Acrylic, Plastic and Resin Pens - Turning Coffee and Cream -  October, 2010

Well here's something new - acrylester with embedded coffee beans.  Looks like a real pleasure to deal with and the only reason I'm making the attempt is because I have a brother who works for Starbucks.

I decided to read the instructions first, this time.  They say these blanks are only intended for experienced pen turners, which I suppose is their way of saying the potential for failure the first time around is pretty high.

The coffee bean blanks cut clean enough and there is a distinct aroma of coffee beans in the air.

Plenty of room to work with here but use some caution.  Pushing through a coffee bean is much easier than pushing through acrylester.

These are cut down to size but the ends are not milled.  I don't trust those embedded coffee beans so I think fortifying them with some thin CA glue is the right thing to do.

Milling goes quickly and when you get close to brass, check carefully because it is hard to see the exposed brass through the acrylester pieces coming off.

Glue those ends one more time with a light coat of thin CA glue.

Lightly mill the coffee bean blank ends one more time, just enough to get rid of any excess CA glue.

Assemble the pieces and mount on the lathe.  Note:  If you haven't miked the bushings in a while,  now would be a good time to do so..

Initial bean blank turning is going well.  No coffee beans flying out or anything,  Lathe speed is high,  around 1800 rpm.   I found out from my last go-round with acrylester, that if you get the speed high enough and ensure the back of the tool lays against the blank,  the plastic softens from the heat and comes off in ribbons, rather than chips.

Oops.  Failure analysis indicates that I caught the tool on the edge of a bean, thus tearing out a chunk.   I should have reinforced the entire blank with thin CA glue, which I did not do.  Must've been getting a little cocky there.

It's always a good idea to have a spare or two available.   I am starting to think too, that this is not entirely my fault. The tail stock on this lathe sports a live center and one thing I have noticed is that I tend to pick up a little vibration at that end from time to time, as in this case.  What I've been doing is swapping the blanks to the head stock end to do the detail work.  It does seem to help in that not so many blanks blow up.

So much for that theory.  I tore out a much smaller chunk and this can be repaired.  The crack went right through a number of beans.

This is looking OK.  Finally.  These are ready to come off the lathe in order to do a final light hand milling on the ends.

Scratch the light hand milling part.  I did a light hand milling and tore out a coffee bean.  Fire up the lathe and lightly mill the ends one more time.

Ok,  these are good to go. I am going to finish these using my partial CA glue finish technique.

One thing about non-specific designs is that it affords you some flexibility in masking errors.  The piece I tore off with the milling tool is going under the pen clip.  The rest of it looks ok.

One Coffee and Cream Acrylester 7mm pen.

Coffee Bean and Cream Pen Blank Specific Notes: 1.  Turning this kind of pattern makes it appear as if there are hills and valleys when turning. It played havoc with my depth perception so I ended up feeling where I was by running my finger across the blank whilst turning to get a better perspective. 2.  The coffee beans themselves many times appeared to have small cracks in the center, where the acrylester did not fully melt in.  As I got closer to the finish,  I stopped several times and coated the beans with thin CA glue in order to prevent them from cracking out. 3.  The instructions were right in that you do need a light touch.  The coffee bean blanks will turn down very fast with a sharp tool but you need to ease up when you get close.  If you have ever worked with spalted woods, you know what happens if you are not paying attention and hit a pithy area.  What happens is you can drive your tool much further into the piece than you had planned, and this happens in a micro-second.  Think of the coffee beans as pithy areas and treat them as such,  This includes their reinforcement with CA glue. 4.  The instructions also said that with a true CA glue finish, you can no longer smell the coffee in the beans.  I don't know if that is a fact or not, but I do know that using the hybrid finish I like,  there is no doubting the pen is constructed in part with rather pungent coffee beans. 5.  I noticed in spots where the acrylester was getting a little thin, you could see brass if you held the pen up to a light.  Next time I would coat the brass tubes with either a black magic marker, or white - if they make such a thing. Have fun!