# tiny scratches in acrylic



## RollTide (Dec 17, 2007)

I just can't seem to get out those little tiny scratches from an acrylic blank. I sand through 12k mm and finish with a polish. I still have those tiny little scratches though. Anybody wanna share their method? I'm wondering if my problem may be that I have first started with a 500 grit.

Steve


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## Brewmeister35 (Dec 17, 2007)

With each grit, I sand mine with the lathe on, then lengthwise with the lathe off.  Wet sanding with the MM does wonders too.


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## alamocdc (Dec 17, 2007)

Wet sanding took care of mine. I rarely have to start with 320 grit wet/dry, but will if necessary. Then all MM grits wet, then plastic polish.


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## ed4copies (Dec 17, 2007)

If the scratches are visible, they probably came from an early grit (or your final polish RAG (papertowel included).

Stop the lathe from time to time to inspect.  I found in my outdoor demos, the final papertowel was putting the final scratches in, changed brands (actually, I now use kleenex nose-blowers), problem solved.


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## IPD_Mrs (Dec 17, 2007)

Also, Have you tried Novus?  That is what worked for us on both CA finish and as Ed puts it, "plastic".

Mike & Linda


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## ed4copies (Dec 17, 2007)

To clarify, outdoors I use Novus on everything.  The Novus worked great, but my towel left final scratches.  Outdoors I am also using a Jet Mini VS, so its turning around 4000 rpm, scratches seem to get pretty deep at that speed - maybe no connection![8]


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## txbatons (Dec 17, 2007)

I have to second (third...fourth?) wet sanding. I haven't had any problems since I switched to wet sanding and plastic polish. I'm also very careful to cover the lathe bed so I don't get water on it. Rust is bad!


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## avbill (Dec 17, 2007)

This is what I use on plastic or acrylic after 12,000 mm. 

Micro-GlossTM Liquid Abrasive 

Made by the same company that manufactures Micro-Mesh,  Micro-Gloss is formulated to remove, not hide, superficial scratches and light surface damage.  A general purpose water-based liquid that uses a 1 micron abrasive crystal. An excellent compound for use on acrylics!   Comes in an 8oz bottle with dispenser. $8.95.    

Special note:  This compound is meant to be used with a buffing wheel.  We strongly recommend that you have one dedicated buffing wheel for Micro-Gloss.  You do not want any other buffing compound to come in contact with the wheel used for Micro-Gloss.  When not using the dedicated Micro-Gloss buffing wheel store in a plastic zip-lock bag to keep it clean.


you will find this product at http://arizonasilhouette.com/Micro_Mesh.htm

bill daniels


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## maxwell_smart007 (Dec 17, 2007)

I finally figured out how to get rid of the scratches on mine...

After I sand with each grit, I take a lint free buffing cloth, and rub off the residue...then I'm starting each grit on bare 'plastic' without having to worry about grit or residue from the sanding process etching the blank...

Seems to work ok for me, but I haven't done that many yet...but a HUGE improvement over the first ones I did! 

ANdrew


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## MikeyTn (Dec 17, 2007)

I've had this same problem before. How I solved it was by sanding at a higher grit from the start. Before I would wet sand starting with 320 then 400, 600 then move to 1500 micromesh. Then move from there all the way up to 12000 grit. Now I start out with no less than 600 wet and use a light touch and re-wetting often. My lathe is running at second highest speed the entire time. (Sorry but I forget the RPMs.)


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## Blind_Squirrel (Dec 17, 2007)

Switch to the Beall buffing system.  Three steps, about three minutes, glass clear. http://www.bealltool.com/products/buffing/buffer.php


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## RollTide (Dec 17, 2007)

Thanks for all of the replies. I just cleaned up my MM pads and am about to go try the wet sanding. See how that does. Those little scratches are very annoying!


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## ashaw (Dec 17, 2007)

I had the same problem when applying the polish with a paper towel.   The towel put back scratch into the acrylic.  I have for over a year been using micro-fiber pads found in any of the auto supply store.  They work great and cost next to nothing.


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## rherrell (Dec 17, 2007)

> _Originally posted by Blind_Squirrel_
> 
> Switch to the Beall buffing system.  Three steps, about three minutes, glass clear. http://www.bealltool.com/products/buffing/buffer.php



I'll second that!


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## RollTide (Dec 18, 2007)

I guess I'm gonna have to check into the Beall system. I also want their collet chuck system!


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## leehljp (Dec 18, 2007)

What everyone said above. One more thing:

Fluorescent bulbs and especially with diffused lighting will cause "scratches" to appear - that are not actually there.  IF this is the case, then It is only refracted light from a thousand points of diffusion. 

