I recored all the hatches on my 1975 18 and on my friends 1972 23.
Trying to remove all the "dry strands" is almost impossible without grinding the existing glass to nothing. It gets so thin so fast.
The glass on my 18 was a little thicker than the 23. The hatches on the 23 ground away to nothing so fast, I burned through in a couple of spots.
What I did was remove as much loose stuff as possible with, I think a 60 grit on a grinder.
Got it mostly flat, then wetted it all out with un-thickened vinylester.
Let that kick for a little while, and while it was still green, backbuttered and bedded down my core with vinylester hull and deck putty.
I put some weights on top (batteries I think) and troweled and filleted the edges where it squeezed out and let it kick again for a little while.
While still green but not wet, I wetted out templated and pre-cut 1708 and laid that over the top smooshing it into the corners and edges and getting all the air out.
Then let it all kick.
Worked out great.
Just remember to bevel or fillet the edges of your core, as the 1708 will not wrap around a 90 degree corner. And when you get to the "add weight" part of it, put the hatch on a nice hard FLAT floor, garage, basement, whatever.
I did one hatch on my 18 that I left up on a wonky workbench and it got a weird little twist in it.
