: i'm in the process of intial sanding. i seem to be getting white spots
: showing up along the seam tape.i'm not hitting the glass , i don't think.
: they just show up. any ideas on whats going on and possible fix. wetting
: it down hides most but not all.

: thanks , charlie

It's most likely glass you're hitting, pretty easy to do when sanding, specially if the glass wasn't perfectly flat ahead of time.

Bill H.