CRAFTING WITH RESIN: WINS & FAILS

WELCOME TO AMATEUR HOUR! LEARN FROM MY F’UPS AND SUCCESSES OF WORKING WITH SILICONE RUBBER LIQUID BOX POUR MOLD AND DEEP POUR RESIN. Bubbles in silicone rubber molds and clear resin are a problem… or can be. There are soooooo many tips available online. I tried all of them outside of buying a pressure pot or vacuum chamber because I am frugal. My commitment to perfection battles with my love of convenience. All the below do’s and dont’s are cost effective. Some of them might seem silly and you might think to yourself “why would anyone do that!?!?!” Well desperation to get rid of bubbles led me to some pretty desperate measures. After lots of trials, I finally feel that my end resin deep pour product is POPPIN’!

YOU’LL NEED:

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PLASTER CASTS & BOX POUR MOLD

WIN! Sealer Spray or Acrylic Gloss Finish Spray works well to smooth out defects in Plaster of Paris castings and prevents the material from releasing air bubbles into the silicone rubber liquid mold.

WIN! Reuse plastic food containers (like salsa) for silicone rubber liquid box pour mold containers.

WIN! Platinum based silicone rubber mold liquid has a longer shelf life than tin based materials and is less likely to have a bad reaction to craft store resins.

WIN! Pressing the handle end of a electric sander against the mold does help bring air bubbles up to the surface. I have also read that a coffee grinder works well also.

WIN! Leaving the freshly poured mold in the refrigerator for an hour to slow the curing process so that bubbles can have time to surface does help ensure that the end result will be perfection.

WIN! Earthquake putty is great for bonding your casting form (in my case a Plaster of Paris jello mold) to your mold container. It is awesome for creating a barrier around an area where you need to re-pour a little resin for small repairs. Air got trapped around the top edge of my mold creating air bubbles in my resin. This was easily remedied by adding a little putty around the gap and patching the hole with resin. Other air bubble gaps are hardly noticeable after gently sanding them away.

FAIL! Do not use a mold that has micro champagne size bubbles even it the mold feels smooth to the touch. The first silicone rubber mold I poured was riddled with tiny bubbles that did not feel as if they would affect the surface, but did in fact create little air pockets that caused air bubbles in the resin form. The technique of pouring the silicone rubber mix 30” above the mold in a long, thin stream to one location helped prevent bubbles in the new molds.

FAIL! Do not pour resin directly into tin jello mold unless you to do mind totally destroying the tin. Even mold release spray did not help in the removal process. However I will say the end result was a had a nice satin finish, few bubbles and cured evenly. The metal tin has less viscosity than the silicone rubber mold so there was less chance of air getting trapped on the mold surface.

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POURING THE RESIN

WIN! I mark the pour amount on the measuring cups with a black permanent marker for each project. This allows the translucent marks to be seen after the cup has been filled with resin and for the cups to be reusable.

WIN! A little mold release seems to help with the resin form removal and to smooth any mold surface texture that might create air opportunities for air bubbles.

WIN! Use a space heater to even out your workspace temperature to the low 70 degrees and to gently warm silicone rubber molds and resin/hardener bottles. Temperature differences can create bubbles.

WIN! If the bottles are still chilly, submerging them in warm water can help bring them up to room temp. Make sure the bottles are completely dried and free of water.

WIN! Shallow plastic salsa container is great for mixing and torching resin. The wider surface area allows for more bubbles to make it to the surface for easy removal.

WIN! Mix the components really slowly so to not introduce more air into the liquid. If your resin has a longer working time (like 45 mins.) let for a couple mins. to allow the bubbles to rise to the surface for easy torching.

WIN! Pour the resin into the mold as close to the surface as possible so to not introduce more air into the mix.

WIN! Pour a small amount of resin and swirl it around the mold to coat the surface to break up any potential trapped air pockets. Flexing and squeezing the mold also helps get the resin in all the pockets.

