Teardrops n Tiny Travel Trailers

I am up to page 380 and have a question I haven't seen yet, maybe someone can answer it. Say I want to cut a square hole in a canvas skinned foam wall and I want to do it very cleanly, any ideas?
I can imagine a sawzall would look pretty rough. Electric knife?

Cheap serrated steak knife works great with a sawing motion , just be careful take your time ... You might want to see how it works on some scrap foam first ...
Ps. Worked so well , we included a serrated steak knife in our Foamie repair kit ...

I would pre-cut the canvas with a utility knife and then saw out the foam. I think you would get a cleaner edge to your opening.

I drew where I wanted the opening and cut an X pattern, then peeled the canvas back.
I used a razor knife to get a square cut and removed the just the foam leaving the canvas intact on the other side. Then I cut an X pattern in the outer canvas, and wrapped and glued both the inner and outer canvas over the newly exposed foam to seal everything up.


The picture above is the door frame setting in position with the foam removed and the back canvas uncut.

Nice!

Good suggestions! I'm planning on cutting out the door and windows after both sides are skinned, primed too I guess. I found a source for used camper windows and doors, reasonably cheap, which I plan on going to get some next weekend. I'm hoping for some jalousie windows.
I am still reading and not much working although today I plan to sand and prime the trailer chassis.

I use a razor knife on the canvas, for foam nothing I've tried beat a a hand drywall saw