On Wednesday, June 24, 2015 at 9:45:25 PM UTC+1, Fredxxx wrote:
This would be for a sealant between a sleeve and a pipe carrying gas.

I notice that the IGEM procedures use the term "mastic seal" as an
example but the description "mastic" is very vague.

Can anyone provide what sealant the trade use?

Plumba Flue Is widely for this job.

Note that a seal is only used on the the interior sleeve in a building.

The exterior of the sleeve is left open