Black Alumilite Blank - Can’t get ride of the scratches!

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Pitchman

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Aug 24, 2019
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Johns Creek GA
Help! A desperate pen turner! LOL

I have been turning for a number of years now and just recently decided to make my own blanks as I wanted them tube in. I have turned to Alumilite first as that seems to be a common preference? Here’s my problem…anyone have a real solution? I simply cannot get the black blanks to a point where they do not have any scratches…or at least extremely minimal.

I have used all 9 micro mesh, counter sanded at each stage, used Novus 3, and Novus 2, and a few other tricks and still cant get a smooth scratch free blank.

Suggestions?
 
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duncsuss

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It sounds like you have some deep scratches that are not removed before you move up to the next grit level.

Or your fine Micromesh is old and polluted with coarse material, so you only think you are polishing with 12,000 grit. That's the reason I've stopped using Micromesh and switched to 3M Tri-mite non-woven polishing cloth (sometimes called "Zona papers" - do a search for Zona and you'll find plenty of posts that talk about it.) When I cut it into 1" x 3" strips, it's so cheap that I use it once and throw it straight in the trash.
 

JohnU

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I always put a Gluboost finish over my alumilite blanks after I micromesh them. I start with the red bottle and put a layer because it wicks into the scratches. Thicker finish may just encase the scratches in the finish to be seen. Then I apply 4-5 layers of the orange bottle. I finish with micromesh and buff. It finishes to a glass like surface. The problem with black is everything is visible against it and the scratches in the resin can hold dust making them more visible. As long as they are very small scratches and not abrasive deep ones this should do the trick. It works for me.
 
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I have also found it works best to use gentle pressure when sanding. If you push too hard you put the scratches in as you are sanding them out.
 

jttheclockman

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Feb 22, 2005
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Jim, I believe that no matter what material you start with the key to a good finish is to start with one with very minimal scratches and to me the key is to use a skew to give that final shape. It is a tool that will leave a fine blemish free finish. The MM and as mentioned not hard pressure and I always wet sand to help lubricate the sanding pads. Good luck.
 

jrista

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Like John T. said, it helps a lot to use the tool to get the smoothest finish you can by the time you are done turning. There is usually a particular grit with any set of sandpaper, where its much harder to introduce those deep scratches. For wood I usually use a set of wet/dry sandpapers I get from Woodcraft (I forget the brand), for resins I use either MicroMesh or Zona paper (or both).

I have found that the 320 grit or lower sandpaper will almost always leave deeper scratches that I then have to get rid of. Even with a light touch, sandpaper is a cutting tool, and after that initial few seconds of contact a lot of the grit will be ground down, but you sometimes have random remaining sharp granules that can introduce deeper scratches. I usually try to turn my blanks so that I can start at 400 or even 600 grit. With 400 grit there is still some potential for deeper scratches, but with 600 grit it pretty much never happens. If I can get a really smooth surface just with the tool, I start at 600.

If you find that you have deeper scratches, usually you have to back up the grits to the next one above the grit that causes the scratches, and work them out. Sometimes you may even need to back up to the actual grit that caused the scratches. It helps to check for deeper scratches every grit or two, and see if you need to do this, before continuing through the final grit.

Resins can suffer the same issues. Wet sanding can really help when sanding resins. Some times I'll start with 400 or 600 grit dry sandpaper with a light touch just to smooth out the shape if it is not perfect, then wet sand from there on. I used to use micromesh exclusively with resins, but I recently found Zona paper, which has been giving me a much, much better, shinier finish by the time I get down to the 1 micron grit. I then use a high grit plastic polish (I've used a number, I don't recall exactly which one I've been using lately as the label fell off the bottle, but it does wonders and gives me a very, very shiny, smooth finish.) I have always found that with resins, sandpapers alone (normal wet/dry, micromesh wet, zona paper wet) never quite seem to get me to a true scratch-free point. I've always had to use a polish (or a series of progressive polishes) to reduce the scratch size to "effectively invisible".
 

Sylvanite

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In terms of showing scratches, Alumilite RC3 Black is the most demanding material I have used. I buff my pen blanks and find that although acrylic and polyester blanks (and blanks finished with CA) look good after Tripoli and White Diamond, Alumilite Black still shows tiny scratches. I believe that's because:
  1. RC3 Black (urethane) is softer than the other plastics, and
  2. It's black. Solid black just shows scratches more.
Therefore, when buffing Alumilite Black (and the Clear too), I proceed beyond White Diamond and buff with the finer blue compound and a dry Canton flannel buff. That yields a high-gloss scratch-free finish. It's necessary to keep a light touch when buffing. A heavy hand can actually introduce ripples into the surface.

I hope that helps,
Eric
 

TonyL

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I just sent you a PM. I am not far from you. I can show you how to get them out.
 

TonyL

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I couldn't get them out at Jim's place Siper guy, make beautiful HQ pens), but I just did at my place with the buffing wheels. I just sent him the pics. Black is beautiful, but a bit....of a challenge (keeping it family-friendly).
 
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