Let's give you a hint, here.
X-raying anything made of thick metal instantly puts limitations on what you can achieve.
If you're trying to find cracks in - ferinstance - the frame or an engine casing, there are fluorescing-dye methods which would/could be far more suitable.
If you're talking 'bits' are they bits which can be removed easily? What size? Are you asking someone to spread oil, petrol, road grime, and battery acid all over their nice clean equipment?
Narrow it down a bit, eh?
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