Polishing to perfection

Using the Clear standard resin I wanted to make a see through object.
For the polishing I used a micro motor and the 3M Scotch-Brite Radial Bristle Discs, 80 gritt to 1 micron grit. I’m a big fan of these because there is no need for polishing paste or what soever. I’m really pleased with the result.


Pro tip: next time don’t bath it on IPA and cure it directly. It will end up crystal clear with no polishing steps required :=)


Downside being dimensional accuracy. There can be visible drips with this method.

I think cleaning and then afterwards dipping in heated resin (=more fluid) would yield the most controllable results as you can decide how you dip the part and how it is oriented when you take it out of the resin.


Heated resin, hmmm interesting :wink:

Any “gcode” to heat the resin to be able to perform that? :smiley:

It’s good visibility through the object. How do you think is it possible to make it even more clear?

I suppose I could give it another try with the polishing discs, 3000 grit and 14000 grit (1 micron) and than give it a gloss coat with tamiya XF22 and polish this again for the best possible option. I’m not a big fan of all sorts of polishing compounds those are mostly made for other materials and this materials is i.m.o. softer than e.g. stone or porcelain.

there is a crystal compound used in jewelry and watches to polish plastic just dont overheat it with the friction

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In theory, Clear is perfectly clear, so you should be able to make is as clear as a PMMA or glass casting. FL made a lens for a 3d printed film camera which was much clearer than the photo shown here… although it is admittedly much easier to polish a lens than it is an irregular part.

For the windshield part I did on my last project I had a lot of steps of sandpaper going from 220 up to 20,000, took about 3 hours of sanding to get it good. Also helps to use the Novus 2 + 1 plastic polish. White mineral oil can also help after that.

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thanks, a lens has less thickness to it, that’s far easier to polish.

thanks, that could be very helpful too.

In my experience with clear resin after it has gone through an IPA bath and sanded down, I got amazingly clear results when I sprayed them with Rustoleum Gloss Clear. The pieces are foggy after the bath and sanding, but the spray immediately makes it see through. I love it.


I know I posted about this a while ago but to boil it down to the bare essentials…

Wet sand to a 600 finish (you would start with coarser paper) and finish on a loose muslin wheel charged with ZAM (green polishing compound), this will result in a mirror-like surface rendering the clear, really clear. As another poster noted, do not run your wheel at too high a speed (nor address your wheel with too much pressure), this will basically melt the surface and pull drag marks that will be deeper than you realize and would require more wet sanding to remove prior to re-polishing.

Of course, both sides of your piece (a heart in this example) would need to be polished to have a true transparent, clear result.


I dip clear parts in polyurethane(you can use anything but it makes it chemical resistant as well). Dependent on the speed of the dipping machine, you can get semi clear to high gloss parts.

No post processing like polishing and sanding needed after printing and curing.

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Interesting! I’ve done this with production copper jewelry pieces…I will have to give it a try. Thanks for posting:)

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It depends on the part you’re trying to polish, I was trying out dipping a more complex part but it ended up with a very uneven surface afterwards.

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Novus 3, 2, 1 is how I’d finish it after final sanding with the finest paper you have.

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I polished very complex parts with lots of cavities that have tight tolerances as well to be assembled. Did you do the dipping by hand? Cause that doesn’t work.

You need a dipping machine which is able to vary the pullout speed and you need to find the right viscosity. Slow speeds(ie. 5mm per minute) can make very thin even coatings and there will be zero drops when done.

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Yes that happens with dipping, with these really small rotary wheels you can get in small holes and even do small parts, I really love this, and even more there is less mess and no smell.