Good morning,
I have the XL reptibreeze and just purchased 2 pvc boards i wanna replace for the side and back. I read you used 1/4 self tapping screws is it just that size in the screws used or another length to the 1/4”. Also i take it that i would need to remove the spline for the sides being removed just wondering how to screw the panels to the cage frame. Hope this all made sense.
Depending on what tools are at your disposal and your skill with them...
If you're modifying the Reptibreeze into a hybrid, I think you'll have to replace both sides along with the back, and do something about the front as well (acrylic or window insulation) except for a small intake at/near the bottom of the front/door.
You can attach the PVC panels in (at least) a couple of ways—inside or outside of the screen. Removing the screen is optional, but the panels will still have to be attached to either the inside or outside of the remaining frame, and cut to appropriate size to do whichever.
Length of screws will depend partly on the thickness of the PVC panels. Personally, I would use stainless steel sheet metal screws as long as the thickness of the material
plus 1/8" to 1/4" long—enough to get past the taper of the point of the screw for holding.
You'll also need to decide on the type of screw head (pan head, countersunk, hex head) and whether you want to add washers for added strength so they won't poke/pull through the PVC. Some screws come with integral rubber washers to help seal against leaks; they'll cost a bit more.
The PVC could also be attached
without screws by applying a thin bead of silicone and clamping/pressing the PVC to the frame. PVC will have to be cut large enough, and clamped, or disassemble the enclosure so you can work flat and press with a rigid cover sheet (e.g. plywood) and weights. You might apply silicone anyway to seal against leaks, so it'd be killing two stones with one bird.