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Hey I'm new to the site and was hoping you guys could offer some advice and some do's and don'ts

I'm wanting to build a few things (since i like to do that kind of stuff) and i was wondering if anyone here has used high build foam to construct anything my main question is... Will it be safe for my tigers and my gecko more concerned about the tigers than the gecko. Also, if this is a good idea what kind of paints should I use that would be safe for them and how long should I let everything dry to be non toxic. I appreciate the input if this isn't a good idea just let me know i would just rather make something i like than settle on buying stuff i'm just okay with at the pet store.

the main pieces I want to build are a cave with a removable top for the gecko (for shedding) and a few islands for our tigers we are redoing our 75 gal so that it has moving water. We're using a turtle beach that was giving to us on one end and are wanting to build land structures with water around them.(this is strictly for our salamanders we keep our gecko in a seperate enclosure.

I'm glad that the gecko and salamanders are in separate tanks - you had me worried when I started reading the post.

For tiger sals, they should have a substrate that they can dig into. Since the tank is large, you could have a water feature too, but I'd recommend making it a mostly terrestrial tank.

Sorry I'm not familiar with high build foam. People have used Great Stuff foam. It is safe, but it tends to suffer shrinkage over time.

Make a fake rock cave/basking spot for a reptile cage.

Found that while searching on this stuff "The Great Stuff" worked Great i've got mine about done haven't had a whole lot of time to work on it and it's just a test run. It's a cave for our gecko going into a 71 gallon tank i constructed last night as it's way to big for the tank i was going to keep it in. Sorry don't have any step by step pictures. ATM, it's got it's last coat of shellac on and i'm going to let it set till late tuesday before I introduce it into the tank with a Bahaman Anole. If that works out our blazing blizzard gecko will be introduced into the new tank with the cave and if it works out Ike and Scooter we get some new hides and land structures using this formula.

Materials:
Stiff blue foam (not sure exactly what it was as i found it in my garage from something i did years ago)
Hot glue
Great stuff Expanding foam
1600 grit unsanded grout in brite white (look for a more natural color is you don't plan on painting)
Acrylic Paint
Shellac

(Sorry if you feel like that's animal testing. I don't feel safe using it with my gecko or tigers and don't want to find out it's not and lose one of them. I've been wanting a Anole just cause it's a daytime critter and is very active.)

here's some pics of it in grout a base coat i mixed up then in tan with clear and one of the brown anole

looks good!
you may want to have someone else chime in on the grout before you put it into your tank, i remember hearing something in a thread about slate/tile substrate that grout can mess with your water conditions.