Silcata injury

Question
So my 12 yr old silcatas brain is telling him to dig. We have an Acre of land in southern California with lots of grasses for him to nibble. When we find a tunnel we fill it. Yesterday he started a tunnel next to my nieces playground. Specifically underneath the wooden climbing wall. I think he got himself stuck and forced his way out at some point. When he did so, he scraped off 2 domes off his shell. I found him right after. One dome had been injured last year when his first tunnel caved in. That being said. His shell is down to the white surface. He is still eating and being his ornery self. We did a soapy water test to make sure the shell wasn't punctured. It wasn't. After his first injury the vet told us to use Apoxy to if we felt he needed it (like a shell bandaid) and said that when he gets shell injury's that are severe he uses fiberglass sheets to protect it. I'm not trying to avoid a vet bill, but does this sound like a good treatment? Or should I just leave him alone and let it heal?

Answer
I think you mean "sulcata", and tunneling is what they do naturally. This is their nature, and I hope you knew that before you got one, because it's not going to stop. I hope you have 4x4 posts on the perimeter.

The shell being down to the white surface, means it's down to bone, and this is serious enough without being punctured. It's porous, and so you should watch what you introduce to it.

I'm also guessing you meant "epoxy"? Your vet is suggesting an old outdated method. Nobody who knows what they are doing use fiberglass anymore. It's irritating to tissues, the curing agents are volatile and toxic to tissue and for the tortoise to breathe, and it seals in any infection. No - this is not a good treatment!

I recommend a stiff rinse of the surface with saline, followed by a rinse with chlorhexidine gluconate or bactine. You may brush lightly with a soft brush to remove debris, but do not scrub hard or you will drive debris into the bone. Do not use towels that will leave lint or other debris behind. Let antiseptic rinse dry then apply a protective coating of antiseptic liquid bandage. Repeat occasionally as needed when the liquid bandage wears off. You may also alternatively apply a light coating of shell conditioner like Vitashell between using the liquid bandage. This may take a long time. Tortoises don't heal fast.