Sonotube loss corrections

As I've mentioned before, I've got ahold of one of those big sonotube-forms.
According to Richard's Guide the Colorado Springs Notes (May I add that I
HIGHLY recommend this book to any Tesla builder, even if they don't own a
copy of the notes. It can be had at:
9-0607813 ), the card board material is about the worst thing on the face of
the earth as far as overall Q goes. I know it should definately be treated
to lower conductivity. But what can I do that will help the loss? I know I
can't all but eliminate it, but, how much improvement would a layer of LDPE
glued over the form offer? I'm assuming the underlying cardboard would still
"hold back" the form's effect on Q. Any ideas on effectively reducing the
loss on these terrible (but cheap!) forms?

      Thanks a bunch,