In answer to your questions my take is:
1) yes you do need a mandrel and when I started I made mine out of resin (kirinite or anything else I had lying around). It’s fine when you’re starting off and experimenting and it’s fairly easy to make a new one. Once you have the shape of it nailed down then you can make one in aluminium or preferably brass. Aluminium is easier to turn on a wood lathe but brass is very possible too. I made all my first brass mandrels on my wood lathe - just buy rod that is close to your desired finished diameter, or you’ll spend ages turning it down to size.
2) 3) 4) My advice with cutting anything on a lathe is to have the speed as high as you can that still feels safe to you, (your instinct is your friend here), and then use light cuts with sharp tools.
Always start from the edges and work towards the centre of the work to avoid chipping. This is very important.
The half inch HSS skew is my favourite tool as it’s very flexible. You can use it to slice, scrape and form. By ”form” I mean you can lay it flat on the tool rest and push it into the workpiece and it will remove material the same shape as the tool (we’re usually at the edge of the work here, not in the centre
).
By having it flat on the tool rest it makes it similar to a negative rake and it’s
almost impossible to get a catch this way.
So with something like kirinite I do the following:
1) forming - remove the excess by pushing into the workpiece at intervals along the tool rest. Start at each end and work towards the centre nibbling away a few mm at a time. This is a quick way to get close to the finished diameter.
2) scraping - then use it as a scraping tool to get the final shape and diameter. I hold it at the same 90 degree angle but now slide it back and forth across the workpiece rather than pushing it in. Again start at the ends and work in.
Tip - I have a slight convex curve from just beyond the middle to the heel of my skew. I still have a flat area creating a right-angle at the toe end. The best way I can describe it is a sort of elongated J shape and I only use it for pen turning. I use the toe end for forming cuts and the rest of the blade for scraping, as it’s less aggressive than having a straight edge all along. It works for me at least.
Cheers
Ash
