Finishing a Polymer Clay Pen with CA Glue

There are many techniques for applying CA glue and I’ve tried most of them. I will show you how to do the one I’ve found to be most consistently effective.

If you haven’t already read my article on the prep work for applying CA glue to polymer clay pens, start there. The rest of this article assumes you already have a drill or lathe, mandrel of some sort, bushings prepared, and appropriate safety equipment.

This article assumes you have already sanded your pen barrel down. If it is not at or ideally slightly below the bushings, you will have issues with the CA.

Accelerator is best when sprayed 12-18” away from your work, which causes a problem for many polymer clay folks because we work in small spaces. The technique I discuss below solves for that.

The importance of bushing height

If you apply too much CA glue and go too far above the bushings, all the problems I’m about to discuss get harder to deal with — so pay close attention to bushing height, and consider sanding a bit below the bushings (or at least very very close to flush) so you limit how much CA is on the bushings.

Do not expect anything you do to fully prevent the CA glue from sticking to the metal: what it will do is make it easier to peel off at the end of your finishing session. If the CA is very thick this might be tough.

But even worse than having trouble getting the CA off the bushings is having trouble getting the bushings off your pen barrel. They usually stick a bit, but if you have a lot of CA above the height of the bushings, it’s more likely it is that the CA will break or fracture on the pen barrel when you separate the bushings.

In a later section in this article I show how to separate the pen from the bushings.

Preparing your pen barrel

Always make sure your pen barrel is dry, dust free, and sanded to ~800 grit. Toni recommends 800-1500, but so far I haven’t had any visible scratches at the end when I stop at 600-800.

You can use some 99% alcohol or denatured alcohol to clean the blank to make sure there’s no dust or oil left on it before proceeding.

If you haven’t already read my article on sanding pen barrels, take a look, it has some good tips.

How to apply the CA glue

There are many ways to do this. This is the one I’ve found gives me the most consistent and effective results. It also avoids getting accelerator all over my clay work surface.

If you prefer to explore other ways to apply CA, you can take a look at the videos I saved to my YouTube Pen Making play list, or simply search YouTube for more CA glue wood turning videos.

This is the video I learned from and is worth watching:

This method works by applying the accelerator with a paper towel or wax paper with accelerator on it before applying the CA, rather than applying the CA first and then spraying the accelerator on

March 2020 update: I found this was causing ridges in my glue from it curing too fast, and have switched to applying the accelerator afterwards, and it’s working much better. That said, this is the first method I used that really helped me “get it” in terms of effectively applying CA, so I’m still leaving my write-up.

The advantages of this method are:

  • You don’t need to get 12-18 inches back to spray accelerator on your barrels, which means you avoid spraying it all over your craft room
  • The glue dries quickly so your total work time is lower

The disadvantages are:

  • The CA glue is curing as you are applying it, so it will generate heat
  • The CA cures quickly, so you need to make sure you are alternating sides to start with the CA, so one side doesn’t get all the CA on it

Always start with thin to fill in the small scratches you can’t see before moving on to medium to get a thicker coat.

I do 4-6 coats of thin CA and then 1-2 of medium, but that’s very dependent on how well-sanded your barrel is to start (more scratches means you need more thin CA) and how close you are to your bushings (you don’t want to go too high above the bushings with the CA, as noted earlier.) Some do many more coats of thin, some many more of medium.

Regardless of how you apply your CA, keep these things in mind

  • If you are doing two barrels at once, apply to each barrel separately, refreshing your glue each time
  • Be careful about going back and forth too many times — you’ll learn to notice when it starts feeling tacky and stop. But before you learn, you’ll likely mess up your CA — it’s okay, just sand it down and start over
  • Always alternate which side you “start” from when applying CA, or you will get too much of a build-up of CA on one side
  • You’ll see a lot of woodworkers applying the thin CA directly to the barrel — I don’t do that because it requires two hands. I prefer to put it on a paper towel or wax paper
  • Always start with thin CA and do at least a few coats
  • If you are getting bumps in your CA you are trying to apply too much at once — do less each time and more coats total, I usually only do 2-3 drops each time
  • Fix bumps in your CA by sanding them off, going up to 400 grit, and then applying more CA
  • If you are getting white spots after spraying on accelerator, you’re using too much or spraying it too close

The point of applying CA smoothly andlearning how to avoid bumps is that you don’t have to do extremely low grits later to get the CA smooth. Too much CA sanding produces excess heat, which can cloud the CA, and also risks over-sanding to get through all the grits and removing all that CA you took the time to apply.

It’s worth practicing your CA application, paying attention after each coat or two to check to see if you introduced too many bumps because they will just keep getting worse if you don’t sand them back down.

