heat-proof silicon

davemorton

I tried to seal the are that my flue pipe enters the stove with heat resistant silicon (meant to be good up to 1500 degrees C) After leaving it 3-4 days, I lit the stove. It gave off some smoke, but after a couple of uses has went brittle and just cracked out. Is this not suitable for this job?? I was just trying to avoid using fire cement.
On a side note, I lined the chimney, and have got a register plate up, does the register plate need sealing all the way round, or is a snug ft okay for the regs??

Cardew

I think the correct grade silicon for that type of job is in all those French implants that are being removed; should be a lot cheaper soon.

muckybutt

davemorton wrote: »

I tried to seal the are that my flue pipe enters the stove with heat resistant silicon (meant to be good up to 1500 degrees C) After leaving it 3-4 days, I lit the stove. It gave off some smoke, but after a couple of uses has went brittle and just cracked out. Is this not suitable for this job?? I was just trying to avoid using fire cement.
On a side note, I lined the chimney, and have got a register plate up, does the register plate need sealing all the way round, or is a snug ft okay for the regs??

You want flue sealant, its not a silicone based product .... kind of a ceramic type putty you inject with a silicone gun. Just type it into google

rainybird

we use fire cement then spray it with car exhaust black spray paint smells for a couple of days but hasn't cracked yet & we did it beginning of november.

w50nky

You really need to use fire cement for flue joints, it is available in black and you can dress it with a damp cloth before it sets to obtain a neat finish. The silicon sealant is good for a short period of time up to the rated temperature and it does harden when it is subject to heat. It is not meant to be exposed to naked flames as found around flue pipes at the top of the stove.
It is normally used in fire breaks in buildings etc.

You can seal the joins around your register plate with fire cement too. If it`s a large gap around the flue pipe you can use a collar around the pipe which is designed for this purpose.