ok, so heres a basic run down of what has been happening on my build.
tape a giant area off, and mark off where the 14x14" hole is going to be cut.
drill the 4 corners and cut out the square. i used a cut off wheel on a die grinder. quick and dirty (like my jokes). i have access to everything, all the cutters, air nibblers, shears, etc etc, but i chose the die grinder because i am well versed in its usage.
PRO TIP: tape a trash bag below the area you're going to cut, this seriously kept out 98% of the crap that would have gone all over my bed platform (i removed the cushions)
Couple quick shots of the fan up there, kinda just seeing how monster this thing is. i really wish they made like a 8x8" fan, cuz this is totally overkill. the only other powered fan (size anyways) is a vent line vanair and its like 6.25" circle, pretty noisy due to the "squirrel cage blower" and only has one speed. go big or go home i say.
Obligatory head thru the hole in the van shot.
now, ill 100% admit to getting in the groove and getting this MOFO installed for the night, i forgot to take a picture of @Hein 's BEAUTIFUL adapter, this thing is NO JOKE. its CNC machined to match the curvature in the roof, both front and back, and side to side (like EZ-E's switches), fills in the ribs in the roof to perfection. Well worth the entry price of ~$65
taped off a perimeter, dulled the paint with a Grey scotch brite pad, wiped down with isopropyl alcohol, let dry
i used 3M window weld as spec'd in the instructions, 3 beads 1/8" high/wide all around, light clamps to hold as needed. after the squeeze out, used a gloved finger, and made a little fillet of the window weld, then peeled the tape, nice crispy lines.
DONE!
well, at least with the roof adapter to give the fan flange something flat/level to sit on.
let me tell you, this thing is 100% level front to rear and left to right, very impressed.