Rebound 25 + Sculpey Modeling clay

[Stormrider]

Can I use sculpey modeling clay to secure my source plug to the base for creating the mold?

I know some clays are a yay and some a nay, I cant find the ingredients on sculpey.

When the videos show how to make the divider and seal it with clay they never say _what_ clay they are using. Is it regular self hardening water based clay, oil based, non hardening oven bake, etc?

Can anyone tell me that knows for sure

Id wuv you forever.

Thanks
SR

 

[kanol matea]

you should really use the same type of clay that you scultped in however you can use sculpey

 

[Stormrider]

In this case, im making a copy of my scratch built helm (EDIT: starting with my MR, it will come apart a lot better) from last year, to use as a base for sculpting onto.

So I need to build up the buttom for the undercuts of the helmet, and fill some small holes/gaps with something.

I also need to fill a little gap around the visor area. Sculpey seems like a good choice cause its non hardening. I just know I read somewhere you cant use clay with XXXXXXX in it, with the rebound 25, but I didnt know where I read it

Thanks for the info. Sorry I didnt make myself clear in the first place.

 

[Stormrider]

Ok, so I looked it up instead of being lazy, and its Sulfer you dont want, which Sculpey doesnt have. So thanks for the info it led me to look it up.

I guess I never really thought about it, but will Ease ReleaseTM 200 work to make a 2 part mold, for dividing the rebound 25, or do I need a wax.

I saw originally FP's two piece helmet mold, which was superbly built. With the two piece mold, with the dividing line of the ear caps, with nice registration shapes all the way around.

I can surmise how he did the entire mold, but im curious how to divide the two silicone halves.

I would pm him directly, but he has a lot going on, and I dont want to bug him.

Anyone know for sure if I can use ease release 200 or if i need something different to seperate the two halves of the mold?

Thanks for your time, as always its much appreciated.
sr

 

[stormtrooperguy]

if you are molding a fett helmet... why would would you want to put a seam into the rebound?

my helmet mold is 1 piece... peels on and off like a glove. that way there are no seams to worry about.

i divided the plaster jacked with modeling clay, since that does have to be split.

one thing to remember is that tutorials are really just guides. you have to look at what you are doing vs. what's happening in the tutorial and see what applies.

you can see some pics of my mold making here:
http://stormtrooperguy.com/gallery/thumbnails.php?album=284&page=3

 

[Stormrider]

Thanks thats helpfull. Silly question though I suppose. Is there a split up the back of yours with a seperation line? Or is it fully a glove?

if you are molding a fett helmet... why would would you want to put a seam into the rebound?

my helmet mold is 1 piece... peels on and off like a glove. that way there are no seams to worry about.

i divided the plaster jacked with modeling clay, since that does have to be split.

one thing to remember is that tutorials are really just guides. you have to look at what you are doing vs. what's happening in the tutorial and see what applies.

you can see some pics of my mold making here:
http://stormtrooperguy.com/gallery/thumbnails.php?album=284&page=3

 

[stormtrooperguy]

Thanks thats helpfull. Silly question though I suppose. Is there a split up the back of yours with a seperation line? Or is it fully a glove?

fully a glove... no split at all.

 

[Stormrider]

I was only concerned that taking it out before it would fully set, would cause it to deform.
But ill take your advice and do it your way. I have only made small molds, a long tiem ago as a school project. Never something this big or more to the point, never anything I cared about the outcome

 

[stormtrooperguy]

I was only concerned that taking it out before it would fully set, would cause it to deform.
But ill take your advice and do it your way. I have only made small molds, a long tiem ago as a school project. Never something this big or more to the point, never anything I cared about the outcome

You don't take anything out before it's fully set. You absolutely have to let the silicone cure fully before you do anything to it.

The Rebound 25 can stretch a lot before it tears. The Fett helmet is generally pretty flat... so it's within the ability of the material to stretch enough that you can peel it off without damaging it. You just have to be REALLY careful about thickness. Too thin and it will produce lousy copies. Too thick and it won't stretch well. Follow the recommendations from smoothon exactly and you'll be fine. I want to say the goal is about 3/16" thick overall.

You also definitely want some of the THI-VEX thickener so that you can make up a paste out of the rebound to fill in some of the troublesome areas, like the keyholes and visor.

It took me 2 tries to get a good mold... I used an entire gallon of the Rebound before I was done.

