I haven’t had reason to try epoxying buoyancy foam before, but I’d imagine many people that have done so didn’t require the extra strength and abrasion resistance of including a fibreglass or other mesh, particularly given
- the extra work and cost required
- the additional weight on something which is supposed to be a source of buoyancy, and
- the extra volume, which makes it harder to fit a pre-cut piece of foam in a fixed size location.
Note also Rusty’s response here, which suggests that coating the foam is more for stopping water ingress at depth than protecting it from impacts or abrasion. I’d imagine the intent is for a protective cover like our BlueROV2 fairing to still be used, in which case the coating shouldn’t really ever be at risk of getting hit or rubbed against something rough.
Perhaps some others in the community have some additional insight