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Would anyone have any advice as to what method would be best to cast something like this?



granted it would be without the howda.

I was thinking I could do a split mold, like this

http://www.smooth-on.com/gallery.php?galleryid=315


IF my squigs mouth wasn't open... with the mold material getting trapped inside his face hole, I'm unsure the split method would work at all.

IF the squig's mouth was closed, I could do the split mold method I think, though I'm unsure as I've never cast anything but a fishing line, and that was only a handful of times.




So dakka, all you wise and experienced gits.


Learn me something so I can progress here!

I'm an inexperienced caster, but I would think it'd be easier to do the legs and body separate. It'd be even better if you could cut the body in half and do the two halves separate - but that might be unreasonable.

Two part mould for it, not a split mould.

That's the "easiest" way to do it. As to what resins, that varies from country to country and is mostly a matter of trial and error to determine what is right for "you" (certain resins work better than others. Certain resins require pressure/vacuum moulding for best results, etc).

I'm a beginner at resin casting and i have never cast a larger model. So my experiences are limited. But i can share my thoughts. Firstoff I'll summarize why i wouldn't cast that model the way it is. I hope to not sound too harsh.I don't want to bash your work or look down on the quality. I know that creating a larger model can be quite difficult and everyone needs to start somewhere. So hopefully you can understand it as constructive criticism so that your next approach is even better

Okay, why wouldn't i cast it?

1. First off casting a model that large will cost you a lot of mold material. As a result casting a model should only be done if it is exceptionally executed and you actually need a few of those. If you only need one or two casts think twice about casting a model. And expecially on a large model like that.

2. Then there is the problem of useing GW models as part of it. It is in essence recasting of GW pieces that are in no way converted. They are just placed on the model. I wouldn't do it.

3. The quality of the whole model could be much better. If you want to cast something the quality should be good enough that you can look at the model after a few month (or even years) and are still like the quality. In your case the legs need rework and the one in the air looks rather unfinished and wonky. The whole body could use some additional details. Either skin structure or stuff like additional leather "saddle" around the top. Also some more leather straps would be a possibility.

4.There are a few details on the model that would be trapped in the mold. And that isn't the mouth. As lond as there are no open spaces behind the teeth the mouth should be on problem at all especially on a model that large. The big problem is the chain. Each chain segment will be caught in the silicone. You'd have to either create a mold that seperates exactly around the chains or fill the insides of each chain segment and the area below it.

5. The main body is to large and you need a lot of silicone to cast it. The problem here is not only the size but also the fact that the mold needs to support a large hole in the middle. If the walls of the mold are too thin it will deform just be its own weight and the weight of the resin and the body will come out deformed.


But let's look at what i would do if i had to mold a similar model.

Create separate pieces.
The legs should be seperate pieces that are on it's own mold. Not only for better results but also to save silicone on the main body.
Also all the other parts need to be seperated. Each model can be cast seperately and depending on how much details are on the underside of the top-cage either seperate it into 5 flat parts or make a one part mold with a flat underside.

Multipiece torso.
One way of tackling the torso could be to seperate it into two sides and make two one piece molds. That way the weight on the mold walls is smaller and you don't need as much silicone for the mold. That also means that you have to put in additional work to fit both sides smoothly together but you don't risk deforming that much.

Rework the chain
Either replace the chains with a system of sculpted leather strap/harnish or you have to fill in each chain part so that it actuall can be cast. Creating a mold that runs along the chain segments would go against the idea fo creating one sided molds for the torso pieces so not the best option in my book.


Hope i could help.

I don't have much additional commentary to add here, BUT as an experienced caster, I do have to say that all of the advice here would be consistent with my experience.

Here are a few other thoughts (again, similar to the other posters).

1 - cast it in pieces, smaller molds, less undercuts, easier to work with.

2 - this would be expensive, so unless you need exact copies (i.e clones, someone wanted one just like it, etc.) or large numbers of them, its just easier and less expensive to make more.

