GMC Topkick 4x4 Expedition Camper Build

Started cutting out for windows. Got one of those Harbor Freight pneumatic nibblers, for just $25. Low expectations which were met !!
Anyway, marked out windows, taped on a straight edge and cut out the holes. Used a plastic coffee can lid for corner radii, about 3", and free-handed them.
So quite successful. Now waiting for one more window and the butyl sealing tape, then I'll pop rivet them in place.
We changed our mind on some of the sizes, so we have some windows for sale ......
We decided to pop rivet them for 3 reasons - 1) the walls need to be fully finished inside to use the mounting rings supplied; 2) the whole box is riveted, so a few more will be OK; 3) They'll be really solid in place with the mastic.
Cutting windows.JPG
Last edited:
Started working on the inside framing. The roof bows are about 1" thick, as are the side ribs; about 16 gauge galv steel.
Going to need a lot more stiffness, IMG_1420.JPG IMG_1421.JPG IMG_1422.JPG room for wiring etc, and insulation.
So we got some very light weight steel studs. 25 ga, 1 5/8 x 1".
Put those up in the ceiling today, 16" on centers, using self tapping screws. We put a rib down the center of the roof bows and tied the new ceiling joists to it, for rigidity.
We have 4 1/2" in the center, and about 3" at the sides for insulation. Yes there will be some very limited "thermal bridging" but not really significant. Should be toasty with about 2 1/2" in the walls as well.
Last edited:


Expedition Leader
FWIW I use the Maxxfans too, they are nice. But get the ones with the remote..... I wish I had! I have to get out of bed to turn them on/off. :D


Expedition Leader
Thanks Java.
I'm at the age when I have to get out of bed regularly anyway, lol :)
Just seems so much $$$$$$ for a 12 volt fan....
I agree completely, they are expensive, but I wish I would have spent the extra 50 or $100 for the remote. I leave them on all the time, and sometimes it gets chilly at night when they're blowing in and you don't want to get out of bed! My ceiling is also seven and a half feet tall and my wife can't reach the fan controls...

Sent from my SM-G950U using Tapatalk
Thanks Java. Similar problem - tall ceiling, 7 ft, and short wife.
B65, strange you should say that. I was thinking the screws are meant for a building, which sits fairly still, except maybe on San Andreas fault line. So I figured I better add some adhesive - did that yesterday afternoon.
I'll pull out the screws and check one of the joints today - Thanks !!
Start to install windows today. I have to cut through a couple of ribs, so it will interesting to see how much stiffness I can put back into the wall by framing out the windows with these 1 5/8" studs.
Cut my last window hole yesterday, which meant cutting through 2 ribs. Obviously this severly weakened the structure, so I braced with "headers" etc and it turned out pretty strong, I believe.
Installed first window as well. Turned out pretty good I think.
Next job is to sister up all the ribs with 1 5/8" studs to give me about 2 3/4" overall wall thickness.
kitchen window 1.jpg kitchen window 2.jpg kitchen win 3.jpg kitchen win 4.jpg
Jerryl, not a Union job - no conduit LOL !!!
Seriously though I need to pop several holes in the 25 ga studs for wiring, and protect the wires with some sort of grommet.
I bought a little hand punch from Northern Tool which is great, but the biggest punch that came with tool is 9/64". I'm interested in suggestions on making wiring holes, and grommets. I might run the smaller wires in the flexible wiring "conduit" you see on cars, etc.
Thinking about sprayfoam because that would give great insulation and stiffen everything up. Anybody got any experience with the DIY kits please ? Getting a contractor in might be high $$$$$$.


Expedition Leader
Look for a metal stud punch, they make them for doing electrical, ~1.5" hole, and they make grommets that snap right into the holes.

DIY spray foam kits work, but are $$$ too, I went the pro route and am happy I did, grinding that **** back down SUCKS. It took two guys with 4" cup grinders at least half a day to do my truck.
DIY spray foam kits work, but are $$$ too, I went the pro route and am happy I did, grinding that **** back down SUCKS. It took two guys with 4" cup grinders at least half a day to do my truck.
sounds like a used old electric meat knife to carve it down first would be ton faster. Or a heated wire running just long enough to slice down width across one stud to another or maybe even a wire saw for same purpose. Heat maybe not needed?
Last edited: