Denatured Alcohol & Acrylic Blanks

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Is it safe to use denatured alcohol to clean up an acrylic blank after sanding and prior to polishing the blank? I always seem to get black dust residue on all of my blanks during sanding. Any tips to avoid that or how to deal with it?
 
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leehljp

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There are different methods for dealing with this.

The best method is to not get the sanding dust onto the blank, and that is by what is known as TBC - Turning Between Centers. (No Mandrel)
Most people (but not all) who use TBC - turn close to size with the bushings on, then take the bushings off and put the blank back on - between the live center and drive/dead center, and finish turning to size or sanding to size. This requires a greatly advocated and more precise way of determining the size - using a good set of calipers to measure the size. Measure the fittings - nib/cone end, write the size down, Measure the cap end and write it down; if two piece pen, measure the center band and do the same. Turn to size. NO SANDING DUST!

With experience, and for anyone who will take the time to practice using their turning tool, AND practice sharpening their tool of choice, a blank can usually be turned as smooth as if 1000 grit sand paper were used.

(By the way, Those new to turning need to know that turning to the bushings SIZE should be ditched as soon as possible. Once a tool touches the bushing as it is turning fast, the size will be reduced by about .003 or so. Sanding will do the same. After 20 pens it will have reduced the size at the blank by at least 1/16 inch. Long ago, new turners were taught that bushings are "consumables", i.e. throw-aways if using for measuring to size.)

The bushings are on in this view (and no mandrel is used.) But not using a mandrel, taking the blank off, then taking the bushings off and putting the blank back on without the bushings - is a matter of about 10 seconds. And without the bushings, there is not sanding dust.
 
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penicillin

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Feb 27, 2019
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I had similar problems. The root cause was the sandpaper touching the metal bushings and bringing fine metal particles onto (and into) the pen blank.

Before sanding, I change out the metal bushings and replace them with the cone shaped plastic ones. You can buy "non-stick" plastic bushings from many sources, and some people make their own. Here is the one I use:
https://www.rockler.com/non-stick-pen-bushings-for-ca-finish

You must be very careful to limit the sanding to the surface. Do not allow the sandpaper to round over or shrink the ends, especially considering how hard you worked to match the bushings (or caliper measurement).
 

jttheclockman

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Feb 22, 2005
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A few things here. Because you asked a few questions, yes you can use DNA on acrylics without worries. Second is you should not get black marks on acrylics that do not easily rub off. DNA will do that. Next is as others mentioned 2 things can be done when it comes to sanding blanks and getting contamination weather from bushings or from woods bleeding into one another or metal accents making black marks due to sanding, the first is to throw away the sandpaper and use your tools to get you to proper size. A good sharp tool will get you there as Hank suggested. The second thing would be to switch out to those cone shaped bushings and sand between centers and thus you eliminate the sanding dust from the bushings but from contamination of woods and also metal accents no this will not work. Then the sharp tool thing is needed.

One thing I want to make note of is what Hank said to new turners, (By the way, Those new to turning need to know that turning to the bushings SIZE should be ditched as soon as possible. Once a tool touches the bushing as it is turning fast, the size will be reduced by about .003 or so. Sanding will do the same. After 20 pens it will have reduced the size at the blank by at least 1/16 inch. Long ago, new turners were taught that bushings are "consumables", i.e. throw-aways if using for measuring to size.)
Yes it is true that bushings get worn from tools hitting them or sandpaper hitting them but in my eyes they are not so much a consumable made out to be. I purposely turn my bushings down even when brand new and it does not bother me one bit they are now smaller than the kit. Why you ask, it is because bushings are just a guide. They are not the true dimension of the kit. This is the point that should be made to all new turners.
Learn to use a good set of calipers to tun your pens to. Measure the components and then turn the blank accordingly. I use bushing mainly to get me in the ballpark and to hold my blank. I have been using the same mandrel and bushing sets from the first time I bought them. No need to throw away good equipment.
 

leehljp

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Yes it is true that bushings get worn from tools hitting them or sandpaper hitting them but in my eyes they are not so much a consumable made out to be. I purposely turn my bushings down even when brand new and it does not bother me one bit they are now smaller than the kit. Why you ask, it is because bushings are just a guide. They are not the true dimension of the kit. This is the point that should be made to all new turners.
Learn to use a good set of calipers to tun your pens to. Measure the components and then turn the blank accordingly. I use bushing mainly to get me in the ballpark and to hold my blank. I have been using the same mandrel and bushing sets from the first time I bought them. No need to throw away good equipment.
John was much more correct than I was. I was heading you in the right direction, but John is hitting the nail on the head.

IF one always uses bushings for sizing, then it is a consumable as it loses its purpose with time and use. And as John said, they are not as precise as comparing to the pen's diameters. IF one uses the bushings as a guide and to get started, you can use them forever (if they are precise enough in their fitting into the tube, and in their concentricy.)
 

egnald

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Jun 9, 2017
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Columbus, Nebraska, USA
I always wet sand on my plastic blanks and I rarely start with a coarser grit than 400. Typically I use 400 using another blank as a backer to make sure everything stays flat and that I even out any high spots. Then I go to 600 and 800 before switching to MicroMesh. If you wet sand and wipe the slurry off with paper towel between grits you shouldn't have any dust to deal with. As someone has already mentioned, be extra cautious when you get close to the bushings and don't over sand.

Dave

PS I also stopped using wet plastic polishes and invested in a stand alone buffer. It seemed like I always had a microscopic pinhole or two in my blanks that would fill in with the polish and I would wind up with tiny white dots. I use blue rouge on a sewn cotton wheel first and a final polish with a loosely sewn flannel wheel. (Depending on the finish after MicroMesh I can often even skip the buffing).
 

Mailbag

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Sep 18, 2021
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Location
Ohio
I had similar problems. The root cause was the sandpaper touching the metal bushings and bringing fine metal particles onto (and into) the pen blank.

Before sanding, I change out the metal bushings and replace them with the cone shaped plastic ones. You can buy "non-stick" plastic bushings from many sources, and some people make their own. Here is the one I use:
https://www.rockler.com/non-stick-pen-bushings-for-ca-finish

You must be very careful to limit the sanding to the surface. Do not allow the sandpaper to round over or shrink the ends, especially considering how hard you worked to match the bushings (or caliper measurement).
Thanks so much for the info. I just started working for the Cincinnati, Ohio Rockler Store this past Monday. I’ll certainly be looking to purchase those non-stick bushings.
 
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