I'm working with tiny dolls ( they are just more appealing to me for some reason) and was wondering if anyone has had experience casting a hollow tiny. I dont want to have to drill mine because its easy to miscalculate and mess up the whole sculpt by drilling too close to the walls. Is there a way to cast the pieces with straws in the limbs and a plug of sorts in the torso?
You could use aluminum or GI wires and spray it with mold release before casting. Maybe you could dip it in a bit of silicon as well just to make sure.
My doll is going to be a tiny 6" tall little one. I have only gotten so far as casting the head as 2 parts and hollow. I have an idea on how to cast the other parts hollow as well, but I am still new and have not gotten that far yet. Regular straws for some of my needs would be too big. So I will be using plastruct rods of various diameters for limbs and such. I am also working on a very very tiny deer creature who is probably not more than 2" tall or so. I will be casting some of those parts within the coming week or two after my pressure pot is set up. I am not 100% done sculpting her yet. I think it call comes down to planning. Replicate what others do to make larger dolls hollow and do that to a smaller scale. I don't see an issue with it.
You could try slush casting? You would need a relatively quick-setting resin for this method. You would still need to do a little bit of drilling, but not as much.
@Joankagami; I took a look at the aluminum wires and they seem like they would work fine for the doll joints. They were rolled up though do you know if its possible to get them perfectly straight? @Mothi; I'm in the process of re-sculpting mine in epoxy sculpt. Currently working on base sculpts. No details yet. Its easy enough to make the torso and head pieces hollow but the limbs and joints are what's killing me. I would love to cast my doll in spring though. plastruct rods seem like a wonderful idea. they also look like they will be easier to cut than brass tubes. Will a mold release keep the plastruct rods from fusing with the resin i wonder. @Miss_Pygmalion slush casting involves swishing the resin around in the mold right? :XDI can just see myself making a mess of that. Then theres the issue with bubbles. I'm planing on casting my pieces in a pressure pot so i dont think that will work for me.
Are you planning to drill your original pieces or have them hollow? Then you only need to block off one end before molding, to have minimal need for drilling once the parts are cast.
@twigling; I dont want to have to drill at all. :XD things always tend to get messed up for me once power tools get involved because the parts are so small. lol in other words my nail beds have had enough. Drilling it hurt just as bad the 3rd time it happened. Luckily i didn't break skin. If the hole turns out too small i would prefer to use one of those bead reamer tools or even a manual drill. The ones that look like screw drivers. I know how to do it with bigger items so i have an idea of what needs to be done i just dont know what to use in terms of small tubular, rigid materials that wont stick to resin. Right now i'm stuck between using a lubed up brass rod or one of those plastruct rods Mothi was talking about earlier.
At college, we use a rag(or any cloth, folded enough so that your hands won't hurt) and run through the curved wire with our hands till it becomes straight. Sharp bends are let for pliers though. Pin vice~ with drill bits or nibs. Platruct rods sound interesting. I'll try to see if they sell those here. It will prove to be useful. I wonder though if they melt in acetone like polystyrene. That would be much easier to take out.
@Joankagami;You know melting it out with acetone isn't such a bad idea but in the same token isn't acetone bad for resin? :XD I really do need to get a pin vice one of these days. They actually have teflon tubing also. I wonder if its no-stick like teflon pans.
XD I think you will need to use a syringe so that you won't need to spill over the outside of the cast--just the hole. Teflon has texture that will catch the resin. It's better to have a very smooth tube or something you could scrape out.
I use Nylon rods (Teflon is more expensive, but works just as well) as cores in my molds, they are smooth. Can be hard to find the smaller gauges though. Remember to coat them with mold release every so often too, or they will be much harder to dislodge. Acetone can have a bad effect on some resin, but I'm not sure which ones specifically. Are you using a pressure pot for casting? If not you could use thin drinking straws as cores. If using pressure, you'd need to put something inside the straws or the pressure will crush them partialy, making it impossible to thread through the elastic.
I used to fill my drinking straws with resin and made sure both ends were sealed off with clay and would not come anywhere near the finished doll part (because resin sticks to resin and sometimes seems quite determined to find its counterpart). It worked fine, although the straws, too, have to be coated in mold release. They have a tendency to get stuck inside.
Finals are finally done :dead @Joankagami; the way i have my molds planned out i'm hoping a solid tube of sorts is all i need. @twigling; Yeah i plan to use a pressure pot. I guess i will have to look for something solid yet tubular that wont stick to the resin and is about half the circumference of a straw. @silk; not that im being lazy or anything but that just seems like too much work. I keep leaning towards Plastruct and brass rods. I think i'll experiment with both and see what happens.
Good point on if the plastruct would stick, but I will be using mold release. There sure is one way to find out and I am sure I will figure it out real soon. I will be making my silicone rubber molds for my tiny deer who is under 3" tall tomorrow if things go as planned. I wish I had more time to sculpt the leg joints, but at this size it is just insane to do while being rushed. I will be posting on my work-in-progress post for my little deer when I get started. Trying to figure out wires, hook, and stringing is making my head hurt.
I just had a weird thought. How about the ear bud sticks? ~or some other thin stick? Ah btw. I finally found a shop that sells drill bits. I'm glad that scale model shop has it. Hardware shops here don't have those--not even the tiny drill bits.
@Mothi; I saw your tiny deer sculpt in the WIP section its so tiny cute too I hope it works out great for you. I must admit i'm quite curious to see the results. @Joankagami; not a bad idea i will have to add those to my list of things to try. I had tiny drill bits too but they were too small for my dremel I'm glad you found drill bits that will work for you. Wood is porous but had anyone tried em with resin and have em not stick to the resin? I ask because i wonder if kabob skewers wil work. Or maybe if i cast those in resin. If i use mold release on resin skewers will that keep them from sticking to the resin piece?
I tested using plastruc rods and YES they are fine. I had to use my pliers to pull them out since I can't grip enough of it with my fingers. I did apply mold release so I don't know if it helped or not. Although I made certain parts hollow by either making plugs or using the plastruct rods, I didn't make the wire holes in the molds. I used a small pin vise (spelling?) to hand drill the holes. I had a drill bit small enough to drill a hole for my 18 gauge copper wire I am using. If you look at my reindeer post you can see the pin vise in the picture so you know what I am talking about. No need to add pin holes... cause if your wire is thicker it will slide out. You want it a bit snug.
Your deer came out looking awesome i see how you plugged it now. Its slightly different from what i had in mind but its cool to know that if my idea fails there are other routes to take. congrats on completing this project.
@silk; i believe it but for my parts i need something smaller than a drinking straw so it just seems a bit fiddly for me. I would rather just go ahead and get something solid and preferably re-usable.
I am so new to this. What is slush casting? and What is a pressure pot and how do you use it. Is it the same thing as a pressure cooker?
@dollsbestfriend, I believe slush casting is when they rotate the mold while the resin is curing. i could be wrong here so if anyone else knows it as something else please do correct me. A pressure pot is a device that pressurizes the mold rubber or resin virtually reducing the bubble in the cast. I'm not entirely sure what the differences between a pressure pot and a pressure cooker are but just by looking at a pressure pot they have quite a few differences. Most importantly you cant cook a pressure pot on the stove. Seeing as how the heat will affect whatever you're casting for one it just isn't a really good idea. Pressure pots work with air compressors that basically pull all the air/ bubbles out of the pot and its contents. I don't know if you can connect an air compressor to a pressure cooker so i'm not entirely sure if or how that will work. i know these are only parts of the correct answer but i hope it helps.
