Help turning Mica pearl acrylics

[DigBaddy72]

I recently ordered 18 of the mica pearl pen blanks from PSI: https://www.pennstateind.com/store/PKXMP96.html

I am having some difficulty with blow outs and chipping while turning.

I have turned acrylics before but they "ribboned" nicely when turning. These turn like chalk! Very dusty and no "ribbons" while turning.

I am turning at about 1500 rpms with Carbide tools.

Anyone have any suggestions? Turn faster? Slower?

Thanks!
https://www.pennstateind.com/store/PKXMP96.html

 

[jsmithmarcus]

I use a sharp (very sharp) skew and take light slicing cuts. Once you get the size and shape good just wet sand with MM and polish.

 

[turncrazy43]

Keith, I have turned some of those blanks using carbide tools. They are very brittle and can blow out easily. I have found that very sharp tools and light cuts is the way to go. Take it slow. I have found that alumilite blanks are better to turn, but dusty as well.
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[thewishman]

Turn up the speed and cut in from the outside edges. Max speed will make turning them easier.

 

[DigBaddy72]

Thanks everyone. I'll be trying these suggestions later tonight or tomorrow night.

 

[Ted iin Michigan]

Those are some of my favorites - and darn good sellers as well. I agree that sharp tooling plus real light cuts is the key. I read once that nearly all turning difficulties can be cured by sharpening your tools.

One of my additional strategies is to turn a wee bit oversize with a skew (a bit larger than you otherwise would) and then sand to final size - I use 150 for that. Then sand and polish normally.

 

[The Falcons Quill]

I love the way these finish, regardless of the difficulty, they have great depth. I usually rough shape and leave a good bit material left and then start with 60 grit sandpaper and my shaping tool. It takes some time to get the marks out it leaves but better than a blow out.

 

[Quality Pen]

Definitely turn at the max speed your lathe can... sharp tools too!

But even still, these mica blanks can be some of the worst to turn. I've found no other blanks that have inherent pits like these. Not all, but it happens! They are also the most sensitive when drilling when it comes to "blow outs."

So, are they good for a new turner? Yes and no. It's thrilling to finish one and see the beautiful pen they make. But at the same time, it's in a whole other league as far as difficulty compared to, say, acrylic acetate.

 

[jj9ball]

I use a gougle with an ellsworth grind and cut with the side of the tool taking really light passes. They make beautiful pens .... just don't drop em. I had customer who dropped one on concrete and it shattered.