JediDefender.com Forums

Collecting => Customs => Customizing Tips and Tricks => Topic started by: Smartypants1635 on December 22, 2005, 05:02 PM

Title: General Casting Questions
Post by: Smartypants1635 on December 22, 2005, 05:02 PM
ok all got a ? mostly this is a ? for glass but u guys may know as well so im sticking it here.

i have a few molds that are ready but i dont know whick resin to use. many resins are very hard when ther done ive heard.

i was searching the tutorials on ffurg and it had one for casting soft rubber cloaks and it said to use plasti-dip it, it said it was very pliable and took accrylics well.

would this be a good resin to cast heads/helmets /arms /legs/hands/feet with because as u get more layers it loses it flexibility, so its consitency may be that of a hasbro plastic
Title: Re: casting ?
Post by: Joe on December 22, 2005, 07:35 PM
I say pvc plastic.Thats what hasbro uses for main body parts.(i asked glassman a little while ago and thats what he told me and he uses it.)Shoot him a pm and he'll give you the site and explain all of it.(well he did for me so why wouldn't he for you...)
Title: Re: casting ?
Post by: Joe on December 22, 2005, 07:42 PM
o.k. just incase ya' are wonderin' who this is (well I do hope you figured it out.)
NoMercyJoe.....No I am not some mental that stole someones password..
Title: Re: casting ?
Post by: Ryan on December 22, 2005, 07:45 PM
o.k. just incase ya' are wonderin' who this is (well I do hope you figured it out.)
NoMercyJoe.....No I am not some mental that stole someones password..

Nope, you're just some mental who made his own password and stole darth_claus' name. :P
Title: Re: casting ?
Post by: Joe on December 22, 2005, 07:47 PM
now we're talkin'.But we all do know the Santa Im talking about in futrama....right....
Title: Re: casting ?
Post by: Smartypants1635 on December 22, 2005, 07:49 PM
any way back on subject has anyone used this plasti dip before?
on there site they said i can be used to make capes and arms for figures. i
f u can use iton arms couldnt u use it on everything else?
Title: Re: casting ?
Post by: Joe on December 22, 2005, 08:32 PM
If you want strechy everthing.I'd only use it on capes and thats it.feel and bend one of hasbros plastic capes then do the same to a hasbro arm    BIG diffarence.I'd use pvc plastic like I said before for the arms.(and all other body parts for that matter)
Title: Re: casting ?
Post by: Smartypants1635 on December 22, 2005, 09:00 PM
yeah but the thivker it is trhe less movement ther is lik bendy ness
see what im sayin
Title: Re: casting ?
Post by: Jesse James on December 23, 2005, 12:54 AM
Plasti-Dip is not resin...  It's a material used for dipping handles on tools into to coat them.  It can be used for capes I suppose but I've NEVER tried using Plasti-Dip to "cast" with.  I don't even know what kind of effect it would have on a mold.  It may be polyeurethane rubber (likely is actually) and stick to your mold curing as part of it if you're using rubber molds.

As far as casting with resins/plastics, when you look into them they have shore hardness ratings you can gauge by as to the flexibility of the material when cured.
Title: Re: casting ?
Post by: Glassman6 on December 23, 2005, 11:47 AM
Smarty,  Smooth-on makes a liquid plastic that is flexible after curing.

Its called smooth cast 45D.  You mix it and pour it into your mold, then 30 minutes later when its cured, its still very flexible. It does harden over time, but not to the point of complete rigidity. Thinner pieces are more flexible.

Plasti dip is great too. But thick and difficult to spread even, esspecially if you want a form-fitting cape or coat.

Also try flex- sculpey.  Or sculpey flex... whatever its called. Its also flexible after curing.
This is the easiest way. But you have to sculpt the piece, not cast it.
Title: Re: casting ?
Post by: Smartypants1635 on December 23, 2005, 02:26 PM
yeah the prob is no one distributes casting resin in my immediate area hte closest is south denver an hour and a half depending on traffic i dont think my parnets will take me down just to get some resin  :'(
Title: Re: casting ?
Post by: Joe on December 24, 2005, 05:37 PM
Do not underestamate the power of the online store.
Title: Re: casting ?
Post by: Smartypants1635 on December 24, 2005, 06:20 PM
parents dont like buying from companys they dont know thye think theyll get I.D. theft
Title: Re: casting ?
Post by: Nirvana on December 24, 2005, 06:39 PM
Paranoid parents...they provide many a difficulty...
Title: Re: casting ?
Post by: Glassman6 on December 24, 2005, 06:44 PM
Smarty, have a friend order it and mail it to you.
Title: Re: casting ?
Post by: mastermatt24 on December 24, 2005, 06:46 PM
Paranoid parents...they provide many a difficulty...
Your tellin me...  I just had to shut down the paypal account (LOOOOng story) :-[
Title: General Casting Questions
Post by: RollaJedi on April 5, 2006, 10:26 AM
Glassman, you are truly awesome at casting!  I just gotta say that.  I've been meandering through the different posts I've missed since posting here semi-regularly (about 5 months ago) and saw all your awesome work. 
Am I missing something though?  I could have sworn I saw a guide or walkthrough on your casting techniques on here.  Can you please direct me to it?

