Polishing Epoxy with Polishing Compound and Drill

A work of art, table or anything else you made out of epoxy resin, may get scratched over time. Epoxy resin scratches quite easilly, this is not a bad thing, as epoxy is a material that can be polished very well. For this, however, you need to use the right epoxy polishing paste and follow the right steps, such as sanding the epoxy. In this article, we explain step by step how best to polish and sand epoxy. In addition, we tell you exactly what you need.

How come epoxy scratches so easily?

Not all epoxy systems have the same mechanical strength. It is therefore possible that scratches may occur on the epoxy. For higher scratch resistance, it can be finished with DD Paint. This is a harder 2-component PU paint that improves scratch resistance.

It is also possible that the mixing ratio was not maintained properly, resulting in the epoxy not being fully cured. As a result, it achieves a lower hardness (shore D). A post-cure can be used to try to develop a few more per cent of mechanical strength.

Before polishing, it is important to let the epoxy cure for 5 to 7 days first!

Equipment needed to polish epoxy

• RESION High Gloss Polish (polishing paste)
• Support disc for drilling machine (77 mm) (small surfaces)
• Mirka Deros (large surfaces)
• Applicator pad 77 mm
• Polishing pads 77 mm
• Polishing cloth
• Spray nebuliser for water
• Sanding discs 150 mm per 5
  
  • in the following grit sizes: 
    • 240
    • 320
    • 400
    • 600
    • 800
    • 1000
    • 1200
• Mirka Abralon 125 mm abrasive discs
  
  • in the following grit sizes:
    
    • 1000
    • 2000
    • 3000

Step 1. Cleaning

Make sure the surface you want to polish is thoroughly clean. We always do this with acetone because it cleans very well. Once the surface has been cleaned, you can easily see what needs to be polished and decide what grain size to use to sand the epoxy. Note: sanding too finely will not get rid of deeper scratches.

Step 2. Sand your epoxy with coarse grit discs

You can start with epoxy sanding. Start with the coarsest grit and take your time with this. It's better to sand a little longer than too short and hasty. For epoxy sanding, use a good sander with an adjustable speed such as the Mirka Deros or the Rupes LS71T Delta. These sanders are an investment, but especially if you work with them more often, it's one of the better investments you can make! Is it about a small area? Then do it with a drill and Support disc for drilling machine (75 mm). Don't step up to a finer grit too quickly. Clean the surface regularly between epoxy sanding with a clean cloth and a little acetone.

Step 3. Sand your epoxy with fine grit discs

Once you get to 1000-grit, it's time to switch to abrasive discs. These are of better quality and give better results when fine sanding epoxy. From grit 1000 onwards, we recommend working with the pencil method. This way you can be sure you are sanding in the right way. Again, regularly clean the epoxy surface with a little acetone so you can judge the surface properly. Do you still see a large scratch somewhere? Then go back to a coarser grit and build it up again from there.

Step 4. Coarse polishing with sheepskin

After sanding the epoxy comes the first 'polishing' step. Do this with the sheepskin and RESION High Gloss Polish. For smaller surfaces, we have an attachment for drills and a 77 mm sheepskin. So for smaller workpieces, there is no need to work with a large polisher. For larger workpieces, as with sanding, we recommend a polishing machine with adjustable RPM like the Riwax polisher 150 mm. This makes it much easier to polish a large surface.

Apply some epoxy polishing compound to the pad and start polishing at a low speed. Spray water on the surface occasionally so that the epoxy does not get too hot. This will prevent damage.

Step 5. Assess the surface

After polishing with the sheepskin, you can assess the surface. Should you still see bad spots and scratches now, you will have to sand again and build up towards polishing. Are you satisfied? Then you can start polishing for a fine shine with a harder polishing pad. Again, we recommend using a machine if it is a large surface. Cool the surface regularly with water to prevent damage to the epoxy.

Final tips

RESION High Gloss Polish is a polishing paste specially formulated for epoxy. This polishing paste performs excellently on epoxy substrates. To polish DD Paint, we recommend using Riwax RS02, RS04 and RS08.

More information

Want more information on epoxy sanding or polishing? Then feel free to contact us. Our experts are at your service. Of course, you can find more information in our knowledge centre.