Remember to 'blue tape' the edges for like 3 strips to prevent jug saw chatter and marking your trailers paint.. I also taped the bottom of the jig saw..

This is the 1 1/2" x 1/8" thick AL angle channel. Not done yet totally but I started framing it out.. Very rigid stuff.
This will be bolted/screwed to the floor with 2 small AL pieces and up top to the top of door frame with 2 more small AL pieces..
I the hatch inner flange (there is 2" of depth and about 3/4" overlap) onto the AL..

Hatch installed.. with butyl tape and 11 white SS screws..

Test fit of A/C thru hatch.. I will have the hatch supported off the A/C top vents so it will breathe properly..
I did not do the external AL channel (yet) that will bolt thru to the inner pieces of AL for even more rigidity.

Overall I am feeling happy.. I can do the AL inside the trailer anytime and just run the heater..