3 - Materials - resin is somewhat expensive per unit of volume (and heavy). if you did need to make a lot of these (a few dozen?) I would consider casting the body in hardfoam (a two part hard expanding foam, used for a lot of special effects and terrain). Although this takes a bit more work in setting up the molds.

Casting can be a lot of fun (I do a lot of terrin, bases, unique parts etc. in plaster and resin) BUT does not really work out on all projects.

Best of luck!

Thank you all for so much feedback and sound advice! time to get down to replies!

 btldoomhammer wrote:
I'm a beginner at resin casting and i have never cast a larger model. So my experiences are limited. But i can share my thoughts. Firstoff I'll summarize why i wouldn't cast that model the way it is. I hope to not sound too harsh.I don't want to bash your work or look down on the quality. I know that creating a larger model can be quite difficult and everyone needs to start somewhere. So hopefully you can understand it as constructive criticism so that your next approach is even better

Okay, why wouldn't i cast it?

1. First off casting a model that large will cost you a lot of mold material. As a result casting a model should only be done if it is exceptionally executed and you actually need a few of those. If you only need one or two casts think twice about casting a model. And expecially on a large model like that.

2. Then there is the problem of useing GW models as part of it. It is in essence recasting of GW pieces that are in no way converted. They are just placed on the model. I wouldn't do it.

3. The quality of the whole model could be much better. If you want to cast something the quality should be good enough that you can look at the model after a few month (or even years) and are still like the quality. In your case the legs need rework and the one in the air looks rather unfinished and wonky. The whole body could use some additional details. Either skin structure or stuff like additional leather "saddle" around the top. Also some more leather straps would be a possibility.

4.There are a few details on the model that would be trapped in the mold. And that isn't the mouth. As lond as there are no open spaces behind the teeth the mouth should be on problem at all especially on a model that large. The big problem is the chain. Each chain segment will be caught in the silicone. You'd have to either create a mold that seperates exactly around the chains or fill the insides of each chain segment and the area below it.

5. The main body is to large and you need a lot of silicone to cast it. The problem here is not only the size but also the fact that the mold needs to support a large hole in the middle. If the walls of the mold are too thin it will deform just be its own weight and the weight of the resin and the body will come out deformed.


But let's look at what i would do if i had to mold a similar model.

Create separate pieces.
The legs should be seperate pieces that are on it's own mold. Not only for better results but also to save silicone on the main body.
Also all the other parts need to be seperated. Each model can be cast seperately and depending on how much details are on the underside of the top-cage either seperate it into 5 flat parts or make a one part mold with a flat underside.

Multipiece torso.
One way of tackling the torso could be to seperate it into two sides and make two one piece molds. That way the weight on the mold walls is smaller and you don't need as much silicone for the mold. That also means that you have to put in additional work to fit both sides smoothly together but you don't risk deforming that much.

Rework the chain
Either replace the chains with a system of sculpted leather strap/harnish or you have to fill in each chain part so that it actuall can be cast. Creating a mold that runs along the chain segments would go against the idea fo creating one sided molds for the torso pieces so not the best option in my book.


Hope i could help.

1. The casting material cost is a big concern for me. I had considered even buying ping pong balls, or something cheap and similiar to "throw away" and create a hollow portion inside the mold? though unsure that it is feasible. I had thought even a balloon could be used? securing it in place, inside the cavity of the mold seems to be an issue though.

2. if I did cast something this size, it wouldn't include any GW parts such as this fanatic. This thread is primarily about something roughly the size and shape of that, with an open mouth vs. closed so I can identify problems and hopefully make "the one" to cast without wasting alot of precious time and materials. I had hoped since these are a generic enough type of creature, and if I didn't use any IP infringing words, that they could potentially be a marketable product as some sort of a fantasy beast creature.

