my mc sculpt

[thoren]

alright so here im trying to sculpt a mc mark vi helm for use at vacuforming. so to get a start ive decided to fill half of a folded pep model with clay. and then smooth it out and carve in some details later. hopefully if all goes well, it will look nice and i can make many buckets with it

the foam on the outside is so i can squish the clay in the mold and it not bend as much/at all. i just had a cankinda laying around in my garage so i used it lol.

heres a few pics, so far i only got one half of it filled gonna do the rest later

took me about 16-17 pounds of clay to fill half of it. idk if this will add up to less than the 35 lbs recommended to sculpt a bucket from or be less yet though. im pretty sure it will be less though

yes i realize i will have all the little flaps in it but i plan to smooth those out with some extra clay or tools. what do you guys think?

 

[kerotan 36]

That is cheating!!!!!

 

[Adam]

i can't wait to see how this turns out.

 

[Reilly]

Good idea but I don't know if the clay will withstand melting when you vacuform it. Hope it works out!

 

[AoBfrost]

You dont vacuum form the clay, the clay is just to be a "play-able"shape you modify and carve then mold with plaster. Once molded, you use vaseline/release agent and pour in plaster into the first mold, take them apart,you have a solid plaster helmet, the final piece is the piece you vacuum form.

Even then, I think this will need to be done in half like you have. Working with half the helmet will be easier to vacuum form. It's nearly impossible to stretch the plastic to all the curves and detail if you tried vacuum forming the entire helmet at once in one piece.

 

[thoren]

told you i was cheating

i have to make a plaster mold to? i figured id just stick it right on the table, i tried using plaster before and i ended up not having enough and i forgot to cut it in half, its also very small lol. i think i had a pic of it up somewhere =/
but the clay shouldn't melt on the table if it's water based right? and should hold up on the table as long as it hardens to a plaster hard state at the very least yes?.

any way i bet you could use this for molding if you could stick the two halves back together after it was complete. but i dont know what the quality would be.

unfortunately my vacuform table isnt completely finished. we have yet to find a vacuum cheap enough, and the metal frame to flip the plastic is still being welded together lol. but the mold itself should be done within like a week depending on how long this clay takes to dry. ill keep you guys updated on pics and stuff as i finish

and i belive magnum, or you frost said you wanted to try this but you were going to use it for making a mold with right?

 

[AoBfrost]

If you want 100% detail, get a 5-6HP vacuum, a 2-3HP vacuum will get the shape, but dont expect sharp details like in the clay, you will get rounded and circular details.

 

[Reilly]

Oh, its water-based clay, I thought it was oil-based. Oops!

 

[AoBfrost]

You cant vacuum form any type of clay directly with hot plastic, it will melt, clay is clay and will melt with heat. I tried this before and ruined what I created, dont make the same mistake.

You will need to plaster mold it to vacuum form.

This is for stormtroopers, but it shows how to plaster mold armor pieces

http://www.studiocreations.com/howto/stormtrooper/index.html

 

[thoren]

If you want 100% detail, get a 5-6HP vacuum, a 2-3HP vacuum will get the shape, but dont expect sharp details like in the clay, you will get rounded and circular details.

well i want to get a 5-6 hp but those are like a hundred something dollars, and the cheapest 3hp ones we could find are 70$ and anything to much larger would break my budget =[ i do have two 1.5 horsepower vacuums and we were gonna try linking them together for some extra pull, have any of you tried that?

alright frost, ill make a plaster mold. thanks for the advice,and the link frost.

 

[AoBfrost]

The cost of plastic itself will be expensive.

using 3HP wont shell out the perfect amount of detail, You may end up with rounded out shapes. I'd try it on something small first, like a hand plate, test if it will such into the indents of robogen's hand plates, if it does detail perfect, try it out on a helmet then.

 

[PMS Solstice GI]

That is cheating!!!!!

Well, I don't know if you call this cheating too, but I did my helmet with pep and then I got clay and did details with that. My clay mold wasn't crooked but now the plastic is. what happened?

