Tauster's Casting Show

[tauster]

TL;DR:
This thread is to collect all my casting stuff in one place.

One of my favourite techniques is casting. When I started mold making, I found it can be surprisingly easy. This has become one of my most important arrows in the quiver/blades in the xacto knife/insertyourfavouritemetaphorhere. While I have shared most molding experiments somerwhere here, I have posted them in different threads, depending on what was cast. I have inserted most of it (I think...) in my Index thread, but I suspect that some postings slipped through, making the list there incomplete and fragmentary.

[tauster]

I'll repeat the 'Casting for dummies' post from my Index to save me the time & effort of re-linking everything here again. I'll probably update the Index anyway when sharing future casting projects, but experience shows that the Index updates are more often forgotten than not...


Moulds ...or molds, a.k.a. 'Casting for dummies'
Making molds is super easy. All you need is cheap silicone, cheaper corn starch and a blob of acrylic color. Plus, lots of hands cleaning afterwards.
This thread will index the process and results postings, not everything I made later with these casts.

Initial casting experiment
Here, here, here, here, here,




2nd mold run
Here, here, here, here (first time using hotglue instead of clay!), here,




3rd batch
Here and here




Casting clay bricks with Mon Cherie packing
Here




Casting eroded ruins with Miniature plastic packing
Here, here, here,




Silicone-batch, the 4th
Here, here




Making hotglue-copies of the flying basalt islet
Here




Mechanical stuff and more basalt-terrain copies
Here, here, here




May the mold be with you...
Here, here, here, here




Casting miniature bases
Here, here




The living floor mimic
Here, here, here,




Machine parts
Here, here,




...you guessed it: More molds.
Here,

[tauster]

My latest casting project was a completely different method than what I did so far. I had stumbled over an awesome Instructable for a lamp made of wood and epoxy resin, and fell instantly in love with the design:

 

So cool! I had epoxy resin casting on my OMGWANTTODO! list for years now, saved dozens of pics from pinterest and other sources, and this lamp finally shoved me over the edge. So I shelled out some serious crafting bucks and bought 3kg epoxy resin, mold release wax and some hard melamin boards (they're actually not plated with melamine but something else; these boards are used for screen printing).

I also bought a piece of poplar with a really nice wood grain, which I polished up to 1000 grit. You see, I really wanted that lamp.



I then realised that it wouldn't be very smart to start my first experiment with that cool piece of wood, so I looked for something else. I found a very weathered piece of wood that was eaten up by all kinds of funghi and worms and looked fantastic. It fit snugly in a 125mm plastic tube scrap I had left over from installing the exhaust hood in the kitchen, leaving only a few mm on each side for the resin to pour around. I used hotglue to seal it from the outside and polished the inside surfaces with the wax twice.



The only downside was that I would need quite a lot of resin to fill the tube up. Turned out that I had to use almost 3/4 of the stuff, making this an expensive first step!

I mixed the stuff in a 500gr cup, stirring for 2 min as per the instructions. What I didn't do was waering gloves, partly because I didn't have them in the shop (forgot to buy some) and because I like having more control when working with un-gloved hands. I cleaned every small speck I got on my hands immediately, but I should probably protect my exposed hands better in future epoxy games.

The ratio was 100gr resin and 55gr hardener/catalyst, so that 500gr gave me 300gr resin and 165gr hardener. It filled up the bottom 20% of the tube, even though the piece of wood was at it's broadest dow there. It tured out that the wood soaked the resin up like a sponge. I waited for 10 minutes without anything happening. The label said that it would cure in about 1 hour, so I decided to leave the shop and check later. After 1 hour the resin was hardened, but there were large 'clouds' of teeny tiny bubbles that did't look very aesthetically pleasing. Meh...



I repeated the pouring 4 more times and discovered that with that amount of material it takes about 20mins until the stuff suddenly gets hot in about 2-3 mins. Really hot. You could still touch the outside of the pipe, but the wood (or the resin?) started to puff out little clouds into the air. I was surprised that the stuff didn't stink, only a slightly chemical smell. Which was good because it reminded me not to breath too close to the resin. I had opened two windows and had very good ventilation, but still.

