Help making "wooden" enclosure for BPs

[Kimberbee]

I saw a lot of people on other sites saying to use old furniture as the basis for a wooden enclosure (perk of which being that it holds heat better than a glass tank, which is what I need in all honesty) but I want to make 100% sure that I'm doing everything right before I move my ball python I have into it, as well as make sure its safe for the one coming in October!

These are photos of my idea, which was to turn a dresser with a "cubby" top half into a two story snake enclosure, the top and bottom being separate of course. the back is plywood, and the front will be sheets of Acrylic once I get some.

https://imgur.com/a/f0mBUhs

But my questions are these:
1. What should I seal the wood with? my middle plank I made is not finished at all and I want it and my snake to be protected, but I'm scared of chemicals left over. I saw someone say Epoxy, but I want to be sure I get the right one. That, or should I simply lay a sheet of acrylic?

2. What is the best way to get heat to them? Again I have heard many things, some of them consisting of cutting out part of the bottom for a heat mat, but seeing as the bottom for one is top for another, I have to think of something else. Someone also said to stick the heat mat to a tile and just set it inside, or use heat tape/cable. I'm looking for thoughts on the best one and/or how I should put it.

3. Substrate! Someone told me CEDAR, which I thought for a fact was bad for reptiles! Needless to say I'm not going to use that just in case... I will have runners to hold substrate in, and I think I want to do coco fiber, but I wanted to know what grade, if the smallest was best or if the bigger chunks would keep them from ingesting?

Any and all help is welcome! Any MORE tips other than what I have asked is also more than appreciated!

[eminart]

That shelf is made of MDF, which has a coating on it to prevent moisture from getting to the wood. That's great, as long as it works. Because if MDF does get wet, it's ruined. So, assuming you aren't going to pour water into it, it can work, but you'll need to seal up all the seams with silicon or something similar. As for the unfinished wood shelf, you can seal it with polyurethane. Epoxy is better, but it's also pretty expensive, as is acrylic sheets.

It sounds like you have some suggestions for the heating. People do use covered heat mats inside the enclosure, although I've never done it, so I can't comment. Another option is to put ceramic heat emitter (bulbs) in fixtures screwed inside the top of each enclosure. They'd have to be covered by a wire cage to prevent the snake from touching them.

Substrate - definitely not cedar. For ball pythons, the coco fiber based stuff is going to be better than aspen due to it holding humidity better. Another option is cypress mulch. It all works. I wouldn't worry too much about them ingesting it. You'll have a difficult time finding anyone who has first hand experience with problems from ingested substrate.