Plastic pen blanks -

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BeeAMaker

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Jan 30, 2017
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I have noticed that some blanks turn just fine, and others do not. (plastic)

All of them claim to be "acrylic" but, not all acrylic is the same composition. Some times I can turn a plastic blank just fine, then other ones will be cutting good then suddenly chip city! It is like I hit a "soft spot" and the tool just digs right it and send chips everywhere.

Is this a result of improperly mixed acrylic or possibly two different types of acrylic mixed into the blank? Sometimes it seems that one of the colors will be harder to cut than others in the same blank, almost like a wood with a hard grain and a very soft grain, like pine.

I know dull tools can dig in, but it seemed to happen worse just after a good sharpening. Just seems that there are some very soft veins in the blank, inconsistent.

I've got some 1/2 SS rod, handles and Carbide inserts to make some carbide tools. I have a feeling they will turn plastic better - thoughts?
 
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Skie_M

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You may experience the same issues with carbide tipped tools....

Keep the bits very sharp, kick the speed up a notch or two, and make light cuts with each pass.

Some types of acrylics are very chippy ... I know that there are some beautiful ones from PSI that chip like crazy, but look just gorgeous when they're finished. I'm told that they are an Acrylic Acetate, or AA.

The Lava Silk from PSI is totally different, and I've turned these several times. High Speed Steel as well as Carbide ... both make beautiful ribbons of material fly off these blanks, and I don't get chips unless my tools are dull or I'm being too aggressive.

Most acrylics you'll find fall somewhere in between these two.

I'll be turning my first home made blank shortly ... made it earlier today with some Alumilite brand Amazing Clear Cast. I won't post a pic here, you'll find it in the Bash later.

It appears that this stuff will be of the "easier to turn" variety.
 

its_virgil

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Jan 1, 2004
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Wichita Falls, TX, USA.
There are many many types of "acrylic" blanks on the market. Acrylic seems to be a generic term for all of these types of plastics. They all behave differently while drilling, turning, and polishing.
Improperly mixing: I don't think so.
Two different "acrylics" mixed together: Don't think so.

Thoughts on carbide for plastics: I am not a carbide tool fan for turning. I have several carbide tools and I rarely use them. I find no tool as good as a heavy sharp skew chisel. Just saying.

Do a good turn daily!'
Don

I have noticed that some blanks turn just fine, and others do not. (plastic)

All of them claim to be "acrylic" but, not all acrylic is the same composition. Some times I can turn a plastic blank just fine, then other ones will be cutting good then suddenly chip city! It is like I hit a "soft spot" and the tool just digs right it and send chips everywhere.

Is this a result of improperly mixed acrylic or possibly two different types of acrylic mixed into the blank? Sometimes it seems that one of the colors will be harder to cut than others in the same blank, almost like a wood with a hard grain and a very soft grain, like pine.

I know dull tools can dig in, but it seemed to happen worse just after a good sharpening. Just seems that there are some very soft veins in the blank, inconsistent.

I've got some 1/2 SS rod, handles and Carbide inserts to make some carbide tools. I have a feeling they will turn plastic better - thoughts?
 

jttheclockman

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Joined
Feb 22, 2005
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NJ, USA.
The skew is your friend. I have said this time and time again here. You do not need fancy rigs to turn any pen unless maybe if doing all metal pens but even that has been proven can be done on a wood lathe with wood tools. It is a small round object. Do not let it beat you. All acrylics are not the same but all that means is you have to approach a little bit different. Sharp tools and avoid heat, 2 major rules in pen turning. :)
 

its_virgil

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Jan 1, 2004
Messages
8,101
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Wichita Falls, TX, USA.
I love Acrylic Acetate..the real Acrylic Acetate...turns like a dream...threads exceptionally well and polishes to a brilliant shine. Not sure that what you are describing is acrylic acetate although it may be called AA. So many names, so many good acrylics, but so many not so good. Inlace acrylester or just acrylester blanks behave the way you describe. Way too much work when other acrylics are much easier to machine and look just as good.
Do a good turn daily!
Don


I know that there are some beautiful ones from PSI that chip like crazy, but look just gorgeous when they're finished. I'm told that they are an Acrylic Acetate, or AA.
 

BeeAMaker

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Joined
Jan 30, 2017
Messages
695
Location
Elkhart IN, USA
You may experience the same issues with carbide tipped tools....

Keep the bits very sharp, kick the speed up a notch or two, and make light cuts with each pass.

Some types of acrylics are very chippy ... I know that there are some beautiful ones from PSI that chip like crazy, but look just gorgeous when they're finished. I'm told that they are an Acrylic Acetate, or AA.

The Lava Silk from PSI is totally different, and I've turned these several times. High Speed Steel as well as Carbide ... both make beautiful ribbons of material fly off these blanks, and I don't get chips unless my tools are dull or I'm being too aggressive.

Most acrylics you'll find fall somewhere in between these two.

I'll be turning my first home made blank shortly ... made it earlier today with some Alumilite brand Amazing Clear Cast. I won't post a pic here, you'll find it in the Bash later.

It appears that this stuff will be of the "easier to turn" variety.

I plan to be making some myself. got my kit the other day. Need to make the molds first. I'm thinking of using 3/4" PVC pipe and making round blanks. I have some old paint pots that I will turn into pressure pots so I can put it under pressure to force the air out. I may try your method also.
 

BeeAMaker

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Joined
Jan 30, 2017
Messages
695
Location
Elkhart IN, USA
Inlace acrylester or just acrylester blanks behave the way you describe.

I looked the blanks up, that is exactly what it is, Inlace Acrylester.
I'll have to change my approach if I do theses again, I wasn't happy with how it looked after turning either, at least not what I hoped for.
Genesis Pen Blank #11 - Bumblebee - WoodTurningz

Alumilite Casting for wood turning recommends pressure casting for 100% bubble free.
 
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