 

[thoren]

i honestly have no idea what you may have done wrong. im only just trying this so if i can figure out ill tell you? maybe you should PM frost or someone who has a lil more experience in vac forming?

btw thats a bit off topic. but if i knew what to tell you id be happy to help

 

[NZTK]

You cant vacuum form any type of clay directly with hot plastic, it will melt, clay is clay and will melt with heat

Sorry but that's ******* (bollocks), you can vac form over water clay fine. to melt water clay you'd have to get it well over 1000 Celsius for the silica to change state. that is so far over thermoforming plastics flash point that its ridiculous. In fact, if you can melt water clay with the heat from thermoforming plastic I will give you a medal.

I don't understand why you filled it with clay? why didn't you just fill it with plaster, then sculpt the details on the top in bondo? It works fine on a vac table. I've made pieces of armour using a similar method.

edit: Ohhhh... I see what you're doing now. It might work, but for the the hard machined edges, water clay will flatten a bit. Vaccing water clay is only really useful for knocking out a rough prototype shapes IMO. You might only get one pull off the clay buck before you need to re-sculpt it partially, so make sure you add a faux edge and raise the buck about an inch from the forming surface, otherwise your plastic will web, which will annoy the hell out of you....webbing sucks. Before you form over it, give the clay buck a good coat of silicone release, otherwise getting the plastic off without destroying the clay buck will be a nightmare. The plastic isn't that expensive at all. Get yourself a sheet of 2mm Styrene. It shouldn't cost you any more than $20 for quite a large sheet. Also I don't think forming it in two halves is the best approach, with that much height, you're going to end up with a lot of thinning. I saw a photo of a vac formed helmet kit (Westerfeild's I think?) it was done in about 4 or 5 parts. that way you end up pulling shallower pieces that will have a more uniform thickness. For a prototyping part, it might be fine though. Good luck with your project.

 

[thoren]

i filled it with clay because i origianaly thought i could just pick it up and stick it on the table. as to why i didnt fill it with plaster was because the paper isnt water proof and it would make it fall apart or deform, i tested the plaster with a small cube shaped pep piece, and it came out rounded and bent. even with the foam sprayed around it so it would stay in the right shape. and with the clay i would have more than 8 minuets to do details smoothing etc. and there is less sanding with clay than bondo i belive. and just to be safe im still making a plaster cast. i dont want to take any chances of my sculpt melting and becoming a waste of money. i may just fill the larger pieces with plaster and try to put the flaps on the outside. as for getting the clay out im working on it shrinking enough so i can just pop it out. if not ill have to try and wedge it out i guess, and try not to destroy the paper mold, i could be usefull later for something if i screw up.

and im not to good with bondo anyway. + if i can stick the two halves of the helmet together i can try and make a rubber mold from it later

and watch your mouth their are young ppl on this site to

 

[NZTK]

I havnt tried this, so it just a theory, but If was going to try to solidify a pep pattern, I'd do it like a black sand casting. Imbed the pep pattern in damp sand (maybe give it a spray with a plasticising paint first to seal it against moisture) then pour you plaster into it. The damp sand should hold it all in place nicely. once the plaster has kicked, pull it out, give it a quick bake than sculpt your detail layer in what ever medium you like, then you're either free to take a mould, or use it as a vac forming buck. Also, Id like to point out you don't need a massively powerful vacuum source for forming, I use a little kambrook jaguar vacuum cleaner, It works fine.

 

[AoBfrost]

Well, if water based clay can be vacuum formed, it still isnt a good idea, the pressure being sucked down upon it by the plastic from the vacuum would distort the shape of the clay sculpt if it isnt hard, if it's still moist, anything can damage it.

 

[Falling Jihad]

im sorry i dont know a whole lot about molding couldn't you have just taken the pep'd helmet, resined the outside, then filled the inside with expanding foam and let it set up. that way you wouldn't have had to use all that clay and still have a semi rigid structure. from there you could just detail the out side with bondo and hit it with another layer of resin to seal it all up and then vacuum form it or mold it with something else.

thats just how i would go about this

 

[NZTK]

Well, if water based clay can be vacuum formed, it still isnt a good idea, the pressure being sucked down upon it by the plastic from the vacuum would distort the shape of the clay sculpt if it isnt hard, if it's still moist, anything can damage it.

Yeah, Im pretty sure that was implied by what I said.

You cant vacuum form any type of clay directly with hot plastic, it will melt, clay is clay and will melt with heat. I tried this before and ruined what I created,

Can we see pictures of the melted water clay? It just a scientific curiosity, It sounds like you may have discovered a loop hole in conservation of energy theory.

 

[Lordmagoo]

cant wait to see the results