Hi Virginia Overlander.
i have now finished the TD and the doors did not spring out and do not need the strap to tension them. They fit really nicely.
i did apply the stiffeners before cutting out the doors, as well as the extra layer of glass fibre on the inside of the door as shown above.
I aligned the door stiffeners on the inside of the caravan using some short steel rods of about 10cm long by 1.5mm diameter. I used one of the alignment holes at the bottom of the stiffener and drilled another through the stiffener and shell toward the front of the stiffener. Because the rods are rigid, unlike the copper wire, they keep the stiffener aligned correctly to allow the stiffener to be glued accurately in place.
I used part of a (UK) mains plug which has a grub screw that holds the rod tightly. With one of these on the outside of the camper the other one on the inside can be used to pull against the rod, and with glue on the stiffener, it can be braced against the shell and the second gripper slid up against the stiffener to firmly hold the stiffener in place.
I left the ‘clamps’ and rods in place until the glue cured. To get the rods out I heated them with a blow torch until the epoxy softened and the rods could be pulled out. Take care when heating the rods to avoid scorching the wood, like I did! It is safer to heat the rod from the inside just in case. The hot rod didn’t scorch the wood it was me pointing the flame towards the wood that was the problem – I only did it once!
Clean up the oozing glue before it sets of course.
Hope this helps.
Andrew