Different ways of polishing (clear) resin

Hi guys,

I was wondering if it would be nice to have a few (or a lot) of posts describing your way of polishing the clear resin to get that glass effect. I know clear lacquer is a great way to get a glass looking finish easily, but some of you go through all sorts of sanding stages to get the same result. Or in most cases, a better result.

Perhaps this could be a central topic where we can learn from each others “wins” (and mistakes), and do’s and don’ts, when it comes to polishing the resin. Perhaps even starting with the curing process.

I know there’s a how-to in the support page of Formlabs, but in most cases the community creates better methods based on those how-to’s.

Right now every method of cleaning and sanding the clear resin is scattered throughout the forum and are often hard to find. Hopefully in this topic we can gather all the information that benefits us all.

Once a few different explanations have been posted I’ll change the topic name so new members will be able to find this topic with ease.

I’m looking forward to your detailed explanations! I myself am experimenting with different solvents to see the effect but haven’t had much success without the clear lacquer as of yet!

I know @Gantelet_Stephane, @Thomas_Judy, @Steve_Johnstone and @ericwang have had beautiful results with sanding and polishing their parts. Perhaps it would be nice to share their methods step-by-step?


Note: The aim for this topic is not to have several replies with “I use copper polish” or “I use a dremel”, but more a step-by-step guide on how you went from a rough part to a shiny polished glass-like result. :slight_smile:

I have found the dremel goes too quickly to polish and just tarnishes the clear resin.

As to polishing to glass,

  • Start with 240 grit wet and dry paper to remove the nubbins left from the supports using water throughout. For large flat surfaces, putting the paper on the desk and moving the model over the top in a small pool of water works best to keep the surface flat.
  • Resand in 3 or 4 stages finishing off with a 1500grit wet and dry paper using water throughout
  • At this point clear off the model with water to remove residue
  • Spraying with WD40 at this point and wiping will give a slightly matt finish. The UV spray will give a nice shiny gloss finish.

I bought a rechargeable electric toothbrush, pulled all the bristles out of the snap on end. Then added a small piece of firm foam pad, type used to backup rubber stamps. Attached the pad with 15 minute epoxy. I then took a piece of 220 grit sandpaper, plastic back type, and double stick taped that to the pad. With interchangeable ends I can have many shapes to the pad and sandpaper. This does easy work of sanding the prints and only cost $20 at Target.

  • Walt

Hi Alex. I tried to make my replie like you ask with photos of m’y step by
step. Feel Free to take the pictures and rewrite my comment elswhere in a
more clear manner is You wish as english is not my birth language and is
quite aproximate. Good idea anyway.

I printed and polished a lens last year and my process is (somewhat) documented in this blog post: http://formlabs.com/company/blog/2014/09/24/lenses-3D-printed-formlabs/


Hi @Alex_Vermeer, this is a great Idea.

When I get a chance I will try and better document how finish my clear parts.

The only problem is that I keep changing things and at the moment wire wool is the flavor of the month. :stuck_out_tongue_winking_eye:

One thing that I have found respectably effective is painting with clear resin after the print has been finished in the baths of alcohol as prescribed by Formlabs. Using the clear resin that Formlabs makes as an aftercoat works quite well in my tests for non-high-impact products. After printing I treat as usual and then delicately coat the unit in a very thin layer of Formlabs clear resin. Afterwards, I delicately place it outside underneath an Icee cup lid ( to protect the wet surface from particles while allowing intense direct light from above ) surrounded by mirrors in order to magnify the lights intensity. I let it sit for appx three hours and If the sun is out this process has yielded a surprisingly clear printed unit. I have to emphasis the delicacy in this process though because too much resin will cause the coat to form undesired surface differences and an improperly prepared outdoor curing position will allow particles to randomly interact with the unit. I live in Texas, so my general sunshine potential is quite high most days which expedites the process some. Indirect sunlight takes longer but is definitely more controllable when it comes to precise tempering. Essentially it just needs direct sunlight and a thin layer of resin applied to the top. I have also attempted to sunlight cure without alcohol curing and it yields the same results but can leave those smaller string residues on the surface if they arent removed. A thicker layer of resin produces a visual somewhat resembling Spanish imperfection glass, but with resin build ups toward the bottom of the unit.
Hope this helped someone and I will be doing further tests of resin painting to see if I can obtain consistent accuracy. Happy engineering everyone

Yes, George. I did the some thing, putting a layer of clear resin on top. It saves polish time. Just need to beware the dust sticking on top.

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.