Basic Resin Art Techniques

Welcome back to the beautiful world of resin art.  Last time we laid out a lot of information on how to set up your workspace and what materials are available for you to use in the creation of resin artworks.  In this blog post we will introduce you to some basic resin art techniques, including how to mix, color & apply resin and how to use resin art templates.  We will limit ourselves to talking exclusively about epoxy resin and will save UV resin for a future post.

Understanding your resin: Always follow the manufacturer's instructions with respect to safety precautions when handling resin.   Even if the resin says that it is VOC free or low odor always work, as a minimum, in a well-ventilated area and always wear disposable gloves.

Your resin bottles will normally be marked with an A and a B (or Part A and Part B) to indicate that their contents are different.  One will contain “resin” and the other will contain “hardener”.  Mixing the two parts together causes them to react with each other transforming the 2 liquids into a single solid.  Normally this reaction is gradual, with the mixture remaining fairly fluid for around 30 minutes, viscous but fluid for around 6 hours, tacky for a further 2 hours, touch cured after 12 hours and fully cured after 72 hours.  Resin brand, temperature and depth of pour can affect these timings though, so you will need to experiment a little. 

The resin bottles will state the mixing ratio for that brand of resin.    Most tabletop epoxy resin is 1:1 ratio by volume, meaning that for every unit volume of part A you use, you also need to use the same volume of part B.  So, for example, if you want 3 oz of resin that is 1:1 ratio by volume you will need 1 ½ fluid oz of part A and 1 ½ fluid oz of part B.

Deep pour resin / casting resin may have a ratio of 2:1 by volume meaning that you would need 2 units volume of resin (part A) for every unit volume of hardener (Part B).   So if you wanted to mix 3 oz of resin that is 2:1 ratio by volume you will need 2 fluid oz of part A and 1 fluid oz part B.  Note - Deep pour resins tend to require at least double the curing time of tabletop epoxies, although the working time can also be longer.

There are of course brands that require other mixing ratios and have different curing times and it is important that you do what it says on the product labelling.  To make your life simpler though, I recommend you buy resin with 1:1 mixing ratio and about 30 minutes of working time.

Mixing Epoxy Resin: Prepare only the resin you can use within about 20 minutes.  You can mix more when you run out, but having too much resin that is quickly curing adds unwanted time pressure to your process.  Multiple small batches works best. Mixing small volumes also helps prevent thermal run away, where the curing resin starts to get hot, causing the resin to cure faster and release more heat, causing it to get even hotter and cure even faster.  It is really important to mix the correct ratio of resin and hardener and to mix it very thoroughly or it will fail to fully cure, so measure accurately.

This is the step-by-step process that I use to mix my 1:1 ratio resin.

1. Take 2 disposable 3oz paper cups
2. Mark a line with a pencil on the inside of one of the cups. With experience you will soon be able to eyeball just the right amount, but for now let’s put a mark about 1/3 the height of the cup.
   
   
3. Fill the cup to the line with hardener. Hardener tends to be less viscous and so flows better than the resin. 
   
   
4. Empty this cup into the second cup and scrape out all of the hardener as best you can.
   
   
5. Fill the first cup to the line again, this time with resin.
   
   
6. Transfer this to the second cup as before.
7. Stir the mixture for at least 30 seconds with a stirring stick.
   
   
8. Pick up the cup and continue to stir it this time focusing on scraping the side walls and bottom. I like to rotate the cup during this step as it helps ensure all the sides are scraped.  Do this for at least another 30 seconds.
9. Important – unmixed resin or hardener will never cure and can destroy your piece by making a sticky mess. If you are not sure that you have stirred every little corner of the cup, keep stirring until you are sure.
10. Check the mix for streaks and clarity.  Well mixed resin should have no visible streaks.
    
    

You should now have about 2 oz of perfectly mixed resin ready to use.

Again, I recommend you mix your resin in small batches like this, however if you need to know how much resin you will need in total for your artwork you can reference the following table.

Coloring your resin:

Before coloring you need to estimate how much of each color you need and decant that amount of resin into separate cups.  Then to color with different media do the following:

Resin Dyes – For all transparent, translucent and opaque resin dyes add the color a few drops at a time by squeezing the bottle over your cup of resin.  Mix well, ensuring that there are no unmixed corners by taking time to scrape the sides and bottom of the cup.  Check your mixture to see if the color density is what you were looking for, and if not add some more dye and repeat the process.  Note that even though it may look intensely colored in the cup, when poured in a thin layer it may look washed out.  So always check by adding a drop to a test area or by looking at a thin layer on your stirring stick.  Colors can be mixed to give new colors, but you won't always get the result you want, so try a sample before committing to blending a whole cup.  For example with the brand I use, red and blue make a muddy black color and not the rich purple that I would like.

