What are the best option to seal the connection .

[Dmitry]

Relining my insert with new hybrid liner instead of cheapo that was installed 10 years ago and failed.
The liner comes with a slight angle due to limited space.
What is my best option to make this connection airtight?
The furnace cement failed in the past crumbling. I used gasket rope with cement in the past and seems like it holds up fairly well.
What are other options I have?

 

[BigJ273]

I think a 15 degree appliance adapter But I’m no professional

 

[begreen]

I think a 15 degree alliance adapter But I’m no professional

Agreed. Use the left adapter.

 

[Dmitry]

I see. Do I need to use any kind of sealer or it should be tight enough?

 

[begreen]

That depends on the whole size. If the gap is 1/16" or wider, flat, stove gasket material can work better to fill it.