3. My materials to sculpt one incluidng base comes about $15 (damn GW bases $5 a piece), so really $10 of material in the model itself, +3.5 hours to finish it w/o a howda. I have 4 giant manglers like this, 6 aracknaroks, and 10 colossal squigs, all of which will be unique sculpts. I figured that since I am doing so damn many, I could probably get 1 or 2 to a quality that I would be proud enough to cast. Friends at my FLGS have expressed interest in buying some, and offered about $60 a pop for them, and that sounds fine, unless I have to include a howdah, which I couldn't do for that price. Again, the model here is not actually "the model" to cast. As you can see, its not even finished in this photo. I don't actually have a photo of the complete guy, he's halfway painted though so, hehe he won't be the one I'm casting up. I'm of the belief, you need to do 10 of something before you have any clue of what you are doing, and this is definately not #10. I think I have 8 or so, and they are mostly only up to half finished. This was my first actual complete one (though its pictured incomplete).

4. I didn't realize the chain would be such a prolem. I will use rope/twine in future. That should be easier right? The issue is... there IS a BIG space behind teeth, with a big happy tongue now.. Not pictured.. Sorry. Been a while since I took any hobby photos... So seeing as there is a big air gap behind teeth for mold to get trapped into... how does one deal with that? Seems like open mouth isn't feasible for casting, which is what i was thinking. I had though a closed mouth would be about the only thing I could realistically achieve.

5. Yeah I am at a loss at how to make something this size, that won't be so heavy that it will bend the legs.. or how to realistically get a holow/void inside the model while maintaining integrity.



When making two 1 sided molds, I suppose that would be quite possible but would leave some gap filling/greenstuffing most likely left up to end consumers... but on a model like this, that wouldn't really be too much detail to fill in I would think. Would y'all agree?

I figured I would have to create separate pieces. I was thinking I may have to cut lower jaw off even, to allow for cavity behind teeth?

Thanks doom!




Automatically Appended Next Post:

davethepak wrote:
I don't have much additional commentary to add here, BUT as an experienced caster, I do have to say that all of the advice here would be consistent with my experience.

Here are a few other thoughts (again, similar to the other posters).

1 - cast it in pieces, smaller molds, less undercuts, easier to work with.

2 - this would be expensive, so unless you need exact copies (i.e clones, someone wanted one just like it, etc.) or large numbers of them, its just easier and less expensive to make more.

3 - Materials - resin is somewhat expensive per unit of volume (and heavy). if you did need to make a lot of these (a few dozen?) I would consider casting the body in hardfoam (a two part hard expanding foam, used for a lot of special effects and terrain). Although this takes a bit more work in setting up the molds.

Casting can be a lot of fun (I do a lot of terrin, bases, unique parts etc. in plaster and resin) BUT does not really work out on all projects.

Best of luck!

First off, thanks dave for the time in replying!

1. Yeah pieces is what I'm thinking will be required. I could use a more light weight resin for torso, and more rigid one for legs even??

2. Well for my time and materials I'm thinking about $60 for these for my franz. but I figure that price could come down if I could get it cast in a cost efficient manner and skip out on 45$ of my labor. Or at least my thoughts at least. Plus pouring some resin letting it cure and collecting $ is a whole lot less labor intensive than sculpting a unique one each time I would think? I'm always very short on time so I figured if I could get away with casting something, why not?

3. Thank you very much for hardfoam idea. Could use more rigid resin for legs, and hardfoam for torso as its lightweight perhaps? though I need to research the chemical effects of the more popular paint stripping methods so that these can be stripped by the consumer in event they resell/repaint them over time. Selling one off's made of greenstuff and miliput make me worried slightly that my consumer could resell it one day, forgot to mention that you can't strip it using normal methods and not destroy the model.. (i haven't found a safe method for stripping GS/miliput without harming it... heard rumors of acetone but no confirmations that I read)




Automatically Appended Next Post:

rigeld2 wrote:
I'm an inexperienced caster, but I would think it'd be easier to do the legs and body separate. It'd be even better if you could cut the body in half and do the two halves separate - but that might be unreasonable.

do you think that consumers would "mind" if there was a gap requiring some GS work to make this thing more light weight?

I figure that some organic leathery skin can be patched over by inexperienced users a lot more so than a gap in say, scale armor of chaos dwarves or something.


thanks!

