back that everything has been resolved without cutting? just took the twin wall adaptor off slid the stand and stove along the glass contructed all the bits & slid it back in using the extending part to lift it into position, luckily the adaptor was the thinner part and gave the clearance to do this and I decided a scratch on the glass was the least risky option. Now the next issue, it’s not burning amazingly not sure if that’s the weird weather or our place isn’t drafty enough or the conifer of unknown moisture content I’m using! 

[Iceverge]

Well done. Tasty job. 

 

Make sure the wood is bone dry. It makes a huge difference. 

 

Looking at your penetrations to the loft around your twinwall, is pretty well sealed? 

 

If the warm room air can rise up there less warm air is being forced via the stove up the chimney.