Turning acrylic pens

[Chips n dust]

Can someone provide me with the do's and dont's when turning acrylic for pens? ie: How to polish, speed for turning etc. I have a blank and am anxious to try it, however, I have only turned pens from wood in the past.
Many Thanks.

 

[melogic]

I have done several Crushed Pearl pens. I use the sanding pads from PSI and follow the instructions that come with them. It is basically wet sanding through all of the pads and when you get done, you have a glass like finish. It's not as bad as you would think. Here is the link for the PSI sanding pads http://tinyurl.com/5o7hr

 

[timdaleiden]

Cut the blanks extra long. Acylics have a tendency to blowout a bit of the bottom of the drilled hole.

When I turn acrylics, I turn my chisels with the cutting edge "down", as opposed to when I turn the sharp edge "up" for wood.

I also wet sand for a finish with the pads, and then I use a bit of car finish swirl mark remover with a paper towel.

 

[Rudy Vey]

Drill carefully, clear the chips often, I actually drill wet, i.e. I wet my bit with water, applied with a a small (1") brush that I hold on the spinning bit.
Take it easy when you turn it, don't try to hog off material. I start with a gouge, finish turn with a skew and then wet sand from 320 all the way to 2000. Wet MM is also a possibility. Check often if the sanding marks from the prior grit are gone and clean off the residue from sanding. Finish up with a automotive rubbing compound or the Novus polish. When everything is properly done they shine!!!

Important: since most acrylics are semi-transparent, color the brass tubes before gluing them in. Some guys use spray paint, and I use Sharpie Permanent markers and "Uni" paint markers, also from Sanford.
Works well for me. Nothing is worse than having the brass tube visible through the acrylic material.

When assembling the pen parts make sure that they are not tilted, as this may lead to splitting of the acrylic when pressing them in.

Rudy

 

[melchioe]

I simply turn the plastic just like wood, although it stinks a lot more... so dust collection or simply ventilation is important. I'll echo Tim and Rudy - drill slow (it'll take longer than wood to do a clean job), clear more often than with wood, and if you don't drill wet, let it cool partway through each section. If you don't let the bit cool, you might get some melting. Use a nice sharp bit, too.

The bottoms of the blanks can very easily blow out (even if drilling into wood backing) so what I do is NOT trim to length at first, cut the blank into lengths for both tubes with generous extra on each end, and drill from the center-band edge out. That way the blowout is on the ends you trim off afterwards. Also, drill VERY slowly at the ends, this can minimize the blowout.

I sand just like wood, using micromesh all the way to 12000. I tend to use a nice light touch, but I stay with each grit longer on acrylic than I need to with wood. I sand it dry, but I wipe off the MM pretty often while sanding it.

And finally, Rudy's comments about color are critical and bear repeating. I like markers, as they do not add to width and do not appear to affect glue bonding. But let them dry real well before gluing.

 

[Chips n dust]

Many thanks for the tips, I will let you know how my first attempt turns out.
Trevor

A day without sawdust is like a day without sunshine.

 

[tomy2]

I by no means am an expert at acrylics...heck I only made 2 so far. One thing I can say is make sure your tools are sharp....also wet sanding seemed to be the way to go. I have not tried car wax yet....

 

[bigdove]

Tim, what advantages do you find by turning the chisel down?

 

[timdaleiden]

Originally posted by bigdove
<br />Tim, what advantages do you find by turning the chisel down?

My experience has been that when a very sharp edge is applied at a sharp angle to acrylic material, it will rip away large amounts of material unpredictably. I call them mini-blowouts, but no matter what I call them, the end results are bad. For roughing out the blanks, I use my chisel in the normal way, but once they are round, I flip the chisel over.

Shaping takes a bit longer this way, but I get nice long strands of material coming off, rather than chunks.

Other people may have other methods.

 

[melchioe]

I agree with the sharp angle thing - I find it works better with shallower angles. I don't turn them over, though.

 

[jwoodwright]

You must have sharp tools. I go "scary sharp". After the grinder is the honing on glass with wet/dry paper. For the gouge, I have paper glued to paint stirrers. The correct angle will be evident when the material ribbons off. You'll see the blank go from cloudy to clear. Wet sand and polish. Polish has fine abrasives that make scratches so fine we can't see them.