I went to loews and saw a tub that measured about 34.5L x 16.8W x 6H and found a shelf that fit it perfectly only thing was the tub had like these 3 raised areas like in those aluminum roasting pans...
Where were these raised areas? On the bottom of the tub or on the lip that runs around the top? Sometimes tubs with locking handles have a recessed area on the upper lip of the tub. Is that what you're talking about? That can be a problem for security but those gaps are easily filled in.
If the raised areas are on the floor, this is no big deal. I prefer tubs that are totally flat but this is not common.
I do try to avoid tubs that have four or six raised circular "feet" on the bottom, but even these will work.
If you found a precut melamine shelf that fit over this box perfectly (hopefully it's at least 1/4" longer and wider) then you should have an easy to build rack. I would not drop down to the 32 qt. tub for an adult ball python.
Im looking to build something simple as I only have a drill and circular saw and dont have much experience building.
You don't need much more than this. I do recommend a carpenter's square, an edge-guide to run the saw against, some clamps to hold the edge guide, and a decent pre-drill/counter-sink bit.
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Current snakes:
0.0.1 Gonyosoma oxycephala - Java locale (green)
2.2 Gonyosoma janseni - Seleyar locale (all black)