Okay, so I'm scratching my head on this one. I'm mid build, laying out some cut marks by electro etching (as I described here Obscure tools, tips & tricks of the trade
) on some MHS sleeve. And it's a no go. no matter how much I try etching the sleeve, it makes no mark at all. And yet, if I try the same trick on a) regular MHS pieces, b) 6063 aluminium tubing, 2) 6082 aluminium bar, it etches easily.
Which leads me to draw only one conclusion: there's something insulating the MHS sleeving. I got out my multimeter and what do you know, the outer diameter just isn't electrically conductive at all. the inner diameter conducts fine, but the outer one does not.
I can't wrap my head around that at all. I mean, given the number of finishes (etching, powder coating, anodizing) that use electricity, why on earth is the sleeving material coated in something insulated?