What an interesting and helpful post! Two questions: 1) when you're buffing a resin pen, what level and method of sanding do you do before blue rouge buffing? 2) Do you use the large wheel buffers (as opposed to the smaller, two wheel set marketed as being for resin pens?
1. I am a huge fan of Zona Paper. Its not exactly a paper...maybe more like something resembling rather dense cheesecloth, covered in a sanding grit. I switched to it from Micro Mesh when I tried it back in 2021, and it has been my go-to for final sanding ever since. This stuff goes down to 1 micron at the highest grit, which is what I always sand to.
To contrast 1 micron with normal sandpaper grits, you are looking at about 14,000 grit in normal sandpapers. This is higher even than the 12,000 of micro mesh, which is about 2 microns. There is something about the nature of the grit and substrate with Zona, that just gives me a better result than any other sandpaper option out there...its more like a fabric than paper, and the grit feels much sharper than what you get with micro mesh (which has a more squarish mesh like crystal structure).
So I sand to basically the finest grit I can. This actually goes very quickly. For CA (GluBoost) and resins, I wet sand from 400-1200 normal grits (Norton sandpaper brand, which also has a fairly sharp crystal.) This takes a couple of minutes or so. I then switch to Zona. I sand from Green (coarsest) to white (finest), or 6 grits in total (green: 30 micron; grey: 15 micron; blue: 8 micron; pink: 3 micron; aqua: 2 micron; white: 1 micron). This takes a couple of minutes. I'll spend some extra time on green and grey, and then also on white, to get the best results. In the end, you should have a very fine shine line. You might notice a slight "glow" around the shine line. This is usually what results from sanding with the lathe on, with radial scratches. You can manually sand lengthwise along the blank with the lathe off to minimize this, however buffing is usually done lengthwise which will have the same result (and then some.)
2. Lately I have been suing 6" buffing wheels for pens. I have 8" buffing wheels as well. I just ended up with 6" when I started this, as that was what was available locally. I don't think it really matters what size wheel when it comes to pens. What matters more is the material. You want to use cotton with the blue rouge, which is a high grit polishing compound for use with almost anything you want to be scratch free in the end. It can be used with CA, resins, most metals (there are a couple of exceptions). Its a general purpose high grit rouge. This stuff just works properly with cotton.
You can get wheels in a few kinds of fabric. Cotton is common, and is good when you need very fine fibers for very fine polishing jobs. Muslin is also cotton. You can find either "treated" (usually a color other than the natural cotton color, such as yellow), which will increase compound retention, but are also usually more aggressive (not ideal for pen buffing).
You can also get flannel buffing wheels. Loose leaf flannel can be useful for final cleaning, and are also commonly used to apply final wax coatings (primarily, carnauba...I do NOT recommend using carnauba, bees, or pretty much any natural wax with shiny pens!! These waxes will DULL the shiny finish, due to the nature of their crystalline structure.) A loose leaf flannel buff can be a good general purpose final cleaning wheel (i.e. don't load it with any compound). I find that for pens, flannel might be a bit too aggressive itself, so I've stuck with muslin or cotton for my cleaning wheels.
There are also some synthetic buffing wheels, notably satin. I've never used these, although I have felt them, and they seem to be a lot more aggressive than either flannel or cotton. Everything I've read indicates they are used for stronger abrasives and rougher work, and are often pre-loaded with a grit or compound.
So, for pens, you can easily pick up a two-wheel buffing kit, load the first wheel with blue rouge, and leave the other unloaded for cleaning, and you'll be on your way.
Oh, I guess I should mention. Not all buffing compounds, even those of the same color, are necessarily equal. I've only bought smaller rouge bars so far. Some have worked really well, some not as well. In that, some really seem to cut through the scratches left by sandpaper really well, whereas others require more effort by you to really clean all the scratches up. Sadly, there really isn't a lot of useful detailed information out there about any given rouge. They are just called by their color, and usually that's it. So its kind of hit or miss, whether you get one that works really great, or not. Maybe its a matter of ratio of grit to substrate, and maybe some have more grit while others have more clay? Honestly cannot say.
There are also other fine polishing compounds out there. Some are unsuitable for resins (notably acrylics), but I did come across purple rouge. Apparently its suitable for acrylic and other resins, metals, and is silica-free. Silica is a common grit compound. Supposedly, purple rouge is capable of providing an even higher shine than blue. I haven't tried any yet (still have a ton of blue from my latest bar). There is also white route, or white diamond. This obviously uses diamond as the grit. Its good for initial buffing, but I haven't found that it really gives a superbly shiny finish in the end. Blue, and maybe purple, are better for getting that sublime shine. That said, if you feel blue (or purple) just isn't quite doing the job to clear out all the scratches from sanding, STARTING with white diamond might be an option, then progress to blue. If you have a three-buff system, you could do white, blue or purple, then bare cotton for final cleanup. I think in the long run, I may be picking up another of Beall's 3-wheel buffing systems (8" wheels), and instead of using the trip/white diamond/carnauba setup, I'm going to do white diamond/purple/bare as my pen buffing system.
Oh, and as a side note. There is also green and red rouge. These are also high grit, high shine polishing compounds...but they are designed for metals. They are not good for resins, ca, acrylic...as they tend to produce more heat, which can be problematic for resins, especially softer ones. In fact, blue rouge is also not suitable for low melting point plastics, but it is fine for most of the resins we use with pens (including acrylic), as is purple.