The warmth heated up the wood, which released bubbles into the resin which rose to the surface where I could pop them:




After about 20mins the resin started to get gelatinous in about 2 mins, then cured to a rubber-like hardness in another min or two. During that time the bubbled became trapped in the material. There's nothing I could do about it, except not using wood that had so much air trapped inside.

During the cool-down, the resin crached in some places:



The cracks look kind of interesting, but I'd rather not have them in the end result. The cracks were filled up with each new layer, except for the top layer. Meh again.

I waited for another day and then chiseled the pipe open. I was pleasantly surprised that the wax really worked and the resin didn't bond with the mold. Not that I could reuse that mold, but at least I didn't damage the casting.

The underside:



As you can see, the upper layers are more transparet than the lower ones, so the whole thing is not a total loss:


The top surface is crystal clear, and I hope I can polish the sides to a similar transparency. As per now, the best I have is 1000grit sandpaper and an orbital sander - Iguess I need some polishing paste and pads, plus lots of patience...

After the final pouring, I had some mixed resin left. For that purpose and to make more experiments I had prepared some of my cheap china silicone molds ad two self-made cornstarch-and-silicone molds. More details about them in the next posting.

Conclusion:
The end result is very far from perfect, but keep in mind that it was the very first time I worked with that stuff. I had expected far worse results actually, and I'm quite pleased with how things stand.

Heck, I could still make a lamp out of this one if I wanted to! I'm toying with the idea of sawing this cylinder into 2cm thick discs, but I have to find a way to saw this (sawing by hand is always an option, but not my preferred one). And I still have to find ways to polish it. So lots of stuff left to find out, but the start of this new road is very promising.

[Edragon]

I sense a gelatinous cube with various objects embedded coming soon

[tauster]

Jun 6, 2017 19:11:29 GMT Edragon said:

I sense a gelatinous cube with various objects embedded coming soon

Yes, that was one of my first thoughts too.

But making GQ's with embedded obects is a lot easier using pure transparent silicone: First because with the resin being liquid for most of the curing time, you'd have to wait for the very short time window when the resin gets gelatinous, or the object will either sink down to the mold's bottom or float back to the surface.

Secondly, silicone can not only be easily coaxed into various shapes (tentacles, tendrils, slime tracks behind the GQ, etc), it also is less harmful (although it stinks a lot more) and way cheaper.

Third, the fact that is stays soft and rubbery afterwards is another huge advantage when making slime-related stuff: The slime miniatures feel like actual slime. How cool is that? Try that with a fire or water elemental!

[tauster]

I try to keep it shorter this time and concentrate on the pics...




A gear butterfly. Extremely delicate structures, I didn't expext this one to survive breaking out of the mold. Of course it broke, but it worked way better than expected: it broke only one or two times. Wow!

I will try this one each time I have resin left over. No idea what I'll do with it, but this is just too awesome a piece not to try. Look at how thin these structures are!

 



An old mold made with the trusty cornstarch, silicone and acrylic color recipe. It aged and got quite stiff, so I figured that it will probably break apart soon anyway. It did. I can still use the left overs to make hotglue molds of those parts if I wanted (read: I simply couldn't throw the broken thing away.)

   


The resin cast seems to have much finer details than the hotglue castings I made so far, but I'ss see only after painting for sure.





A fresher self-made mold, only a few months old. I probably had a mixture with less starch because this one is much more flexible. One day I really have to try minimising the starch as much as possible...




The pic above shows the cured resin. As you can see, it looks extremely clear. Unfortunately the good sides are much more opaque because the mold's surface is never perfectly smooth. The castings are still awesome because they hold extremely true to the originals. The only faults are that there were tiny air bubbles trapped in some noses - which still looks fine, just like a broken-off nose that you'd expect from a weathered and ruined statue:




Suddenly I have a dozen crystal skulls. Now if there only was a story there...




Two different butterflies, some icicles and a pair of wings:



If you time it correctly, you can break the castings out of their mold and shape them a bit by slightly bending them when they are the right kind of flexible.


