the IAP forums are also a good source of finishing information
http://www.penturners.org/.
There are as many ways to apply a CA finish as there are people that apply it. Ultimately figure out what works for you.
General rules:
Be aware of the species you are working with some take CA finishes better than others.
Make sure you are using fresh CA It really does matter for the finish.
Use different viscosities of CA start with Thin CA (5 cps) 1-2 coats so the pores get closed up. Then move to Medium CA (100 cps).
Sanding of the wood before finishing is important but anything past 320/400 only effects the chatoyance (How the wood absorbs and reflects light) of the wood. some woods have greater potential for chatoyance than others and often times burnishing the wood after sanding to 220 gives better results than sanding.
Use a skew or other shear cutting tool for your final pass when creating the profile, this cuts down on sanding.
When sanding on the lathe under power, use a light touch too much pressure on the wood can cause out of round conditions and generates excessive heat. Stop the lathe and sand with the grain and clean off previous grits between grits.
Never use steel wool or rags on a spinning surface. The potential for personal injury is just way too high. Use paper towels instead. If they get caught, they just tear away before grabbing a finger.
It is important to understand that CA does not layer like shellacs and lacquers do. CA bonds between applications and creates 1 single layer. The number of applications to apply depends on how thick you want the CA surface to be.
The secret to a glossy shine on any finish is scratch removal!
My finishing process:
Make fianl pass cutting with a very sharp 1/2" skew.
Change bushings to plastic finishing bushing (delrin or polyturethane) I made my own these are a series of 4 cones with approximate 60 degree angles. The CA does not stick to the pastic like it will to the metal bushings. The bushings look like this when installed ->---<>---<-
Start sanding at 320 (possibly back down to 220 if needed) sand util smooth and any tooling marks are gone. Stop the lathe and sand with the grain make sure any scratches around the circumference are removed. Wipe down with a clean cloth and repeat the process through higher grits. I usually stop at 600 but sometimes I'll stop at 400 It all depends on how it looks. Sometimes I will burnish the wood to bring up the chatoyance. test by weeting the wood either with mineral spirits or water. Remember if you use water it will raise the grain and you will have to sand again. There have been times where I have skipped sanding altogether because I was happy with the reults from the skew and no major flaws were present, the chatoyance was what I wanted, so move on.
For applyng the CA I use bounty paper towels folded into quarters to create an applicator that is 4 plys thick. I put 2-3 drop of Thin CA and apply. With the running around 1000-1500 or so I put 2-3 drops on the applicator and very rapidly move the applicator side to side along the axis of the pen tube to apply. Sometimes i do a second application of thin, this depends on the porosity of the wood. Next is 4-5 applications of medium CA using the same process for the the thin. I do use a shot of CA accelerator between applications of Medium CA (because I'm in a hurry). Again the exact number of aplications depends If I have to build the pen boidy back up to meet the dimension of the hardware then now is the time to do it. Apply until the CA is approximately .001" - .005" above the measurement of the hardware.
I have found my best results wet sanding the CA layer from 220 to 600. Starting with 220 sand until the entire finish is uniform and no shiny bits are showing this levels the surface. And gets the pen to it's final diameter. With the lathe off sand with the grain of the wood and wipe down to remove any sanding dust.
Measure the diameters where hardware will meet the pen it should be no more than .001" +- of the hardware dimension. If it is too large, then sand some more, if too small apply more CA and remeasure.
Sand 320, 400, 600 in succession. (sometimes I stop at 400 if I'm happy with the appearance) remember to sand with the grain and clean between grits.
I then take the pen off of the mandrel take the mandrel off of the lathe and install buffing wheels. I use tripoli on a stitched cotton wheel for better cutting action and scratch removal, then white diamond, and then a plastic polish compound on loose flannel wheels. Buff with the grain along the axis of the pen. I made a buffing mandrel to hold the pen tubes making buffing easier. I then finish off with McGuires liquid gold carnuba wax. If it's good enough for show cars it should be good enough for a pen.
My thoughts and observations:
Many people micromesh to 12000 and then buff, some use MM only, ultimately the glossy finish comes with scratch removal. Some people get out magnifiers to check for scratches. I just go with what looks god to the eye and feels right in the hand.
I have not gone the expense of micromesh yet. I prefer to spend my money on materials and tooling rather than consumables. Buffing wheels are inexpensive and last a really long time if maintained properly. Buffing compounds are also inexpensive and last a long time also. From what I hear MM pads are good for about 60-80 or so pens. I make about 100 pens a year (I like pens) and have only used about 10 percent of my buffing compound, I figure I have about 10 more years before I need to buy again.
Finishing is a very personal process, and no two people do it the same. My own finishing process is constantly evolving as I try new things. Like now moving away from CA. CA has 3 main advantages over other finishes for pens.
1. It's fast By far this is the fastest finish to apply. With practice I can now finish a turned pen in about 8-10 minutes.
2. It's very durable, probably the toughest most acid resistant finish available for pens.
3. It can provide a super glossy glass like finish.
I am thinking about looking into some of the other oil based finishes used by pipe makers. These too are pretty tough relatively fast (slower than CA but from what I understand faster than dipping in poly) and can also provide a high gloss but without the plasticy feel of a CA finish.
Explore and experiment to find what work best for you.
