[aerohead]

Knauf Insulation makes some great non-asbestos, high-temp insulation wrap.
I was involved in a Cleaver-Brooks high-pressure boiler-fed hydronic heating system for American Airlines Headquarters during the record freeze of 1983.
All the steam pipes were wrapped, then clad with an aluminum jacket.
These are commercial products. I don't know if 'individuals' can purchase from them.
Your friends the welders should have non-asbestos heat shields for close-quarters work. That material is local purchase.
And fiberglass welding blanket cuttings could be slipped between heat shield and ABS.