Dig some of the foam out and try different solvents in a can or cup before pouring a whole lot of anything down the inside of the mast. That foam may be a lot more chemical resistant than you think. Any way you slice it you are going to have a very time consuming caustic mess. You might want to try and remove as much of the foam as possible by mechanical means before resorting to chemicals.
Regards,
Bob
Last edited by Seeker; 08/07/07 04:36 PM.