Mica Powders / Pigment Powders – A little of these goes a long way so add a small amount at a time using the end of a stirring stick.  Stir it in gently to start, as the powder can fly into the air in a cloud otherwise and maybe land on your artwork.  Repeat the process if more color density is required.  Thin layers of micas can let light pass through (not normally in a good way) so depending on your application and substrate you may want to increase the amount of mica you use.   Micas can be mixed to give blended colors and this can give some fantastic and surprising results.  Pigment powders are variable in their mixability and the colors tend to be really intense meaning that darker hues will dominate any attempt to mix them.

Pigment Pastes – These pastes are highly concentrated and so you only need a tiny amount to turn your transparent resin into an opaque flat colored liquid.  Use a stirring stick to scoop some from the tub and stir it directly into your resin.  I rarely find that I need to go back for more, but you can if you need to.  As with all colorants it’s best to test a small area before committing to pouring it onto your artwork.

Acrylic Paints – You want to keep the amount of paint you add to the resin as small as possible as it will react and can turn gummy if you add too much.  Therefore, I recommend you mix the color you want first using only the paint and then add this finished color to the resin just before you pour it.  Most acrylic paints are quite heavily pigment loaded and so you don’t need a lot to make an opaque color.  As always mix them thoroughly making sure there is no unmixed resin in the corners of your cup.

Glitters – Glitter has an instant effect on the viscosity of the resin.  When mixed in it becomes a suspension of particles in a clear liquid and while this gives a unique and beautifully deep effect, it does mean you need to add quite a lot – maybe up to 25% of the volume of the resin.  This adds a lot of bulk and makes the resin mix flow more slowly.    You can still add the glitter using a stirring stick, but it may be easier to use a spoon or to pour it from the pouch or tub.  Then stir it, slowly to start as it may fly everywhere, folding it in until it is all wetted prior to thoroughly mixing it through.  Cure times are not significantly affected by glitter.

Using Templates:

Resin Art templates are a great way to bring a little bit of structure to your artwork.  Although resin moves slowly it doesn’t stop moving until it cures, meaning that you can spend a long time making a beautiful piece of art, only to find it has changed into an amorphous blur by the morning.  This is even more noticeable when you mix different media types in your piece.  Resin colored with micas and glitters tends to float over dyed resin and so where the 2 meet there is no stopping them mixing with each other.  Using a resin art template provides barriers for the resin to keep it where you put it and to prevent different media from mixing.  Pour Away Fluid Arts provides over a hundred different designs of template, from abstract patterns to detailed animal representations and most things in between.  They are intended to stay in place as a part of the finished piece without being overly intrusive.  The idea is derived from the cloisonne method of making jewelry and other decorative items, and for that reason we only use copper colored PLA to reflect the copper wires used in cloisonne.   You can of course use actual wires to achieve the same end result.

Sticking your template in place:

There are 2 methods to sticking your template in place on your substrate.  In both cases your aim should be to completely seal the template to the panel using as little resin as possible.  When I say seal the template to the panel I mean that it should be stuck down with no little gaps underneath where resin could escape when you come to add color.  We want to use as little resin as possible so that the cells are not partially filled with resin and that there is sufficient room left to add your color.

Method 1: The coat and position method

This method is the most obvious way to stick a template to a substrate. 

1. Take your panel or canvas and fully coat the top surface with a thin layer of resin. Remember less resin is better – you just want enough to cover the surface and no more.  If you have mixed too much, its better not use all of it rather than compromise the space you’ll have for colored resin later on.
   
   
2. Position your template into the layer of resin and give it a bit of a wiggle to make sure its fully coated on the bottom surface. The wiggle is important if you have a very thin layer of resin.
   
   
3. Then check everything for alignment and that there are no gaps between the template and the substrate.
4. Cure overnight.

Method 2: The dip and place method.

Method 2a: This method is perfect for times when you are prepping two or more templates at the same time, but can also be used if you are only prepping 1.  It is also the only method that works when using release film.

1. If prepping two or more templates then you should coat your first panel as for method 1 above. 
   
   
2. Place your template into the resin on this panel and give it a wiggle to ensure the bottom surface is fully coated. 
   
   
3. Prepare a second panel or sheet of release film, but leave it dry.
4. Carefully pick the template up and place it onto your second panel or sheet of release film. Try to position it accurately as possible first try as there will only be enough resin to allow small adjustments. 
   
