Sizing your CA finish

**Tiger** · 21st May 2014, 12:42 PM

I've been thinking about this since talking to Dai Sensei. Is there any method that you use to ensure that when you put the finish on, you end up with a diameter that matches the pen kit, instead of being slightly larger? So to explain a bit further, you trim your pen blanks a fraction smaller than the bushings, build up with CA and then sand/polish the CA so that it's all flush with the pen parts. Calipers are a big help here but do you shoot for eg 0.1mm of CA or is it more a guesstimate of how much you need? You need to be fairly precise with matching the pen parts as you can generally feel even a couple of thousandths out so you've got to be pretty close with your sizing.

**dai sensei** · 21st May 2014, 01:08 PM

For simple timber I use min 0.2mm, for WW or cast items 0.5-1.0mm depending on finish required

**Tiger** · 21st May 2014, 01:55 PM

Thanks Neil, so for a slimline where the nib is 8.5 mm you'd turn that down to approx 8.3 mm and then build it up to a little over 8.5 and sand it down to 8.5 mm?

**dai sensei** · 21st May 2014, 02:58 PM

Yep, although I'd turn to 8.5, then sand to 8.3

**Tiger** · 22nd May 2014, 02:16 PM

Ok, so I tried a slimline last night and got the digital calipers out, I found it to be quite a painstaking task to get the ends of the barrels to match the pen parts. Normally this isn't a big problem with other finishes because you just turn to the bushing size but with CA, if you go too far with the sanding you need to apply more coats etc. To get a better fit I've heard of people radiusing the pen barrel edges, does this work ok with CA finishes ie does it take some of the CA off (and ruin the finish) and if you use this method, what grit do you use to radius? I'd imagine pretty fine and a pretty small angle of chamfering/radiusing.