Saturday, February 22, 2014

Resin Casting Bases

Ello All!

I recently ventured into resin casting some bases for my new High Elf army and many asked if I would document the process.  So keep reading past the break and we'll dive right into it!

First off, let's talk about safety.  I didn't read up and educate myself before getting started.  As such I exposed myself to the fumes the resin gives off when curing.

This shit is poison.

Wait not that kind of Poison.

Please, Please, Please read the label and all of the warnings BEFORE you start with these products.  Know what you are getting into and how you could be affecting the people in your house.

Work in a well ventilated space
Wear a Respirator at a minimum
Wear rubber gloves at a minimum
After doing some research some of these guys wear full suits when casting.  There are all types of resin though and some are far nastier than the type of stuff you would be using.

One warning I read from a forum that scared the bajesus out of me which I confirmed via some government documentation I found online.
the dangerous compound in polyurethane resin is called isocyanate. it is colorless odorless and extremely hazardous. it can be absorbed by breathing it in and also through contact with the skin.
It will not kill you and the danger is not an acute one. it is a cumulative effect. When it is absorbed it gets into your blood and stays their - it NEVER goes away. continued exposure increases the amount in your system. it has no ill effect until it reaches a critical mass in your system ( different for everyone. When you notice its effects its too late - nothing can be done. The effects usually manifest as symptoms similar to pneumonia I believe. This is known as 'sensitivity' and when it manifests it results in an intolerance to polyurethane plastics. You cannot be in their vicinity without manifesting symptoms to which their is no remedy. There is a lot of polyurethane & polyurethane blends in our lives. Sensitivity makes life extremely difficult. 

You can not be too careful.  You have been warned. 

There is a reason the guys who make and sell resin cast bases charge what they do.  And this is it.  They are handling toxic product.  The process isn't even remotely hard but it is dangerous.  As such, once this project is completed I won't be doing any more resin casting.  It's just not worth the risk and other people live in my gaming space - adversely affecting them in any way would just about kill me.

Sorry all - had to be done.  Now back to our regularly scheduled programming.

Step 1 - Create the originals
I created bases using - MDF bases, cork, stamped sculpey, green stuff, and sand.  I did superglue my sand to the base (I always do).  This may be important though because I noticed on the de-molding that the mold took a few pieces of the vine and sand anyway.  White glue may not be enough to keep your materials on your bases.  Just means more work cleaning out the mold.  I made 10 infantry bases and 6 Cav bases to supply my army.

Step 2 - Prepare the originals for molding

You will want to ensure you are working on a level surface.  I first arranged the bases in a manner that looked appropriate.  You want them close together with smallish gaps in between to reduce mold material waste. Once I was happy with the arrangement I put a little superglue on each of the corners of the underside of the base.  I glued them to a clean piece of Sheet Styrene I got at my local train store.  You can also find this stuff online.  Popular brand names are Plastruct / Evergreen.  Basically any smooth, flat surface would work that you don't care too much about.  (*Probably a bad idea to do this on the dining room table bro!!!)

 I then created a lego frame (don't tell my kid I used his legos plz) to create a retaining wall for the molding material.  I did not superglue the lego frame to the styrene.  Once it was located in the proper position I secured it in place with blue tac and then used the hot glue gun to run a bead of glue around the outside perimeter where it meets the styrene.  I did not want to ruin the legos (and I did not!!).

Step 3 - Make the Mold

The next step is to mix the molding material and pour it in.  This is a two-part molding material.  I used what I had on hand (from a starter kit) which is a product from Smooth-On.  They have a ton of online resources and youtube videos as well.  We used something called OOMO also for casting the minions.  I really like this stuff as you don't need to mess with release agents at any stage of the process.

Mix it up and pour it in.  I did a thin coat and used some small glue applicators I have on hand to push it into all the recesses and then poured the rest.  You want to ensure you are a good bit over your highest point.  I had used the lego to help me figure out how high I had to pour.  I then let it cure a good 12 hours.  (My work surface is not level - something I didn't realize til after the cast). 

Step 4 - De-molding

After letting it cure for 12 hours I came down to de-mold.   I first removed the lego frame.  Then I slowly peeled back 1 corner of the mold.  Ya have to kind of finagle it and it really is only something you can feel but it is really obvious.  Take your time.  Go slow.  Once you have all the originals out I went to work trimming the edges of the mold and cleaning out any sand / vines the mold "swallowed".

Step 5 - Casting

Now with the mold created I set about to create my first bases.  Again using what came in my starter kit I followed the directions on the box and mixed up the 2 part resin material. 

After you mix up the resin, slowly pour it into the mold.  I did my best to try and fill each base to create level bottoms but it was nigh impossible.  It didn't help that my mold was not level since my work surface is not level!  LOL!  After pouring you need something to help you remove any air bubbles from each individual pocket.  The more detail the more little hiding spots for bubbles.  I used these which are quite honestly one of my new favorite hobby tools.

Let the resin cure.  It takes about 10-15 minutes.  Looks pretty cool while it is happening too!

Step 6 - Remove the casts

The next step is simply to remove the cast pieces from the molds.  They often need trimmed and most likely the bottoms will need sanded to get them level.  Please note - sanding / drilling / cutting resin creates resin dust which is as harmful to your health as is inhaling the fumes the resin creates while curing.  Please take adequate precautions!!!  Wear a mask.  I plan to wet-sand my bases underwater to minimize dust.  I will be wearing rubber gloves, long sleeves and a respirator.  

Step 7 - Profit

I was very happy with the level of detail captured.  You can see the sand grains and the HE jewel I added to the base is an exact replica of that part.  

In 3 hours time I was able to cast my mold 8 times creating 80 infantry bases and 8 cav bases!!!

Good luck to you if you choose to head down this path.  Please note all the safety precautions.  It's just not worth doing any harm to yourself.



Mr Saturday said...

Cheers for that, great tutorial.

Herman van Kradenburg said...

Great tutorial. I'd be keen to do this myself if it wasn't for the isocyanates. Cyanoacrylates in glue pose the same risk. I work in the field of Occupational Medicine, and some of the worst cases of asthma I have seen has been due to isocyanates in spraypainters. Accelerators pose the same risk. I have had bronchospasm (closing up of my chest) due to certain brands of cynoacrylate glue and accelerator use. I have become sensitised. Take care if you do this type of casting. Useful info:

Johnny Hastings said...

Great post! Thanks braddah!

D D said...

My daughter has been working with this for a week. No precautions. She was doing what she was shown. She is covered with a rash. Now she read this. She's freaking out. We are calling poison control.

D D said...

My daughter has been working with this for a week. No precautions. She was doing what she was shown. She is covered with a rash. Now she read this. She's freaking out. We are calling poison control.

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