So far this is what I have done with this hatch template.
Three screws to hold the template in place, long enough to protrude through the duflex.
Trench around the marked out “cutout to be” down to the underside laminate.
Underside view through the laminate.
Filled with rolled up wet out unidirectional and runny glue mixture.
After the resin was cured and the overfilled trench is sanded back level, I put the template back on and cut around with a 2.5mm straight bit.
The 2.5mm bit is too short to cut right through so I had to cut again from the other side and then run the jigsaw around for the 3mm remaining.
….. and there we have, two reinforced edges at once, all I have to do now is turn these into well sealing flush hatches!
The Scrumble Project 