I could get a perfect finish on a pen, look at it outside in the sun and it would be outstanding; then in the living room/den under fluorescent bulbs with diffusers - it would look awful on close inspection.


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## 2rcbruce (Dec 19, 2007)

I used to get similar scratches on cocobolo. I solved the problem by stopping the lathe and then sanding length wise. I always sand from 120 to 600 then mm 1500 to 12000, always sanding length after each grit.


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## CHICAGOHAND (Dec 19, 2007)

I have been using the micro mesh that I bought from woodcraft, while squirting water mixed with dish soap,(an old trick I learned wet sanding cars). Near the end of each grit i wipe the blank off with a cotton cloth. The last few steps I sand and or wipe lengthwise.
 I have been using some plastic automotive polishers with great success applied with these polishing bonnets held in my hand very cautiously. I have thought about cutting them up into small pieces but I probably wont do that until it gets ripped out of my hand and sends my heart throught he roof.
These squirt bottles were bought at harbour freight for a few bucks.
I just turned a black with red lines  acrylic blank and this thing has to be the best finish I have achieved yet.I just cant seem to get a good pic because of the reflection.Here is a pic of one before the black and red.







I use this platform and baking tin to catch most of the water that I squirt on the blanks.


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## RussFairfield (Dec 19, 2007)

I haevn't read any of the replies, but I will add my nickles worth of advice anyway; and offer my apology if I am being repetitious. 

Your scratches are most likely left over from the 1st grit you started sanding with, and you just weren't able to see them until you approached the polished surface of the 12,000 Micro Mesh.

There is merit in the advice to remove ALL of the scratch pattern from the previous grit before moving to the next finer grit. This is difficult to do at the coarser grits because you won't be able to see the difference; but it becomes more obvious that you haven't done this as you get into the finer grits.

Sanding both directions always helps because it make sanding easier with the next finer grit, but it also breaks up the scratch pattern into a finer arrangement of lines.

Wet sanding at the finer grits also helps on acrylic because the lubricant keeps the sandpaper from cutting as deep into the plastic, hence a finer scratch pattern than you would get from dry sanding. I use a few drops of kerosene for this, but water works fine on plastics

Sometimes these scratches are there because we used cheap sandpaper that had a larger grit particle on the surface, and it only takes one big particle to leave a permanent scratch.  One of the merits of starting our sanding with the coarser grits of Micri Mesh is that the grit particles are a more uniform size that any other sanding medium. This is why it costs more money than common sandpaper. You can rake the sandpaper over a sharp edge of a piece of steel to break the really big ones off the surface.

Now that you already have the scratches, you can either spend a lot of time trying to remove them with the finest grits and polishes, or you can go back a few grits, make sure thay are all removed, and then proceed up through the grits again. When I find these scratches, I usually do back to 320 grit, and wet sand until they are removed because that is the fastest for me.


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## YoYoSpin (Dec 19, 2007)

Wet sand...220, 400 and 600 grits followed by tripoli abrasive buff and then white diamond polish buff, and you're done (IMHO)[8D]


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## Blind_Squirrel (Dec 19, 2007)

> _Originally posted by YoYoSpin_
> 
> Wet sand...220, 400 and 600 grits followed by tripoli abrasive buff and then white diamond polish buff, and you're done (IMHO)[8D]



Ed, I only do 320 Abranet dry (hand sanding lengthwise) before taking it to the Beall.  They come out glass clear (just like you showed us on your 3D resin bottle stopper video )


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## mtbrooks (Dec 21, 2007)

I'm sure the ways that others have described work well but why go to all that trouble?  

With the pen blanks turning at 1200-1500 rpm:

1. Sand major tool marks out using Norton's 220 grit
2. Sand Nortn's 400 grit
3. Micro Mesh (dry) 1500 - 12000
4. EEE Ultra Shine Polish-This stuff is the bomb!

Done! Glass like everytime as long as you don't press the 220 or 400 grit paper too hard while using them.


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## RosezPenZ (Dec 23, 2007)

Thanks Hank,  I have been having the same problem.  It did not dawn on me it maybe the lights,  I use a fluorescent bulb in a magnifier to look for scratches,sometimes its enough to make me quit.

ok, no one hit me too hard but why Beall system, shouldn't any set up using the proper wheels and compunds work, or is there really that much difference between wheels and buffing compunds?

I dont mean to "steal" anyting from you steve, I'm just getting upset also at this problem.


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## RosezPenZ (Dec 23, 2007)

I dont know how to edit my prior post so I post again.  I kept reading and found the answers about the differnce between wheels.  

sorry guys.
[V]
oops, found the edit key,  I think I had better quit for the night.[B)]


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