Bio Options.

[Hunts With Man]

I have a sketch drawn up and posted in another thread, I'll repost it here in a follow up if the board doesn't mind. Anyway...

I want to build a Biohelmet for a human wearer, and I'm weighing options on construction. Here's where my brain sits on the options.

Sculpt and Cast:
Bonus: Leaves a permanent master behind, on the off chance I would want or need to reproduce the piece. Could potentially sell castings if the Lair likes it well enough. No chance of parts ending up floppy. Entire finished mask is a single piece.
Downside: Zero experience with clay. I'm a little overwhelmed by the options in mouldmaking and casting materials. Not really sure who to buy from, how much of everything I need, what exactly I need. Leaves a few questions about the process, but that's easily remedied by asking here when those steps arrive. Could end up being out of budget.

Foam:
Bonus: Fairly durable. Much easier construction. Templates will assure better symmetry. Lightweight. Inexpensive.
Negatives: Reproduction means a full rebuild. Non rigid without applying fixative putty of some sort. Mistakes here cost materials as much as time. Tight curves and some fine details might just not be possible.

Cardboard, cardstock, paper:
1-UP: Minus the surfacing putty, materials are basically free. Incredibly easy build. Templating again for symmetry. Also lightweight.
Doh: More glued parts. Maybe too lightweight. Potentially easy to damage. Again with the rebuilding.

I've considered conducting a few tests with HDPE, see how formable and weldable it might be for this application. I don't have any personal experience with forming the stuff. I do know that single sheets of it are solid enough to take a serious beating, though. Not just "oops, I dropped it" I mean struck full force by a linebacker sized man with a rattan club, tough. Add epoxied joints into that mix, probably less tough, but enough to survive the average mishap.

Really, I want to try sculpting one, just to be able to say I can do it, and to be able to develop that skill so I can move on to other things. Assuming nothing horrible happens, if I get a sculpt finished, can it just sit there without a time limit of some sort before I have to make a mould or lose the work entirely? Clay isn't prohibitively expensive for me, but I'm not so sure that applies to silicone, fibreglass and resin. I can save up for it all eventually, but, wantbio!

Would a few of you be willing to weigh in?

 

[Usurper]

Sculpt one, get some oil based clay, then you will not have to worry about how long it takes you. Plus i am positive, if you scuplt a bio, you will want to sculpt something else

 

[hez1]

As far as sculpting goes, if you use oil clay (e.g. chavant, klean klay or a couple of other brands) then your finished (or unfinished) sculpt can sit there for weeks or months without suffering any ill effects. For a first time sculptor, I would probably recommend the klean klay regular firmness. It's soft enough to be fairly easily workable with your fingers, but still firm enough to take good detail. The chavant soft compound is considerably firmer, and I've had bad experiences with it not curing well with certain silicones. The klean klay can be a challenge to get really smooth though...kind of a trade off.

As far as your other questions, you might find this thread useful. I haven't read all of the tutorials, but I know you will find two of mine in there which will probably be pretty useful.

This one is of a full sculpt with klean klay, followed by the molding.

This one is more recent, and is making a mold of an existing cast, rather than a sculpt, but still useful as the process for a mother mold is different, and gives exact quantities of what I used and how much it cost.

You can get some nice looking bios with the other methods you mentioned, but if you have an interest in sculpting, then the best way to go is just to dive in.

 

[troggs]

I agree with usurper and hez, sculpt a bio, I had no experience of sculpting, but after reading as much as I could on the lair, I have now sculpted, moulded and cast my first bio - it's really satisfying when it's completed, now the only problem is what to sculpt next?

 

[Usurper]

pred heeeeeeeeeeeeeads

 

[Hunts With Man]

Usurper: Somehow I knew you'd say that, again. ;>

Hez: Thank you so much for linking these. Absolutely what I needed to see. Are you still of the opinion that Plaster of Paris is good enough for a mother? I don't expect I'll need to do a large number of resin pulls for this project, if I even need more than the first, and worst case, I can always make a second mould.

I'll go price Klean Klay when I'm in town on Wednesday, as that seems to be the favourite option.

 

[hez1]

Plaster of paris works fine for mother molds so long as it's strengthened with burlap or strips of cheesecloth. I've found that it works best if you mix the plaster at a 2:1 ratio (2 parts plaster, 1 part water), dip the cheesecloth, and then squeeze it out. When the plaster gets too thick to dip the cheesecloth in, brush it onto the mold with the cheap chip brushes. Repeat this several times until you have a decent thickness of mother mold. It'll be fairly heavy, but since you're not planning on using this for repeated castings, it shouldn't be too much of an issue.

I recently made a throwaway mold because I only needed one cast, and I used plaster of paris for the mother because it's so cheap.

 

[Hunts With Man]

Grr. Okay, so all three craft/hobby stores I knew of in my area failed at clay. All I could find that was close was the Van Aken oil clay, and it felt really hard to me, so for the moment I skipped on picking it up until I could get an opinion on it. If it's sub-par, I'll look at an online source for Klean.

 

[Philby]

Plaster of paris works fine for mother molds so long as it's strengthened with burlap or strips of cheesecloth. I've found that it works best if you mix the plaster at a 2:1 ratio (2 parts plaster, 1 part water), dip the cheesecloth, and then squeeze it out. When the plaster gets too thick to dip the cheesecloth in, brush it onto the mold with the cheap chip brushes. Repeat this several times until you have a decent thickness of mother mold. It'll be fairly heavy, but since you're not planning on using this for repeated castings, it shouldn't be too much of an issue.

I recently made a throwaway mold because I only needed one cast, and I used plaster of paris for the mother because it's so cheap.

yea what he said,....

i tried on my renaissance bio ,....but didn't really know what i was doing,....
but yea the plaster and burlap version works good,......easy,...cheap
and the mold holds up as long as it's strong,....

i used cardboard covered in duct tape so it gave it kindof a " hammered " look ,.....
didn't take the time to sand and polish ,.....add details so ,....
if i could go back ,..i'd take the time to give it some love and time,.....

can't wait to see it though,....
it's motivating to see what everybody else comes up with ,....

 

[Elkman]

I've done most of my armor work by sculpting a piece out of clay, then making a silicone mold and then casting it in two-part plastic. The process isn't intrinsically difficult, but there's kind of a learning curve behind it. Here's a topic where I showed my process of sculpting and casting a bio, and here's a huntorial where I showed how to do a mold and a cast with brushable silicone.

Sculpting your original out of clay gives you the flexibility to create shapes that you might not otherwise be able to obtain with other materials, such as cardboard or foam. As you've figured out, though, there are some advantages and disadvantages to using other materials. I think once you get over the initial hurdles of figuring out the sculpting, moldmaking, and casting process, you'll be pleased with the results.

Smooth-On makes a brushable silicone starter set. The kit contains printed instructions and a DVD, the two-part silicone to brush onto your sculpt, a two-part plastic compound to make the mother mold (support shell), and then the two-part plastic for doing your casting. The kit runs about $75 or so, and you can get it at some well-supplied art supply shops like Blick Art.

Good luck, and feel free to ask additional questions.

 

[Lflank]

Cardboard, cardstock, paper:
1-UP: Minus the surfacing putty, materials are basically free. Incredibly easy build. Templating again for symmetry. Also lightweight.
Doh: More glued parts. Maybe too lightweight. Potentially easy to damage. Again with the rebuilding.

Posterboard is the route I took. If you coat it with a few layers of papier mache (made from watered down Elmers Glue) and then finish it off with a few coats of marine epoxy, it is light, but very strong. I don't worry at all about breaking it.

I have photos of the process here:
Custom posterboard bio