   
5. Check alignment and that there are no gaps between the template and the substrate.
6. Use the first panel for another template per method 1.
7. Cure overnight.

Method 2b: If prepping 1 template, most often used if you are prepping a stand alone template using release film.

1. Prepare a panel, or sheet of release film, ready to receive the template
2. Mix a small amount of resin and pour it onto a scrap of plastic sheet. I use a piece of disposable table covering or a canvas/panel with the protective film still in place.
3. Spread the resin out as far as possible
4. Dip the template into the resin bit by bit until it is fully coated. You may need to blot off any excess resin if you have picked up a lot.
   
   
    
   
5. Place the template onto your panel or release film. Try to position it accurately as possible first try, as there will only be enough resin to allow small adjustments. 
   
   
6. Check alignment and that there are no gaps between the template and the substrate.
7. Cure overnight.

Pouring Resin:

Resin will flow further than you imagine especially if there is a slope on your substrate, including templates.  Take some time to ensure your workpiece is level before pouring.  You can do this using a small spirit level or an ap on your phone.  I use spare stirring sticks placed under the substrate to level it.

Using disposable paper cups to mix your resin has the added benefit that you can also use the cup to pour from.  If you make a small crease in the rim of the cup you should be able to form a v shaped spout as shown below, simply by squeezing either side of the crease.  With practice you should be able to squeeze the spout and close it, preventing any resin from escaping.  Then relaxing your grip slightly you should have full control over the amount of resin that is poured – from a tiny drip to a fairly rapid pour. 

Because of the surface tension that resin has it is not possible to drip any less than a minimum drip size.  This “smallest drip” can be used to fill small regions of a template for example and you will soon be able to judge how many drips a region needs.  There will be some regions that are smaller than the smallest drip and for these I recommend you place the resin using a dotting tool or a stirring stick.  Dip the tool into the resin to pick some up and then touch the template to break the surface tension and allow a smaller amount to transfer to the smallest regions.

In all cases of resin application it is best to underfill the cell (area defined by the walls of the template) and let gravity level the resin out.  Try to not keep pouring resin until the cell looks full as it will very likely to be overfilled and to spill into an adjacent cell.  Continue to fill other cells while the first ones filled self level.  Once the resin has spread and levelled itself you can go back and top them up to fill the template to flush with the top.

For large areas (or if you are impatient like me) you may need to help the resin flow into all corners of the cell.  For some narrow cells it can be possible to overflow one end of the area before enough resin has been added to allow self leveling to cover the bottom surface.  This can be especially true if the resin is more viscous due to coloring or partial curing.  In all cases use a stirring stick or a dotting tool to help move the resin into the dry areas of the cell as shown below.  Then leave to self level as normal.

Removing Air Bubbles:

Once mixed, resin has a tendency to de-gas in the form of releasing bubbles.  When resin is freshly mixed these will give the resin a cloudy look, but after a while the small bubbles will combine into bigger bubbles and start to rise to the surface.  There are various ways to reduce bubbles during the mixing process and prior to pouring, but that is for another day.  For now you can leave the resin in the cup for 5 or 10 minutes to allow the bubbles to rise to the surface.  Use a heat gun or propane torch to gently heat the surface of the resin and pop any air bubbles that may have formed.  Be really careful not to over heat as resin will burn.  Hold the heat source a few inches above the surface and move it in a circular motion until the bubbles disappear.  Always keep the heat source moving.  You can also pop the bubbles with a small mist of 95% + Isopropyl alcohol if you prefer to avoid heat.

Once poured more bubbles will emerge and these should be popped in the same way.  It’s a good idea to return to your piece after 20 minutes and then again after another 20 minutes to pop bubbles and generally just check up on things and fix anything that has gone wrong.

Hints and tips:

1. Mix multiple batches of small quantities of resin so that you have time to use it all before it starts to cure.
2. Larger volumes of resin are more likely to experience thermal runaway as they have a lower surface area to volume ratio
3. Thin layers of resin can take a long time to fully cure as they don’t get warm during curing.  You may need to leave thin pieces for a week or more.
4. Always try to underfill the cells of a template – you can top them up later if needed, but trying to fully fill at the start may cause overfilling and spilling into adjacent cells.

Join us next time where we will go step by step through an example project from start to finish. 

I’m Jonny Nelson, ex engineer and now full-time resin artist and creative director for Pour Away Fluid Arts.