Help ? Please? Finish for a polyurethane and sand layout?

Ok so I need help , I started to layout a landscape for my tank and halfway through realized the method I chose is not optimal for my bearded dragon. ( actually a rankins but so similar it's applicable to any beardie enclosure) I am now in a dead end looking for a Clear( preferably matte) hard coat that I can apply directly to great stuff expanding spray foam ,( the pond and stone version, if it makes any difference) also to note is that I layed playsand into the gs expanding foam as it was curing ( and the majority of The sand stuck well )so I have a look I am very happy with and would rather not completely cover with some opaque coating and be at the exact same place I am.I guess I am essentially looking to skip a grout or drylock layer .....is there even a product out there for that or am I searching in vein?
If you get the gyst and have a suggestion no need for further reading but I will add pictures to Help visualize my goal here.

Here was my plan
I was going to make a great stuff ( pond and stone version , since it was fish safe without mortar) expanding insulation foam spray sealant landscape for my teacup beardie ( aka rankins dragon). Here comes the catch, I want each piece to be easily removed for cleaning, escaped feeders and of course emergency relocating of stuck/stubborn/sick beardie. So I delved deeper into my originally devised plan and coated each section with wax paper.
This only shows the tank wax papered but you get the idea( I wax papered everything I was using for landmarks) . SO I went at it with my new can of gs expanding foam and approximately 4 minutes after spraying it I sifted play sand over it and occasionally pressed it down in certain places . below is what I got from one can and the water dish in the foreground of the tank so I vastly underestimated the number of great stuff cans I needed.( turns out to be around 5 cans)
Kept on going as I had and ended up here, then here, then there.
This was all in a week and this is where I am stuck so I placed most decor back into tank for this photobomb ( BIG HEADS UP FOR ANYONE WORKING WITH EXPANDING FOAM is that it shrinks after the initial expansion. We managed to deal by slicing off ill fitting pieces)

Sorry I'm going to have to post my photobomb as a response to this post since I'm not going to Chance rewriting and documenting this for the third time.

So that was my photo bomb I said I would post as a comment . And then. Here are 2 different backgrounds any preferences? I like the blue one although I don't think it's as pretty as the greener one , but it seems more natural to their habitat.

Get rid of the sand.

Not an appropriate substrate for a bearded dragon to live on see this for information on their actual habitat in their natural range (very little sand)…. viewtopic.php?f=34&t=244236


Regarding the expanding foam , you need to coat this with a concrete like coating so it's got a surface that is hard enough not to be wrecked by the dragon's toe and finger nails , else you will soon have bits of PU throughout the tank which are very serious ingestion and impaction risk.

You will also need to ensure the material has given a LONG time to outgas at basking temperatures before installing a living dragon the tank else you will end up poisoning the dragon.
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710027437.pdf suggests up to 1% of the mass will outgas , and since a reptile tank is a confined space , released by the PU will accumulate to very high / toxic concentrations unless you take steps to seal the surface of the PU with an impervious coating.
The MSDS for polyurethane foam …. is nasty stuff …. and outgases same really nasty fumes / gases / vapours.
https://docs-europe.electrocomponents.com/webdocs/07c3/0900766b807c383b.pdf

kingofnobbys":1c75mnkc said:

Get rid of the sand.

Not an appropriate substrate for a bearded dragon to live on see this for information on their actual habitat in their natural range (very little sand)…. viewtopic.php?f=34&t=244236


Regarding the expanding foam , you need to coat this with a concrete like coating so it's got a surface that is hard enough not to be wrecked by the dragon's toe and finger nails , else you will soon have bits of PU throughout the tank which are very serious ingestion and impaction risk.

You will also need to ensure the material has given a LONG time to outgas at basking temperatures before installing a living dragon the tank else you will end up poisoning the dragon.
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710027437.pdf suggests up to 1% of the mass will outgas , and since a reptile tank is a confined space , released by the PU will accumulate to very high / toxic concentrations unless you take steps to seal the surface of the PU with an impervious coating.
The MSDS for polyurethane foam …. is nasty stuff …. and outgases same really nasty fumes / gases / vapours.
https://docs-europe.electrocomponents.com/webdocs/07c3/0900766b807c383b.pdf

Click to expand...

Thank you for your quick response Kingofnobbys. I think you have misunderstood my post. I have absolutely no loose sand in this build. ALL sand is thoroughly bonded to or embedded in the expanding foam and can not be removed even with vigorous rubbing . I have a Portland cement cured tank for another animal and don't want to do that for this tank that is why I am looking for a different way to hard coat this build but still hold the natural sand details.
Also the discussion board on actual bearded dragon habitat that you attached is great you would probably really benefit from reading it. You don't seem to keen on reading though so here is a picture of what the forum means when they say" most pagona dwell on a dry Sandy clay"
That is actually a gravid female rankins dragon found in (central North western? Not sure on terms over there used to describe different areas ) queensland defending her home.
The last link you added to your post was spam so I wasn't sure on the validity of the nasa pdf you linked . I'm glad I read it , because now I know that what I am using is pretty much safe to send into space ( although I don't plan to send my rankins to the moon) . It makes me feel a lot better to know that if I heated the enclosure at 125°c ( 257°f) for 24 hours it Will have only outgassed .01 but of course those temps would bake my beardie alive . So at his highest enclosure temps 110°f it would outgas less than .004 not to mention it wouldn't stay at that heat for more than 12 hours and the small bit that would actually be close enough to the heat would outgas less than .4% is safe .
But although that's all great to know it still doesn't give me any suggestions of a hard clear (matte if possible) coating to apply directly to the sand embedded foam to help strengthen it and increase the ease of cleaning it. Again any ideas ? Does a product like this even exist ? anyone have any experience with something similar ? Maybe like a zoopoxy that's clear ?

Well to be frank
I'd have to change my name

Bump ?

I'm doing a build with polystyrene and grout. I used the matte finish mod podge to seal it. I did 5 coats along with sand.

Drizzzt5":2qmbhbns said:

I'm doing a build with polystyrene and grout. I used the matte finish mod podge to seal it. I did 5 coats along with sand.

Click to expand...

But i am skipping the grout so does it seem like the mod podge by its self is giving it a rigid rock like hardness or is it the grout creating the harder fealing?

I have tested gorilla wood glue as a sealant for this and it's not as matte as I'd hoped and not rock hard like I'd hoped but it is hard and safe. I think this will do the trick.