Collaring the chimney
QI need to replace the badly corroded collar on the roof of my Springer. How can I remove the old one and seal the new one?
The chimney collar is more often than not a very heavy chuck of cast iron, and although it may rust that’s likely to be superficial. Springers are getting on now and, being a budget boat, may well have done something a bit different with the chimney. They could have even welded the stove pipe to the roof. Usually, the collars are held into the roof by two bolts or studs. You might need access to the underside of the roof to undo them.
I sealed mine with a bead of high temperature (stove) silicon around the boss and one of the more normal marine sealers over the rest of it. I used a Sika product, but there are several others.