I get intense when it comes to bubbles and have added a really, really bright flashlight to my arsenal of tools. It helps illuminate any bubbles that might have been otherwise overlooked.

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WIN! I read that mica powder changes the surface viscosity and in so doing creates less opportunities for bubbles to appear. I am not sure that this totally worked for me, but it sure does make the resin awful purdy!

WIN! About 1.5 hours (depending on your product’s curing time) after pouring the resin into the mold, a cutting of wire (about 20 gauge) can be used to gently move any rogue bubbles to the surface for removal. A swift sweep of a lighter flame will quickly pop any bubbles in the middle of the mold. Keep the flame away from the mold walls. I found that bubbles will continue to appear, but at least there are less.

SUPER SLOW curing resin will allow enough time for bubbles to rise to the surface or for you to manually remove them before the product has gone too far into the curing process.
The product I used in the below images has a tack-free time of 24-72 hours and will cure fully in 5-7 days.

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FAIL! Do not torch into your silicone rubber mold or you risk damaging it. As it turns out the mold is in fact flammable. Oops! Do not torch within 6 inches of your resin or too long in one spot or you might burn your resin. I lost a bit of resin due to burning it to a yellowed, congealed substance. Gross! A sweeping motion helps avoid any damage and waste.

FAIL! Some online sources recommend using a heat gun to remove bubbles only with oven safe silicone rubber mold material, but I did not find it useful and you could risk damaging the mold. This process will definitely cause waves in the resin surface.

FAIL! Do not heat the resin mix in hot water. This will bring all bubbles to the surface quickly, but you lose working time. I found that submerging the mix in super hot water did help bring all the bubbles to the surface for easy removal but did not prevent more bubbles from being created once the resin was poured into the mold. The bubbles were even larger than the champagne size bubbles I was previously tackling. This was due to temperature differences of the resin mix and the mold. Heating the mold to balance out the temperature change did not help prevent these bubbles from occurring. This in fact exasperated the bubble issues, making them even larger.

FAIL! Avoid using wood tools, like tongue depressors or popsicle sticks, to mix the resin as the organic materials can introduce air into your resin. I use a plastic spoon handle and mix the components really, really slowly.

FAIL! Vibrating the mold does not seem to release bubbles as the silicone seems shock absorbent.

Do not try to remove bubbles with a dry toothpick or wire once the resin has congealed and started to solidify.
DAB THE AREA WITH A LITTLE ACETONE TO SEE IF YOU CAN GET THE BUBBLES TO RISE. I was able to remove some troublesome bubbles with a piece of wire dipped in acetone (really strong nail polish remover).

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OPTIONAL: CLAY FRUIT CONFETTI & GLOSS FINISH

WIN! Polymer clay sinks. So if you want to add clay fruit to your design and have it float, wait around 2 hours (if you have a slower curing resin) before adding your items. Add them vertically opposed to horizontally to avoid trapping any air bubbles. I found that an Exacto blade is a great tool to use to submerge the fruit into the resin at different depths and rotating them under the surface. Wait to around 15 mins. to add a second round of clay fruit. This ensures that you will have fruit distributed evenly throughout your form.

WIN! Paper and air clay items will float to the surface no matter what stage of curing you add them to your resin. I added tiny cuttings of 20 gauge wire to the “marshmallows” so they would sink a little bit into the resin.

WIN! Acrylic clear gloss finish/sealer spray is an awesome product to use to take a resin satin finish to a high gloss sheen. It makes your end product clearer and look higher end.

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FAIL! Do not add any clay fruit or other items too early in the curing process unless you want them to sink and gather at the bottom of your form. I found that ALL the fruit sank to the bottom of the mold opposed to having an even distribution throughout the design.

FAIL! Inclusions made of air or paper clay that do not have a weight component added to it will float.

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CHECK OUT MY RES-ZEN VIDEO

I hope that this information resonated with you and helps on your resin journey 🙂