Hi again, and thank you for reading. I am in the process of my current build at the stage of ready to radius the newly slotted blackwood fingerboard . I have in the workshop, Stew Mac radiused fret levelling 200mm timber blocks in good condition, one with the 12" radius I need. Do I really need to buy a 540mm long aluminium 12" radiused beam to do a good job ? I would be using a jig with 2 parallel guides to do the sanding in either case. My rationale is...if the 200mm timber block is not distorted along its length in any way, then as long as I maintain equal pressure on the 200mm/12" long block for the down and back strokes, there should be very little difference to using a 550mmx 12" aluminium beam in the same manner. And I can check so in the initial stages with a radius gauge. There's also the cost of almost $200.00 to buy and get an aluminium Stew Mac one to Australia. Happy to pay that if there will really be a noticeable difference to the end result.