1. The casting material cost is a big concern for me. I had considered even buying ping pong balls, or something cheap and similiar to "throw away" and create a hollow portion inside the mold? though unsure that it is feasible. I had thought even a balloon could be used? securing it in place, inside the cavity of the mold seems to be an issue though.

Well i had this idea. Not sure how viable it actually is but it might just work. Build the whole body as a two piece mold but before you actually cast fill both sides only partially with resin. Then if the resin starts to cure press the filler in. Then in a last step assemble the mold sides with the mostly cures resin and pour in the middle part of the resin. This might be a way of getting the filler in without it touching the mold walls.

4. I didn't realize the chain would be such a prolem. I will use rope/twine in future. That should be easier right? The issue is... there IS a BIG space behind teeth, with a big happy tongue now.. Not pictured.. Sorry. Been a while since I took any hobby photos... So seeing as there is a big air gap behind teeth for mold to get trapped into... how does one deal with that? Seems like open mouth isn't feasible for casting, which is what i was thinking. I had though a closed mouth would be about the only thing I could realistically achieve.

Well just look at models with open mouths GW has. They all have the mouth in multiple pieces. You could try and create an open mouth without lips teeth and tongue. Then you have to create the inlay with those missing details as one part. Or make the entire lower jaw a seperate piece.

5. Yeah I am at a loss at how to make something this size, that won't be so heavy that it will bend the legs.. or how to realistically get a holow/void inside the model while maintaining integrity.

Well if you really want to make a bunch of casts it is a good idea to keep the resin usage low. So maybe create the whole body as a multi piece part that is in itself hollow by design. Just look at the larger GW beasts. They aren't just massive blocks of plastic.
That would mean that you have to create a two sided mold for each bodypiece. The model would be much lighter but you might have to integrate some internal structure like a pin in each part which interlock and can be glued as you assemble it.
Creating a model like that however will be quite tricky. You probably need some sort of hollow main body that is stable enough to sculpt on but can be cut into parts without loss of details. What you could try is build the main body like you did but leave the details simple. Then cut it into pieces and remove the inside. Glue the pieces together for the actuall detailwork. Just be carefull and create the details so that they don't cover the gap. Then if you are finished you should be able to break it into pieces at the seams and cast those seperate.

And if you still fear that the legs will be to instable maybe include some scenic basing piece underneath the body like some crumbled rocks or stoneformations or whatever. Because you also have to keep in mind that the final product has glued legs. Either force your customer to pin those or think about the scenic additions.

Can't believe I forgot to reply to this, ugh life.


Thank you for the well informed response doom hammer.

I have been working on mold designs recently on how I could do this. I think I may have figured something out.

so this is my idea for a mouth closed hollow squig

start with foam ball, cover with thin layer of tin foil.

sculpt squig on this, cut in half as you mentioned

now that you can see a cross section of the model you'll see (from exterior to interior): putty-skin, foil layer, foam core.

You can now pluck the foam half-sphere out of the model (and pick the tin foil out to, whatever isn't stuck to the putty.

repeat step for back half of squig

now we have 2 hollow halves, we know the sphere we pulled from the interior "fits" inside so it could be used to make a negative to "fill" the shell of the real model. I figure I could cut 1/4 inch off the flat portion to increase the wall thickness of the model as well?

now you would have 2 "halves" of a squig that are hollow. the consumer would have to glue them together and possible GS the seam a bit but... I figure well worth it in reduced cost of resin and weight

I figure i could split the squig down his body longways on the ones with open jaws. Will have to construct the innards of foil so I can scrape it all out of the shell, and will have to custom build negative inserts to create a hollow portion in the body cavity


as for the mouth pieces I'm fairly sure I will do the separate lower jaw as you have mentioned. it seems the best way to do it.

I have been looking more closely at the work done here http://z3.invisionfree.com/Orc__Goblin_Warpath/index.php?showtopic=31244&st=0

he uses pegs to insert into the model as pins for the legs... now.. i'm confused, i thought the pegs would be filled with the mold and trap it forever?


Automatically Appended Next Post:
just found this, which is extremely helpful.


http://atelierpoupee.blogspot.com/2010/12/mold-making-tutorial.html