# Tool marks



## Deadman480 (Oct 12, 2009)

Hey gang , I have a question . I have been doing a lot of back routed plexi glass where i will engrave differant levels and come back and paint them . My question is does anyone know of a good way to get rid of the tooling marks? my biggest problem is when i do a clean out cut the perimiter cut is always a little deeper then the clean out passes so if anyone knows of a good process they could share that would be great . Thanks


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## RJM (Apr 11, 2010)

I've cut plexiglass on the table saw and cutoff saw and I remove the tooling marks by first block sanding starting with 100 grit and finishing with 150 or 220, depending on how flat I want it. I then buff it with red rouge using my buffing wheel. I've also seen an episode of "How It's Made" (or some similar show) that shows how those bank teller partitions are made. They wet sanded then flame polished with an oxy-acetylene torch. I understand there's a learning curve to flame polishing and I haven't tried it yet but the buffing results in a clear surface, just like the as finished surfaces. The amount of waviness in the cut surface will depend on your sanding job - it can be a lot of work.

- I may have misunderstood the question.


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## Phil P (Jul 25, 2010)

For smooth edges on a CNC router I make the first pass 0.1mm "fat" of the required line then do a second pass climb milling (i.e. running in the opposite direction) dead to the required line. This works with many types of plastic as it counteracts the tendency many plastics have to compress and spring back under conventional forward cutting


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## Deadman480 (Oct 12, 2009)

The edges are not my problem its the face of the cut . Basicly I take my design revers the image assign differant depths to differant areas of the image then route out the image so i end up with peaks and valleys on the back side and when you flip it over it looks as if the layers are floating in the plexi . my issue is finishing the valleys . Once you paint it you really can see the tool marks unless you really look but I'm a beliver in there has to be a way to do everything so I was just wondering if there was a finishing tool that would level out the tool makrs .


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## Phil P (Jul 25, 2010)

What sort of cutter are you using and at what feeds/speeds?


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## richmad (Jun 1, 2010)

I'm assuming you not talking about the edges but your routed cuts. 
Try a finish pass using only .001-.002 or even repeat the final cut.
This will be more of a free cut with less tool deflection producing a cleaner cut.
Also a slower feed rate if your machine doesn’t have good rigidity


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