 

[Stormrider]

I played with the rebound 25 last night. Everything was really a lot easier than I thought, except not making a mess

I ran into only one problem, and im think I am going to be scr3w3d.

I fell asleep.

I got really good coverage all places but one spot in the dome. You can see its thin there, I had thickened some, and packed part of the mandible area, but then fell asleep before I did my last coat over that to smooth it out

Im assuming, feeling it this morning that once the silicone fully cures, you cant add to it.

All indications everywhere I have looked says 'add at 60 minutes when tacky'. Never mentions 'once cured, your all done' but im assuming thats the case.

I did read once that somewhere you could 'repair tears with more silicone' but im thiking thats a different type of the rubber. I think it was the 40, whych is poly based.

So just to triple check, you cant add rebound 25 once fully dried. ill need to redo the mold correct?

Thanks
sr

 

[evan4218]

This is not the case with Rebound 25, you can add to it later, in theory it will be less strong but one a couple of molds that this happened to me on, there was no issue, silicone sticks to silicone and this particular one dosnt seem to excrete alcohol like the cheaper ones so bonding after the fact isnt really an issue. Also, if you think it only needs one more coat, give it two, you can get a way with it being a tad thicker then you would like and still get great molds from it, if its to thin, then its toast!

 

[Stormrider]

Awesome and thanks a lot evan. I actually used the mail you sent me 6 months ago when I ordered all my products. Hopefully when I get my plug out, cut it up, and reshape it all, ill do you proud

 

[stormtrooperguy]

if its to thin, then its toast!

i learned that the hard way!!

if it doesn't tear, the weight of the resin as it cures will pull it down, forming dimples and dents (that you don't want, as opposed to the dents we like!)

 

[Stormrider]

i learned that the hard way!!

if it doesn't tear, the weight of the resin as it cures will pull it down, forming dimples and dents (that you don't want, as opposed to the dents we like!)

Hell, thats probably how we got the dent in the first place

 

[Gypsyboy]

This is not the case with Rebound 25, you can add to it later, in theory it will be less strong but one a couple of molds that this happened to me on, there was no issue, silicone sticks to silicone and this particular one dosnt seem to excrete alcohol like the cheaper ones so bonding after the fact isnt really an issue. Also, if you think it only needs one more coat, give it two, you can get a way with it being a tad thicker then you would like and still get great molds from it, if its to thin, then its toast!

That's my philosophy as well... if you think it needs one more coat, put two. There is a fine line between making your mold thick enough and conserving expensive mold material. On the other hand, if you plan to use your mold for any amt of time then you're just gonna end up spending more in the long run because you'll have to make a new mold before long. I learned that the hard way.

I have found no problem with applying more coats over rebound 25 even months after the previous one. Silicone sticks to silicone like crazy. Nothing else sticks to it - like crazy.

 

[Stormrider]

Thanks to all of you, as you probably saved me a lot of time.

I know this project sounds dumb, but I want to have something reproducable, that I can sculpt on top of. And more to the point, machine into.

Im also going to be throwing some 'old school' nods into the build, which is going to start as a basic mando helmet, and then if I can pull it off, make something nice out of it.

Im in trial and error mode atm, and your input is saving me a lot of error.

 

[BGHunter]

yes you can in therory

 

[Stormrider]

Well the mold, mother mold, and first cast is done.

The cast came out with some lumpyness to it. Rear behind ears, and a spot on the dome, is a little wavy.

One thing I learned is 1: you dont need a TUN of smoothon plasti-paste. I made the front WAY to thick.

another is smaller amounts of roto-cast is better. if you get too much rotocast, you cant get it distributed when it gels.

Im going to do 10 coats of half servings next time, instead of 5-6 full ones.

I also learnd you can only work on about 45-70 degrees at a time, if you go much further than that, you get drips etc.

All and all it turned out pretty well. I fixed the mandible lean (much like TK did in his tut).

Im going to need a better cast though, if I am going to cut it up and then sculpt in the new pieces.

Ill post a pic today, thanks again for all the help.
Mason

 

[stormtrooperguy]

for my helmets i usually do 4-5 8oz coats. it makes the helmet thin but consistent. like a vac formed plastic one.

i do get a full coat across the whole helmet... i've found the trick to not getting drips is to have very little resin in there... once you've coated the whole thing there shouldn't be anywhere thick enough really to drip.

it took me about 8 helmets to actually get them just the way i like.