What I'm really interested in is how you cast halves and then put them together.  I'm not sure if its in the guide or not. 

Thanks man!
Title: Re: Casting guide?
Post by: Kit Fisto on April 5, 2006, 11:53 AM
I must have missed that one as well... I've been dying to learn how to cast with the silicon molds the way Glassman6 does. Please help us out Oh grand Master of the Cast! ;)
Title: Re: Casting guide?
Post by: babyjawa on April 5, 2006, 11:56 AM
I am making a tutorial of the way I do it. It is different than his, but it works very well. The problem is that it only works for heads and helmets.
Title: Re: Casting guide?
Post by: Kit Fisto on April 5, 2006, 12:01 PM
Cool!! Im' interested, keep us posted ok?
Title: Re: Casting guide?
Post by: babyjawa on April 5, 2006, 12:12 PM
It might take a while with all of the money going into action figures right now, but I will try my best to do it.
Title: Re: Casting guide?
Post by: Glassman6 on April 5, 2006, 12:28 PM
Here one i did, back in December. Since the focus was an Comic/animated figure i posted it at Fwooshnet & IronCow.

Here is the link. (http://www.ironcowprod.com/forums/viewtopic.php?t=319)

Hope it helps. By the way, this is just how i do it, not the only way to do it.
Also, i learned this, didnt make it up, i was just sharing learned info.

Hope it helps guys.

G
Title: Re: Casting guide?
Post by: RollaJedi on April 5, 2006, 01:15 PM
thanks a ton!
Title: Casting Questions
Post by: RollaJedi on April 5, 2006, 02:29 PM
Sorry about all the posts, but these are things that've been on my mind and needed to be asked. 

How do you all (that cast) cast a torso that splits apart?  I guess what I need to know is how you get all the parts to cast that are on the inside that hold the waist, arms, and head in place?  I'm sorry if this has been asked before.

Thank you!
Title: Other 2-part mold ingredients?
Post by: RollaJedi on April 5, 2006, 05:13 PM
I guess we're all in the dark then, huh?  :)

Ok, well let me ask this.  I'm wanting to do the toy-part mold just like Glassman does in his tutorial on the iron-cow prod site.  Is there any alternative to using the silicone rubber to make the mold, something extreme like sculpy, plumbers putty, or something like that?  Or maybe plaster of paris?

I just didnt know if maybe the resin would rip up the other stuff when you go to pull it off.

Title: Re: casting halves
Post by: Jedi_Master_Ben on April 5, 2006, 05:40 PM
Hi there,

OK, here is the run down on the torsol casting... you have to seperate the original torsol apart in order to cast both halves. You are actually making two molds, on for each half of the body. Almost nobody does this because the way that the halves are sealed. They are sonicly welded together, so the only way to seperate them is to cut them apart which in most cases destroys the body. What Glassman6, Bantha5 and my self do is make a two part mold of the body halves together. Now for those who do want to cast two halves, there are at least two safe ways to go about it. One way is to brush in the plastice resin into the mold in stages, causing a shell. The more palstic you put in, the thicker the shell. Once you have the desired thickness, clean the halves, place the limbs and head and glue the halves together. The other method is to pour liquid wax into the mold all the way to the edge. Let it cool and then put the two halves together. If they do not fit, shave off the excess until they fit. Now with a wax pen, start carving out the wax to hollow it out. Using old model kits, find a male and female peg that would make the locking mechanism. Fit the two halves again for one last alignment check and then make a new mold of the wax casting. From here you will make the plastic cast and then reassemble the  figure. In either case, you are looking at a very labor intensive project and you probable only want to do a few important customs to venture into such a costly and time consumming project. This is a professional level stage of toy production and is normally way to advance for the casual hobbiest. But, if you have the time and money to invest into this area of toy production, you could turn out professional looking customs.

I hope this will help you and any others out there that maybe thinking about doing this.

Jedi_Master_Ben
Title: Re: casting halves
Post by: RollaJedi on April 6, 2006, 10:33 AM
Man, that sounds WAAAY beyond my range right now and even if I were at your level, it sounds like too much work. 