I mixed yellow ink in the resin while it was still very liuid. The ink doesn't mix with the resin, so you get very cool effects:



Unfortunately I mixed it too much, which killed the effect:



Also, the only crystal clear surface is the underside of the casting, so I'll either have to make casts with flat sides and later polish them up (impossible with the brain mold, sadly) or make something where the underside will be visible later on. A shallow bog with something visible below the water maybe?
 

[Draklith]

Very cool thread boss

I'm sure to employ some of these techniques soon...thanks for consolidating everything here. 

[tauster]

Glad you like it, Draklith. Can't wait what others do with resin! My own experiments have just begun, and I'm sure we all would learn a lot more, a lot faster, if we share our results and experiences.

Those crystal skulls... What if I could illuminate them all with optical fibres from one LED source? I'd have a dozen crystal skulls (or other crystal objects) that could blink or color-cycle or whatever effect I'd chose synchronously.

Even without effects, optical fibres would be a good way to illuminate multiple transparent things on a terrain board by using only one light source.

[Draklith]

Something to think about bro, I have already considered this and decided not to based on the fact if you install flickering Leds then all the pieces that you have installed them into will flicker at the same interval.

Some applications would be grand with this set up, but for my needs when I was thinking about this would have looked cheesey 

that was when I was doing the shadow boxes 

[tauster]

More casting experimentss, some successful, some not. Lets start with a failure:

I made a mold out of an expired lighbulb so that I can cast that shape, insert the old bulb's wire, maybe add some element that nobody would expect floating in a lighbulb (flowers, a miniature, a floating skull, whatever looks cool) and then light the whole thing up from below with a small LED.



At least that was the plan. I made the mold, carefully cut it open to take the bulb out and re-sealed it with silicone. When I poured the resin in, it flowed out of the bottom, where I had overseen a tiny hole. Dang! So far this project is stopped until I find another bulb to make a new mold (I have at least half a dozen of expired bulbs, but I can't find the box where I stashed them when we moved house). I'm still very much in love with the idea of casting lighbulbs, so this will probably be continued very soon...ish.

[tauster]

When the resin left the lighbulb mold, it luckily poured into a container I had placed the mold in, so that stuff wasn't completely lost. I quickly grabbed some other molds and came up with some very cool things and some that are not really failures but didn't really wow! me either.



As you can see, I played againg with mixing inks and washings into the resin. I wanted to keep the striations, so I didn't stir until all was equally mixed, instead I just spread the colors only a bit. This technique works, but only from the underside. The problem is that the upper side, i.e. where the resin sits in the molds, is never as clear as the underside (wich is amazingly crystal clear). Since the upper side is never flat, I couldn't polish it to bring out that smooth glass finish, except for very flat objects like some of the dwarven^(?) tiles:



On the upside, I finally have a completely intact butterlfy. Jay!
I'll probably paint the gears in some metal color, but I think I might leave some of the elements transparent. It is surprisingly sturdy, so I have high hopes that it will survive several game sessions.



The angel wings came out cool too. Just before they hardened, I curled in the tips and pressed them between some heavy objects so that they kept that curl (the resin has a rubber-like tendency to unbend).

The leaves came out OK, but the problem is what I described above: they'te not transparent. Meh.

The amulet molds I made months or years ago; they have hardened to the point that they lack the flexibility to survive the hard resin cast getting carefully pried out. Many small structures were ripped of, no matter how carefully I tried to pry them off. Hotglue is more forgiving on the molds, but it is never as hard and durable as the resin. I can always make new molds, should I need more of those thingies. So far I have no idea what to do with them; I just wanted to see how well the resin works with them.

And then there's this pearly/bubbly band:



Crystal clear (I just love those cheap chinese silicone molds!) and hard as acrylic glass. I'm not really sure what those will be, but I simply LOVE that thing. A lava river, an Acid Wall conjuration, ... any other ideas?

[deafnala]

It is all UBERCOOL, but I think the Floor Mimic is my favorite...so far.

