Derek,
There’s a company called Commercial Body Fixings(CBF) in bristol and manchester, they sell a range of bonding tubes for a standard “mastik” gun. From experience as a coachbuilder for 12yrs it’s awesome, the grip is good but not instant. Its the stuff used for bonding caravans together, aluminium bodies, grp panels etc. Only trouble you have to buy it in boxes containing 12. Very good tho if you can leave to cure overnight. Hope this helps.
Regards
P.s. sorry, didnt notice you needed today. Just make sure its a tube made from polyeurethane not silicon. Personally i dont rate silicon very well.
Oh dear i sounded like a right geek then
Matt