How to Sand and Polish Epoxy Resin to a Mirror Finish - Step by Step Guide

Hey , I'm Carl from glass cast , and today I'm going to be going through the entire process of how to flat and polish epoxy to a mirror like finish .

Flattering and polishing just about anything takes patience , the right tools and a little bit of skill .

But polishing a poxy simply because of how tough it is is particularly hard , and I know how many people struggle with it just by how many customers we speak to in our technical support .

And so in this video , I'm going to be taking you through the whole process .

Step by step , we'll be looking at the tools , the materials and the technique to overcome classic problems like a dull finish or that shiny finish that still shows swirls and scratches .

Whether you're trying to get that perfect finish on a river table , a countertop , a casting or a jewellery piece , the information in this video is for you .

I'll be starting from a rough machine part just like this and begin sanding with 100 and 20 grit , abrasive , then progressively work through the grades right the way up to 1200 before moving on to buffing with a polishing compound and along the way , I'm going to be showing you loads of tips and tricks to help you get over your problems and transform your results .

But before we begin , let's first take a look at the tools and materials that we're going to need .

So in this process we are going to be doing a lot of sanding .

And unless your project is very small , like a jewellery piece , an orbital sander is going to save you a huge amount of time .

Random orbital sander , often referred to as D .

A s , generally come in two different sizes 125 millimetres and 150 millimetres .

In both cases , sanding discs are attached to the machine by this hook and loop interface , meaning that if they are the right size , the most pads fit most machines .

Both of these machines are more than capable of getting you perfect results and are going to be far more effective than hand handing in terms of features .

The ability to connect both these machines to dust extraction is incredibly useful and allows you to sound almost completely dust free .

Throughout the video .

I'm going to be using the Merca sanding discs .

These are the types of discs that you'll find in a lot of professional workshops , and that is for a very good reason .

I'll be using the Abnet disc .

As you can see , these have a mesh construction , which stops them from clogging .

These are also the special ace version of the disc , which is specifically designed for hard materials .

Just like epoxy .

We'll use 121 82 4400 and 800 grit in the Arne before switching to Merca Galaxy for the 1200 grit .

We then have a polishing machine for the compounding stage .

Entry level polishes are fairly inexpensive .

The only features to look out for are variable speed control and a standard 150 millimetre backing plate .

With the polisher , we'll be using a hard and a soft foam pad and these compounds again .

The N W one that we're using here is a special grade of compound that is specifically designed for hard materials , just like epoxy .

I also have a marker pen and a spray bottle filled with water , and I'll explain their use to you shortly as well as the right tools and materials .

The other secret to achieving a perfect mirror like finish on your project is to follow a methodical process , and I do hate to say , but also spending a lot more time on each stage than you would otherwise imagine .

Now I might be tending to skip a step or work faster through the process than I am .

But if you do , you'll just defeat the point of this tutorial .

If you want the results , follow these steps to the letter , right , let's get started .

I've got here an example section of a river table .

But as I said earlier , the principles are exactly the same every time you need to flat and polish epoxy .

The only thing that might change is how course you need to start in this case here , with course machine marks left by the router , we need to start right down at 1 20 .

But if you're just flatting out light scratches in an epoxy counter , then you might want to start at 800 .

To get these lines out , I'm gonna do at least five passes with the 1 20 grip .

For obvious reasons , I'm going to speed the footage up for each step .

But to give you an idea of timescales on this sample piece , which is about a quarter of a square metre , each step is going to take around 10 minutes , sanding from right to left , overlapping the previous line .

We will systematically sand the whole piece , then will send perpendicular to this direction to ensure that the whole area is evenly sanded .

We're going to call this right to left top to bottom action , a single pass .

And , as I say , to ensure that we remove all of the lines left by the router , we're going to do at least five passes .

As you can see , all of the lines have been completely removed and the surface is perfectly flat .

So we're going to repeat this method of right to left up to down several times for each grip , with the addition that in between each pass , we'll mist and wipe away any dust , then draw on the epoxy with the marker pen .

This will help to identify when each pass is removed enough material , and it will help to keep the whole process methodical , so onto the 1 80 grip to make sure we get rid of all the scratches from the 1 20 grip , we're going to do at least five passes with 1 80 .

You can see that I'm not only sanding the epoxy , but also the wood sections , too .

It's important that you do sand over the whole area on a project like this .

Otherwise you'll end up sanding a dip into the resin section .

On the flip side of that , also be mindful that the wood will sound faster than the epoxy so you could move a little faster over the wood sections or apply a little less pressure on the wood .

If you find that on any pass , you are not removing the pen lines .

It means that you're not removing enough material .

