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Pouring Resin: Easy and Inexpensive

Mixing the resin

The mixing process involves two parts 1. – Resin and 2. – Catalyst. The Resin is the base plastic. The catalyst is a ‘change agent’; it chemically interacts with the resin producing heat. The end result of the interaction is the hardening of the resin.

Mixing the resin can require a bit of experimentation. The back of the resin container does provide some guidance. The guide gives you an idea of how much catalyst to add to a given amount (ounces) of resin based on how thick the pouring will be. In the example for this article the subject was small compared to the amount of resin mixed. The mixing was done with ˝ ounce of resin. The cast only required a very small fraction of that, just around 20 drops from a toothpick. It is important to base your resin/catalyst ratio based on the mixing amount, not the amount actually poured in the mold.

Mixing can be done in any container. It’s recommended to use a disposable one because cleaning a non-disposable container is quite time consuming and difficult. Disposable containers abound, the top part of a kids yogurt cup, condiment containers from the local fast food place, or you can purchase inexpensive ones from a DIY or hobby store.

Place the empty container on a food scale and ‘zero out’ the weight. Pour in a measurable amount of resin, in this case ˝ oz. Read the back of the resin can and determine how much catalyst to add. Base the quantity on the weight and size of the mixing container. In this example 18 drops were used. Stir the two completely together. You can see small ‘ripples’ where the catalyst and resin mix. Make sure you have a very even mix.

Pouring the resin

Pouring is straightforward. There are two factors to consider the size of the mold and the size of the mixing container. Pouring should be done with care to reduce the amount of bubbles allowed in the resin. Tipping the mold so the resin slowly runs down the side to the bottom (kinda like pouring a good draft beer) helps reduce bubbles. Another method is to use a toothpick or stirrer stick and place it over the opening of the mixing container in a diameter fashion. Then slowly pour the resin so it runs down the toothpick into the mold.

The resin used in this example shrinks just a bit when it dries. Allow for this by adding a bit extra at this point. Note: It only shrank at the opening. The rest of the cast was exactly the size of the mold. In this example there is a large variance between the mixing container and the mold and a toothpick was used. Resin was collected on a toothpick and allowed to slowly drip off into the mold.

Project Photos
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About the Author

About Scott Lodder (slodder)
FROM: NORTH CAROLINA, UNITED STATES

I modeled when I was a teenager. College, family and work stopped me for a while. Then I picked it back up after about 12 years off. My main focus is dioramas. I like the complete artistic method of story telling. Dioramas involve so many aspects of modeling and I enjoy getting involved in the ...


Comments

This is very helpful. Thanks Slodder for writing it.
MAR 15, 2003 - 11:28 AM
Thanks for hundred times!!! This is what I need to build my own conversion set from resin. Michal
MAR 15, 2003 - 07:21 PM
VERY NICE THANKS ROBERTO
MAR 16, 2003 - 08:15 AM
very good artcile.thanks slodder
MAR 16, 2003 - 06:25 PM
Solid article... and some real nice pictures. On small flat pieces, I also use a lot of Latex rubber mold, but I apply it with a cheap "sponge" paintbrush. that I discard after use. I also use the re-inforcement fiberglass tape every third layer, and do a minimum of 6 total layers. Here are a couple of other tips I would add, based on my experience of trial and error: 1) to reduce bubbles, place the mold on a sheet of cardboard, and set it on top of your cloths drier. Throw a few wet towels in the dryer. After pouring the resin, turn on the dryer and the tumbling vibrations of the wet towels in the dryer willl shake loose 99% of any trapped bubbles... this also works well if casting plaster in the mold. 2) If you are casting in a cold room (below 60-degrees F), you might consider putting the filled mold into your microwave. once it is poured and still in liquid form.. any additional heat that you can provide to the cold resin will aid in curing to a harder finish... but BE CAREFUL, especially on small items... if you over-heat, your resin may actually MELT back to liquid, and start "boiling".... stay nearby, and start with small timed increments of 15-20 seconds. I find this technique works extremely well, especially on molds with really fine, thin detail. 3) Take your time and measure accurately... if you use too little catalyst, then the finished piece will come out of the mold sticky and oily. If you think this may have been a bad "pour - hit the microwave - and the sooner the better! 4) When pouring resin, consider using wax paper or disposable cardboard beneath the mold - resin pouring often results in some drips and strands of "spider webs"....and the stuff when wet doesn't come off of a wooden or formica tabletop easily. If you DO spill some resin on a cherished surface - DON'T (D-O-N-'T) try to wipe it up while it is wet... it will only smear into a superfine coat. Just let it "set up". Once it is firm and hard, you may be able to "pop" or slide the piece off.
MAR 16, 2003 - 06:49 PM
Never had much luck with this resin to thick for me. But great article!! (++) (:-)
DEC 07, 2003 - 11:29 AM
Good article, Scott. Have you considered trying silicone to make your molds ? It's a bit more expensive, but a lot easier (and less smelly and messy) to work with. Happy to help you out if you like more information on this subject... Jan
DEC 07, 2003 - 11:51 AM
Hey, GF, I think Santa is going to be kind to me in the silicone area. So I'll be 'picking your brain' come January. The idea of the latex mold was to keep it simple and cheap for small items. It's come in very handy a few times. Waiting for January.........................
DEC 07, 2003 - 01:15 PM