Blank identification

[MPVic]

I received this blank as a gift - there was no label on it but it definitely was cast.
From the photos, I hope you can see the very fine "cracks" at the left hand end of the blank. Any ideas about the material? Are those fine cracks a defect? The right hand end does not have these.
Thanks in advance.

 

[Mortalis]

What I see is a tool that is not cutting well. This looks like the tool is rubbing, not cutting and causing the stress cracks. IMHO. I do not know what type of a tool you are using. If you are using a non-insert tool look carefully at the tip underside and you will most likely see a shiny area at the cutting edge. That would be the rubbing that is causing that. If you are using an insert type cutting tool then you could still have a worn edge that is actually acting like it is cutting above center and again causing a rub.
Acrylic is very temperamental about the the cutting edge being being very sharp.

 

[magpens]

To me, the blank looks like it could be a cast Alumilite blank. . Alumilite is one of the nicest blank materials and should be a very easy turn.

As for the "cracks", I would tend to agree with the above assessment ... stress marks resulting from the way the tool was applied.
Mind you, I have never seen such marks on Alumilite, but I have "made it happen" on the common "acrylic acetate" (or AA) blanks.

 

[qquake]

Look like chatter marks to me. How sharp is your chisel? The blank looks stunning, I hope you're able to save it.

 

[J_B]

Second the motion on what Jim stated above. I do not see these as stress cracks. These chatter marks occur when I get too aggressive with my tools plus not being sharp enough and only happens to me on resin. They will disappear with very light cuts then your polishing process.

 

[qquake]

I am the king of chatter!

 

[Fred Bruche]

If you got it from someone I know (looks like it ), it should be a Liquid Diamonds epoxy blank. it's a bit more temperamental than alumilite, sharpen your tool or if you are close to the final size you could always use sandpaper (150 or 220) to bring it down.

 

[qquake]

I've gone as low as 100 grit.

 

[MPVic]

Right on!!!! Thank you to all who responded - it was definitely a dull tool issue. After putting in a new carbide cutter the stress cracks were easily removed. Thanks for sharing your experiences - it's what makes us all better craftsman.

 

[qquake]

Do we get to see the finished pen?

 

[MPVic]

Do we get to see the finished pen?

Absolutely!! Just got a bunch of other stuff going on this coming week so may be a bit.