Ask HN: How can you retrain in a field requiring expensive equipment?

Suppose you come up with an invention involving a highly specialized, equipment-intensive field you’re unfamiliar with, such as plasma processing or high-temperature metallurgy. You’ve already consulted experts who agree the idea is plausible, but haven’t found anyone with the relevant expertise willing to help develop a PoC. How could you acquire the necessary hands-on skills to test the invention yourself?

I’ve considered switching jobs, postdocs, master’s programs, a second PhD, and shared research facilities. However, jobs and postdocs may require existing expertise, master’s programs may offer insufficient hands-on training, and independent equipment access can be prohibitively expensive (and even then, access alone may not provide the necessary training).

Are there any other realistic ways to retrain in experimental fields that require specialized equipment and can’t be learned at home?