Getting your bushings off your barrels

Even non-stick bushings will stick to your barrels via the CA glue. The point of non-stick bushings, and of the paste wax for regular bushings, is to make it easier to separate the bushing from the barrel, not to prevent them from sticking at all.

When removing your bushings from your barrel, remember that CA glue has very high tensile strength, but is much easier to break by shearing.

So don’t despair if you can’t pull your bushings straight off your pen — try to twist them or, if that doesn’t work, wiggle it back and forth in a sheared direction. You can also use a thin chisel to score the intersection between the barrels and the bushings to encourage it to let go without cracking on the barrel.

Your goal is to get the CA to let loose from the bushing but stay firmly attached to your pen without cracking.

If for some reason you do destroy your CA finish, you can always sand it down and re-apply it. I’ve done that three times on the same barrel when I was learning how to apply CA effectively.

If you are using regular (i.e. not non-stick) bushings, you may find it helpful to do a bunch of sanding first before trying to remove your bushings, as that will also sand down the CA glue on the bushings and make it thinner and easier to remove.

The advantage to non-stick bushings, even with odorless CA glue

I’ve been using non-stick bushings even with the odorless glue (I put some paste wax on them to help it come off, though I don’t know for sure how much it’s helping because I don’t want to risk trying it and not being able to get the glue off my bushings) because they have a key advantage:

Non-stick bushings are narrower than even slimline barrels, so there is a gap between their end and the end of your barrel.

I’ve found this has made it a lot easier to separate my bushings from my barrels before sanding and without cracking the CA on my barrels.

Here’s a pair of pictures illustrating the difference between how non-stick bushings have a bit of a gap between the barrel and the bushing, versus the slimline bushings which rest right against the barrel (there’s a few coats of CA on the barrels in the bottom picture, which is why they don’t look perfectly smooth.)

Cleaning the CA off your bushings

I have a separate article on that: Cleaning CA Glue Off Your Bushings

Sanding the end of the barrel

You will likely have a bit of CA sticking off the edge of the barrel from the bushings. It’s very critical that you sand this off, or you will likely crack the CA off your barrel when you press the pen together.

Just put some sandpaper of any low-ish grit flat on the table and sand each end of each barrel in a circle until the CA is flush with the brass barrel. (You can also do this process now, or earlier, to make sure the polymer is flush with the brass barrel.)

Don’t sand the end of the barrel on a surface with any give to it (like a towel), as that will cause the sandpaper to curl up over the edges of the barrel and sand those further down as well.

I use ~120-180 grit but honestly, anything low works. I just happen to have a lot of that grit.

Sanding the CA

By applying the CA, you added some height to your pen, and you will want to get it back down to closer to the bushing height.

  • If you used non-stick bushings, remove them and put your regular bushings back on.
  • If you used regular bushings, pull the CA off them.

I prefer to use abranet and micromesh for sanding CA, but you can use any sanding or polishing materials.

Note that all the sanding below is wet sanding.

First, you want to sand each barrel thoroughly: I use 600-800 grit abranet mesh for this. “Thoroughly” means you see almost no shiny spots (which are places where the CA is lower, and therefore not sanded yet.) The fewer shiny spots, the smoother and glossier your final surface will be. This is the most critical step.

If you are feeling the need to go down to 120 or 220 grit sandpaper, You probably have too many bumps in your CA and need to adjust your technique.

Next, go through your levels of micromesh or sandpaper at 800+ and then finishing paper. Just like when you sanded the pen barrel, always sand length-wise after each grit (read my article on sanding pen barrels for more information; much applies to the CA sanding as well.)

Don’t sand too much — or maybe do

Remember it is completely possible to actually sand all the CA off your barrel — which may be exactly what you want to do if you messed up.

You can always start over with CA again, even if there’s a bit of CA left on an over-sanded barrel. It’ll work just like applying a second coat of CA did before.

If you find a flat spot, or a spot with too little CA, you can always add more.

Polishing

Novus plastic clean and shine (#1) gives a beautiful finish after all the sanding is done. It’s inexpensive and worth using.

Just squirt some on something like a low or lint-free paper towel or cotton cloth or whatever, and rub it back and forth while your pen barrels spin for 10-20 seconds.

Don’t apply so much that it flies off the barrel and decorates your clay room — you can always add more if you want to do more polishing.

Buffing?

While you certainly can buff, like you’re used to with other polymer clay projects, it has two disadvantages:

  • Pen blanks aren’t the easiest to hold while buffing and can more easily slip out of your hands (though buffing them on the mandrel helps, you will need to use your fingers to stop them from spinning too much), but more importantly
  • Buffing creates heat, and heat that high can cause CA glue to get cloudy

Given the low price of products like Novus, and long shelf life, my recommendation would be a plastic polish instead, despite it being a bit messier and another product to buy.

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