How to seal flue to insert connection.

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Dmitry

Minister of Fire
Oct 4, 2014
1,153
CT
I've tried 2 kinds of cement. This one http://www.lowes.com/pd_64843-85334-GA0188_0__?productId=1191571&Ntt= and the other from HD. They all fail after some time and I can hear wistling sound from air sucking trough the connection. I've prepared surfuce and followed instructions.
What other option do I have? I'm thinking about foil tape . Is it safe? The RV silicon rated 600f, so its not an option, I think.
 
post some pics of the connection. it it fits right there should be no need for any sealant.
 
Foil tape is not made for hot flue temps. Furnace cement is preferable.
 
I had a similar problem and tied some 1/4" gasket rope tight around the connection. It's not airtight but it stays put.
If you do it with soot on your hands it will even be black!
 
It's hard to make a picture , it's very tight in there and it's insert. The pipe comes in with slight angle . That's why it's not sitting tight enough. The furnace cement holds for couple weeks and then It just crumbles away if touched.
 
It's hard to make a picture , it's very tight in there and it's insert. The pipe comes in with slight angle . That's why it's not sitting tight enough. The furnace cement holds for couple weeks and then It just crumbles away if touched.
Yes it will do that it does not deal well with the expansion and contraction that takes place in that spot. What you need to do to fix the problem is get that liner to go in straight by using an elbow or trimming the fireplace to get the clearance you need to make it all fit correctly. There is a reason we take 4 or 5 different connectors and elbows when we install an insert
 
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Yes it will do that it does not deal well with the expansion and contraction that takes place in that spot. What you need to do to fix the problem is get that liner to go in straight by using an elbow or trimming the fireplace to get the clearance you need to make it all fit correctly. There is a reason we take 4 or 5 different connectors and elbows when we install an insert
I'll probably just will learn to live with it. The whistling can be heard only if 2 feet away and paying attention.
 
I'll probably just will learn to live with it. The whistling can be heard only if 2 feet away and paying attention.
But if it is leaking bad enough that it is whistling it is letting a lot of dilution air in that is not good for the performance. Another thing are you sure that the whistling is from the liner connection? Many times the air intake will whistle if you have allot of draft.
 
The air intake makes its own sound . This one comes fro the top of insert and disappears if sealed with cement . For the life of cement .:)
 
he air intake makes its own sound . This one comes fro the top of insert and disappears if sealed with cement . For the life of cement .:)
Ok then in that case i think it needs to be fixed. If it is leaking enough to make a noise I would say there is to much air getting in there
 
Ok then in that case i think it needs to be fixed. If it is leaking enough to make a noise I would say there is to much air getting in there
What cement would you recommend ?
 
What cement would you recommend ?
I would not use cement there is not any that will hold up. You need to get that connection in there straight. If it is still loose use some gasket material
 
The liner sits tight in chimney stuffed with Roxull and there is no way I can pull it or bend it .the insert is far as it can go . It's just several degrees out of perfect angle . Just trying to make things perfect . Will try gasket rope
 
How about adjusting the legs of the insert? The front higher than the back or visa versa. The face of the unit would be out of plumb but if you only need a little tilt you may be able to live with it to get that flat surface to surface seal.
 
How about adjusting the legs of the insert? The front higher than the back or visa versa. The face of the unit would be out of plumb but if you only need a little tilt you may be able to live with it to get that flat surface to surface seal.
I can live with it but the other half not gonna :). It's like a centerpiece of living room .
 
I can live with it but the other half not gonna :). It's like a centerpiece of living room .

Get half way there so it's barely noticeable and use (2) gaskets!
 
Buy some flat rope gasket and wrap it around a few times then put wire around it and tighten in place you can't see it if it's a insert and that would probably work
 
Yes it will do that it does not deal well with the expansion and contraction that takes place in that spot. What you need to do to fix the problem is get that liner to go in straight by using an elbow or trimming the fireplace to get the clearance you need to make it all fit correctly. There is a reason we take 4 or 5 different connectors and elbows when we install an insert
Anything against the adjustable elbows, bholler?

Just an example of what I'm referring to:

http://www.woodlanddirect.com/Chimney/Chimney-Liner-Parts/Elbow-45-Degree-Adjustable
 
Anything against the adjustable elbows, bholler?
They would be my last choice but yes we carry them as an absolute last resort
 
They would be my last choice but yes we carry them as an absolute last resort
What is issue with them that make them your last resort? I ask because next time I pull my insert I was strongly considering replacing my straight appliance connector with an angled one, and not wanting to buy the whole set to make sure I have the right one on hand, was thinking about trying the adjustable one. I think the 15 degree will work, but maybe the 30 or 45 will actually fit better in practice, but as you know the best way to tell is to try it and see. Oh, and also, the adjustable one will give me a little play from side to side, which might be beneficial in my case as well. The adjustable ones not airtight, or is it something else? Thanks bholler, I always value your insights.
 
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