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Ever seen those pen blanks with coffee beans in them?

I’m hoping to make a pen like that for a relative and wondering if I can cast my own blank using epoxy.

Would that work?
 

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There is a whole lot of information and support for making pen blanks at:
https://www.penturners.org
https://www.penturners.org/forums/blank-making.178/

I have commercial coffee bean blanks. These:
https://www.rockler.com/coffee-and-cream-inlace-acrylester-pen-blank

Frankly, it is the most challenging blank I have seen. Inlace acrylester is brittle and difficult anyway, but I have turned enough of them that I get good results and they don't concern me. However, the embedded coffee beans raise the challenge to another level. You will need to bring your very best sharpening skills and have the sharpest possible tools. Turn with the lightest possible touch. You will want to stabilize with thin CA very often as you turn. That will help reduce the number coffee beans from popping out as you turn the the blank, but it won't eliminate the problem altogether. When a coffee bean pops out, you must stop the lathe and hunt on the floor for it so you can glue it in with CA and then resume turning.

When you're done, there is the question of finish. You really want a CA finish to protect the exposed coffee beans from dirt and wear. Otherwise the pen gets a dingy look over time. The problem is that the CA finish seals in that wonderful coffee smell that the pen blank had.
 

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You can, but its not quite as simple as "mix epoxy, add coffee"

First and foremost, epoxy doesnt stick to oil. Coffee beans are oily. Hopefully you can see the problem there. Nothing insurmountable, you just need to de-oil the beans as much as possible. A soak in acetone should do the job pretty well, youll just need to change the acetone a time or two to make sure as much oil as possible is pulled out. If the beans soak in the acetone for an hour or so and the acetone looks like coffee, change it out and soak em again

Ideally, after de-oiling you would resin-stabilize the beans. Maybe not strictly necessary, but personally i wouldnt bother trying to resin-cast any non-stabilized natural material, too much risk that could be easily avoided, though resin-stabilization does add an extra step and need a bit more tooling. Still though, you dont want your coffee beans to start molding or decomposing in the block

Actually casting the epoxy is going to be both the simplest and most complex part of the process. Most importantly though, make sure youre using an actual casting epoxy, using an epoxy (or any resin really) thats not designed to be cast in large sections can cause a dangerous buildup of heat that in the best case scenario will boil your epoxy and ruin the entire project, in addition to filling your shop with toxic fumes. Worst case is something catches fire. Anyways, youll need a casting epoxy, a mold box, and a plan. Coffee beans have a specific gravity of .53g/cc, something like Smooth-On EpoxAcast 690 casting epoxy has a specific gravity of 1.1g/cc, and this is all a very over-technical way of pointing out that coffee beans float in epoxy, so you need ot think of what end result you want and how to accomplish that. If youre wanting to have a smattering of beans floating in epoxy, youre going to need to cast in layers, that way all the beans dont just float to the top. If you want a densely-packed block of beans, youll need to be sure to weigh down the beans and pack them in the mold while the epoxy is curing

Beyond the floating issue, you need to be concerned about bubbles too. Ideally you would vacuum degass the epoxy before pouring it into the mold, and cure it under pressure in a pressure pot. Doing it that way gets you crystal clear castings, but does need equipment. Lacking the equipment, you can get decent results by using a resin with a long cure time(3+ days) that willl allow the air bubbles to float out, but the longer the epoxy is liquid the more you have to worry about the beans floating out, which goes back the the "plan it out" paragraph up above

Course, you can ignore all this, dump some random epoxy and some coffee beans into a mold, and youll probably get a block of epoxy with coffee in it, but dont expect it to last very long
 

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$9? hardly worth the effort to cast your own
If all you want is one coffee bean pen, then I agree. I would recommend ordering at least two coffee and cream blanks and have spare tubes for the pen kit on hand. If you have never turned inlace acrylester, then you may want to order three. Be prepared for failure as you learn. Very sharpest tools with the lightest touch, and stabilize as you turn.

I buy them at Rockler. I walk in the store and buy them off the shelf. It saves on shipping:
https://www.rockler.com/coffee-and-cream-inlace-acrylester-pen-blank
They have Woodturningz stickers on the actual blanks. Going there, I found these in cream (same as above), cappuccino, and mint:
https://www.woodturningz.com/Inlace-Acrylester-Pen-Blank-90-Coffee-and-Cream
https://www.woodturningz.com/Inlace-Acrylester-Pen-Blank-92-Cappuccino-Coffee
https://www.woodturningz.com/Inlace-Acrylester-Pen-Blank-94-Mint-Coffee

It begs the question, what were the missing or discontinued numbers 91 and 93? Pumpkin Spice Latte? Salted Caramel Mocha Frappuccino? :)

As I said, my first inlace acrylester blank took three tries before success. I have not had any inlace acrylester failures since then. Some inlace acrylester blank descriptions at Rockler say "easy to turn." Don't believe it. Here is an example, actually the one that took three tries:
https://www.rockler.com/inlace-acrylester-pen-blank-holographic-black

Making your own pen blanks is a fun hobby - another rabbit hole to follow. There are lots of forums, YouTube videos, etc. to get you going. I have friends who make blanks and share them or sell them. Some people go professional and are quite successful at selling their premium blanks. If all you want is one coffee bean pen, then I would not try to make it yourself.
 
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