Wednesday, April 13, 2011

The Myth of Mold Release

Mold release is the nemesis of the resin hobby project.  With the ability to make an expensive and beautiful model utterly unpaintable, it is to be feared and respected.  However, can an over-abundance of mold release be misdiagnosed?

My Chinnork/Ravager conversions had been moving along smoothly, as you can see from the picture above.  Ciaran, from The Overlords, was kind enough to send me the exact dimensions of  a Dark Eldar Ravager, and I have built my conversions with those specifications in mind.  As with all of my conversion work, I have added a bit of size to the model, in an effort to show my opponents that I am in fact modelling for dis-advantage.  I really enjoy creating unique collections of miniatures, and the possibility of someone calling my conversions unfair is something that I go great lengths to avoid.  Here is another shot, including a Rhino to give you a sense of scale: 

While I know that it is not easy to see detail on the conversion work that I have done, I think I like the ambiguity.  Once the army is painted, I will post detailed close-ups.  Regardless, I was in the process of building my second Chinnork/Ravager when disaster struck.

Naturally, I had washed and scrubbed all of the resin parts to these kits before attempting to build the models.  The second Chinnork kit I was working on, even after a thorough washing and scrubbing, seemed... off.  The model had MANY bits of the original pale-blue rubber mold stuck in the cracks and crevices, and the resin itself just felt greasy.  No matter how I tried to wash the mold release off, the model was still a bit slick.  Due to the somewhat caustic nature of P3 primer, I hoped I could just "prime through" this issue.  Taking a stick of this greasy resin sprue out to my garage for a primer test, I found that the mold release was not to be so easily defeated.  The P3 primer scraped right off.  Zap-a-gap wouldn't stick to the greasy resin, either.  Something was amiss.

I scoured the internet in search of solutions.  I read about people spraying a layer of varnish onto their kits in order to give the primer something to stick to, but that sounded like a good way to lose detail.  I read one story about a guy accidentally dissolving part of his titan (eek!) in some chemical cleaner.  I even read a forum where someone said that grain alcohol was a great solvent for removing mold release.  Not wanting to accidentally waste my expensive resin model, or my cheap grain alcohol for that matter, I decided to go to the source.

This morning, I called Forge World directly, and told them my problem.  Interestingly enough, they told me that this was not a mold-release issue, but a resin issue.  They said that sometimes the resin itself does not "set" correctly, and so it took on a greasy finish to it.  They assured me that no amount of scrubbing or chemical dips would remove this, as it would be like trying to wash the meat off of a meatball.  They have since mailed me a replacement kit, hopefully of a less slippery resin.

What have I learned here?  First of all, not all slippery resin models can be fixed with washing or dipping.  Secondly, that Forge World customer service is top-notch.  While I would love to high-five myself here and think I somehow scored a free $100 kit out of the situation, I honestly cannot do anything with the greasy Chinnork parts that are now on my desk.  I also hope that this anecdote does not motivate anyone to try and scam Forge World by claiming their order is unusable...  I would think they can keep a record of these things, and can identify by order number when a batch of "bad resin" may have gone out.

In other news, my Dais of Destruction is coming along quite well.  While I had visualized all of the components and the final product, seeing the bits coming together has been extraordinarily exciting.  I think it really captures the aesthetic I have been going for with this project.  Once I have something worth showing, I will post it up.  Over the last few weeks, I was struggling with feeling disconnected from these Skaven / Dark Eldar models I have been building.  I suppose reading codexes and websites that never have pictures or stories about such a unique army, left me feeling a bit isolated from the more "official" 40k universe.  However, seeing the Dais take shape, with my Ravagers and Reavers in formation on a nearby shelf, is beginning to get me pretty excited. 


  1. It's certainly worth keeping hold of the parts if you can, i've had resin in a similar state to yours dry out over a period of time. Took a while, but the resin will cure properly eventually.

  2. Dan, congrats on the progress. A far as the greasy model, yeah that does happen sometimes. I have worked with resin a considerable amount, and usually that happens when the resin isn't mixed fully or if there is considerably more of one of the two parts in the mix, which sometimes happens when you are nearing the end of a container.

    Keep up the good work.

  3. Big Steve: Hmmm... I wonder if this kit will also dry out, and just how long it will take.

    HuronBH: I am happy the project is on track to be finished by NOVA. Maybe I can get a Howling Griffon rematch? As for resin, I don't know much about the casting process, so I appreciate the insight.

  4. I had this problem with a few spots of a Forgeworld Thunderbolt I built recently. Luckily, it was a large model with large flat surfaces, so I took some modelling sand paper and roughed the surface up. This worked fine on this piece and I didn't worry much as this will not be a regular gaming model.

  5. That copter model looks really good man, I can't wait to see it painted.

  6. Basically it happens when either the mixture of the resin (as it's an A+B type thing) is out of whack, or one (or even both) parts of the mixture have "turned" chemically.

    It won't always cure over time, but as Big Steve suggests, it could end up setting properly - it could be a few weeks, it could be 6+ months. You just never know with this sort of thing, and it could conceivably take years to fully set (much like Greek cement).

    It's a good thing their customer service is that good, considering the ungodly prices they charge. I just hope I haven't run into the same thing with my Bloodthirster that just arrived - it's pretty greasy, but I haven't tried to clean it quite yet. Thankfully the "cheap" stuff in there came out fine.

  7. Looking good Dan. I cant wait to see it fully done.

  8. Thanks guys!

    I guess I will leave the greasy resin on a shelf. Maybe one day it will be usable...

  9. Most resin cures threw a thermal reaction in the chemical change of state. So it can conceivably be 'forced' to cure by putting steady heat on it (like 100-140 degrees) for several hours. Most resins can handle at least 190 degrees or more (I use one that can handle up to 400 degrees). So if you want to try, you can always set your oven to 100-140 (newer ovens make this simple... us with old ones just have to guesstimate) and put the bits on a tray in the middle of the oven for an hour. Remember to keep an eye on it while doing so though.

    It may work to help cure it. But I can't guarantee anything.

  10. Heard good things about their customer service when people call them, less than good things about people who email them. Either way by now I know that calling them is the way to go:)

    Cool conversion :)

  11. Dan, I am always up for a rematch. Though the HG will not be returning the Open this year. I be playing a new army. That said no reason I can't bring both and give you a crack at the Griffons again Friday or during after hours open play.

  12. Nice, Jay. My friend and I will be arriving on Friday, so perhaps an open game is in order. As a warm-up to the weekend. =P

  13. Very interesting. I have several FW kits that are like this, but I have not tried priming them yet. Should I have issues I will swear off FW forever as they will have cost me hundreds of dollars in now wasted, unusable models. >:(