I'm noticing that when I turn really hard woods, even with brand-new and very sharp carbide bits, sometimes I'll see these long scratches on the surface. Often they'll only become apparent once I've started sanding, and no amount of sanding seems to be able to mitigate or remove them. Do I really need to re-surface the bowl with a chisel?
I pretty exclusively use Easy Wood Tools (carbide-tipped) since I don't have the space for a sharpening system. Generally, I use the circular bit (which they call the finisher) for roughing, then try to get a fine surface finish with a square or radiused-square bit.
I'm attaching some pictures that show the scratches I'm talking about.
Since my tools are very sharp, and I'm seeing the scratches no matter what speed I set my lathe at, I'm wondering if they're happening because the speed at which I move the tool along the wood is slightly inconsistent - could this be the case? (I find it really hard to move the tool at a super-consistent speed, as it seems like there are "slippery" and "sticky" parts on the surface of my toolrest).
Any tips or tricks would be much appreciated - I note, this doesn't seem to happen nearly as much on softer woods like walnut.