"Sean" wrote in message
om...
Thanks for that Lawrence

As the clay flue has a 200mm diameter and the spiggot thats butting up
against it is 140mm , I'll need to taper whatever "sealant" I use at
this point so that the "tars" can run back down the chimney into the
fire. Do you know if it is possible to build this ammont of silicone
at this join? Also as I'll be sealing after the spiggot has been
fitted (which means I only have access throught the 140mm hole in the
spiggot) the "sealant" will have to be applied by hand (no roon for
gun). Being only familiar with the normal silicone products, this
would appear to be a messy job would it not?

I just applied plenty to the plate before bolting up. When it was in place,
I put my hand up the hole and used a finger to smooth a fillet of silicone
round the join. I wondered about condensed tars but have never had any
problems. I assume that they flood the ledge and either come down the
spigot or burn/evaporate in the flue! I burn mostly wood and make sure the
temperature of the flue gets good and high before I turn the air down. I
use one of those magnetic flue thermometers. I don't know how accurate/valid
they are but it is quite fun monitoring the temperature. I know, I am a
sad physicist!!

Lawrence