This could be because you're either moving the sanda too fast over the epoxy , or that you need to apply a little more downward pressure on the saner .

For the 2 40 again , we'll do five passes , which should be more than enough to remove all the scratches from the previous grit .

Although the abrine discs are incredible and not clogging , they can still occasionally clog .

If you see swirly pigtails like this , stop sanding immediately .

Clean the pad by folding and rolling between your fingers .

If you were to proceed sanding with a clogged disc , you could undo all the work that you've done with many of the previous grits .

However , if your disc is excessively clogged , it would be worth replacing it with a fresh one .

Also , on a point of how many discs you will need for this sample piece , I've used one disc from each grit .

But if you're working on a larger river table , for example , you can expect to use multiple discs from each grit moving on now to 400 grip .

And for this step , we are going to be doing seven passes .

The reason that we're doing seven passes instead of five here is that we're technically missing out the 320 grip .

However , in my experience , it isn't always necessary to include the 320 grip .

An additional few passes with the 400 should achieve the same results , saving you time and having to buy more sanding pads than is necessary before moving on to the next step .

Now is a really good time to inspect the surface between the course of 244 100 grit .

It should be easier to identify if you've removed the deeper scratches from the previous grits .

If you can still see large , swirly scratches in the surface , you may need to go back and repeat a step .

As I can't see any .

I'm going to move forward onto the 100 grit again while we are making a big step from 400 to 800 .

And while it's perfectly fine to double up on the grits , we'll do seven passes to make sure all the scratches from the 400 are removed .

Although we are doing seven passes , it is still taking me about 10 minutes to complete this step on this piece .

Now onto our finest grip .

We're going to switch to the 1200 Merca galaxy to help prevent clogging .

We're going to wet sand so lightly mixed with water in between each pass .

Four passes should be more than enough to remove the scratches from the previous grid .

Also , you'll notice that I'm not marking the resin for this step .

That's because the ink in the water could make an unintentionally stain the wood at this point .

Before we do proceed polishing .

If your project is a mix of both resin and wood , it's best to seal your wood to prevent it from being stained by the polishing compound .

On my sample piece , I'll apply a couple of coats of Danish oil .

So to recap , at this point , we've taken our epoxy surface from a machine finish right the way up to 1200 with the Sandra and abrasives .

And if you've got the right polishing Compound 1200 is as far as you need to go with the saner .

As I mentioned , we're gonna be using two polishing compounds the N W one and a top finish two .

The N W one is specifically designed for hard plastics , just like epoxy , and is quite capable of going from a 1200 grit to a good level of glass .

The top finish two is optional , but it will take that glass to a mirror finish , so we're gonna begin with the N .

W one .

And for this Corr compound , we're gonna use the medium hard pad , begin by applying a small amount of the compound onto the surface and then spread this around with the pad For this step .

We're going to be doing free passes .

I'd like to start off with the polisher on a slower setting while applying a bit of pressure to work the compound into the epoxy .

N W one is self diminishing , meaning that the more it's worked , the finer the grip gets .

One thing to keep in mind is to avoid overheating in the resin .

If you keep the polisher moving , you should be fine .

Being warm to the touch is OK , but if it does feel hot , then you should stop .

Allow the epoxy and the pad to fully cool down before you proceed .

Once the compound has fully diminished , I'll apply a little more and steadily increase the speed while being a little lighter with the pressure as the N W one is self diminishing .

Every time that we add more compound , we effectively start again from its most core state .

So to correctly use it , we need to make sure that for each pass , we completely work the compound to diminish it down until it's so fine it's pretty much disappeared .

We'll wipe away any leftover residue from the N .

W one before we proceed on to that final finish for the top finish .

Two .

We'll now switch to the soft pad .

Same as before .

We'll apply a few blobs and spread this around with the pad starting at a lower speed with light pressure will again work the top .

Finish two into the epoxy , then increasing the speed to both .

After the compound has completely disappeared , we'll add a little bit more and repeat .

Finally , we'll wipe off any residue , buff it with a microfiber and reveal our perfectly polished epoxy .

So there we go .

We have successfully flattered and polished this epoxy .

All of the hard work and attention to detail has really paid off , and we've been left with this glass like surface free of any ripples , swirls and scratches .

As I mentioned earlier , having the right products and materials really does make all the difference .

And so , if you need any of the abrasives , compounds or other products that are used in this guide , they're available to buy from the glass cast resin website .

If you have any questions or feedback , please leave a comment below .

I do always try and answer every question that we get .

And of course , if you have enjoyed this video , please subscribe and you'll get lots and lots of resin tutorials as we release them .

Thank you very much for watching , and I will see you next time .