[tauster]

Remember when I said that the surfaces of the cast that touch the mold aren't crystal clear but rather opaque?

Jun 6, 2017 20:38:18 GMT tauster said:

[snip] 




The pic above shows the cured resin. As you can see, it looks extremely clear. Unfortunately the good sides are much more opaque because the mold's surface is never perfectly smooth. The castings are still awesome because they hold extremely true to the originals. The only faults are that there were tiny air bubbles trapped in some noses - which still looks fine, just like a broken-off nose that you'd expect from a weathered and ruined statue:

Yesterday I took a piece that was opaque on the good side and applied a thin layer of resin over it. The result: the opaque side becomes crystal clear. Hurray! I could never, ever hope to polish resin until it gets to that crystal clear point, no matter what grain I used. But painting over it with resin? Cakewalk, no matter how delicate the texture is! Plus, you simply can't ruin anything by polishing it away. Just take care that you don't have too much resin on your brush so it fills up the finest details, that's all.

I don't have any pics at the moment because the stuff is hardening, but I have high hopes that I can show you something later this night or tomorrow.

[tauster]

The casts are still drying but I don't think the appearance will change anymore.

Before:




After:

 




That's exactly how I wanted the castings to be from the start. *happy dance*

---

And here's a lightbulb update.


The silicone mold, and the failed experiment with buttercups dipped in resin in the beackground (the petals slump, making the flowers look rather sad).




I had to cut the mold open to get the bulb out, so I wont be able to use it again. Which means that for every new bulb I need to make a new mold, which in turn means that I need a new burned-out bulb each time.

Note the difference between the crystal clear surface and the opaque sides. I had to sand the sides to get rid of the many small bumps, which got me a nice and smooth buld but made the surface look even more opaque.




And here's how it looked after painting with a thin film of resin. Perfect!

[sotf]

One thing you can do in order to massively reduce the bubbles in resin is to take a box fan, lay it between two supports so that it's facing up (For supports you can use two chairs, or even two 2x4's if you want, just leave the underside, largely, open so that it can pull air through), sit a flat board over most of the top and do your casting on that with the fan on.

It's essentially a bargain basement vibration table like while a lot of people who cast professionally use (And also works great for casting chocolate or similar if you need to)

[tauster]

Thanks for the tip, I'll remember it when I'll need to cast something bubble-free.

In the lightbulbs, bubbles are very welcome because they look like tiny twinkling stars when the bulb is lit from below.

[Lynq]

This looks awesome, I really wish I could cast for some reason I am just rubbish at it. I've never been good at mixing quantities and things like that.

[tauster]

Jun 21, 2017 13:31:52 GMT Lynq said:

This looks awesome, I really wish I could cast for some reason I am just rubbish at it. I've never been good at mixing quantities and things like that.

I bought a cheap digital kitchen scales that's exact to the gram and has a tare weight function. I wouldn't have started resin-casting without it. The ratios should be on the labels, so you can't really do that wrong, imho.

[Lynq]

I might just try that in the future, if I ever get round to it. I love the idea of casting it just seems so efficient!

[tauster]

...dammit.

Did I really have to tall into that trap? so obvious, in hindsight!

You know, Steampunk was my first love before I discovered terraninmaking and crafting monsters and generally falling into DMScotty's and DMG's crafting honeypot. I wasn't as prolific with getting stuff done as I am with crafting roleplaying stuff, but my heart still skips a beat when I see some polished brass, old typewriters and gears. I still have several kg of DIY jewellery stuff, a box full of old radio valves, and a dozen very old apothecary bottles waiting to be turned into...steampunk stuff. Plus a completely dismantled typewriter and... you get the point.

Now why did it surprise me that resing and steampunk go together that well?

That's what jumpstarted me today. Not a real beauty, but I hadn't thought about combining the two elements before that pic.




And from there it was only a few clicks on pinterest to get a sizable collection of inspirations:

   

   

This stuff will be competing with all the other casting ideas already waiting to be done. Plus the stuff I already cast (casted?) and haven't finished yet.

Live is hard. *sigh*