The way you all do it sounds much more to my liking.  Just curious though as to how you get the arms, head, and waist back into the holes if its all put together when it is cast?

Thanks for the help Ben!
Title: Sound Good?
Post by: RollaJedi on April 10, 2006, 03:36 PM
Hi all
I am getting ready to start my first 3-3/4" mold and casting project.  I'll tell you what I have, and please let me know if it sounds ok to you to use.

To make the mold, I'm using Plaster of Paris.  For the casting, I've currently got Castin' Craft liquid resin and catalyst. 

I will be using Glassman's techniques he used on his wife/witchblade custom figure located here:
http://www.ironcowprod.com/forums/viewtopic.php?t=319

I'm very seriously thinking of buying Polytek's Easyflo 60 to use as the casting matieral.  It seems you get the most for your money here ($43.35 includes shipping for 3.8 Lbs.
Title: Re: Sound Good?
Post by: Glassman6 on April 10, 2006, 03:49 PM
The mold stuff, will give you problems.
One, it will deteriorate with each re-use. Plus its rigid. So de-molding wont be easy.

Take the plunge and order some RTV rubber. The flexibility is great and demolding is easy.

Pretty much any of the casting supplies you buy in the stores are troublemakers and you will end up
not liking it and it will end up sitting there.
Title: Re: Sound Good?
Post by: tykrazen on April 10, 2006, 04:13 PM
Yes... to Glassman you must listen...

Seriously, he is right -- Plaster of Paris will be horrible to work with.  Invest the money in the RTV rubber.
Title: Re: Sound Good?
Post by: RollaJedi on April 10, 2006, 04:43 PM
thank you for your help.
I will probably end up getting the RTV stuff.  What do you mean by demolding though?
Title: Re: Sound Good?
Post by: tykrazen on April 10, 2006, 05:00 PM
Removing both the original and cast pieces from the mold.
Title: Re: Sound Good?
Post by: RollaJedi on April 10, 2006, 05:09 PM
is the original usually hard to take out of the 2 piece mold then?  I mean, it doesnt just fall out, right?
Title: Re: Sound Good?
Post by: tykrazen on April 10, 2006, 05:47 PM
If you have used a mold release (a thin layer of vaseline works), it is usually pretty easy to get the piece out with an RTV rubber mold.  You'll kind of bend and twist the mold a bit to get it free.  (Plaster doesn't have that flexibility and hence why it is harder to remove the piece.)
Title: Re: Casting Questions
Post by: RollaJedi on April 12, 2006, 10:08 AM
well, I tried using plaster of paris last night just to see what it would do.  Man, I DO agree with you both!!!  That crap SUCKS!!!
I oiled the crap out of my pieces with vasoline, and plaster still stuck to them.  Plus, it was a pain to get the base pieces out.  If I never use it again, it will too soon!

I want to use the rtv stuff now, but it just seems like it costs a lot for how little you get.  What do you all buy, whats it cost, and how long does it last you?  If you dont mind answering.  Thanks!
Title: Re: Casting Questions
Post by: BrentS on April 12, 2006, 10:41 AM
I seem to recall that I bought a two part silicon kit that was around $30.  I believe it was the same stuff glassman uses for his 1 piece push molds.
Title: Re: Casting Questions
Post by: RollaJedi on April 12, 2006, 11:09 AM
Since I'm following Glassman's tutorial on the other site, I went to the different sites and here is what I came up with:

For one piece molds
smooth-sil 920  $26 for 1 pint trial size (1 pint part a, 1 pint part b) at smoothon.com

For two piece molds
4 hour one-to-one silicone rubber   $31.75 for 16 oz. at micromark.com

For two piece mold (cast)
Polytek easyflo 60    $43.35 at polytek.com (I'm not sure on the size here.  Looked like a gallon maybe?)
or
smooth cast 45D, 60D    $23 for 1 pint of A and B at smoothon.com


So far, I like the 4 hour one-to-one for $31.75 for the molds and the polytek easyflo 60 liquid plastic for casting at $43.35.  About how long would something like this last if all you did were make arms, legs, torsos, heads?  I mean, would I be able to make a lot from this?

Thanks for all you alls help!
Title: Re: Casting Questions
Post by: BrentS on April 12, 2006, 12:18 PM
I have the smooth sil 620 and I have CR-300 resin (from micromark).  These supplies will last you a long long time.  The real driving force for silicon two piece molds is the size of your mold box.  The smaller the better so that you do "waste" it.  If you make the one piece pour molds like Glassman recommends, I imagine it will last a long time.  Hope that helps.
Title: Re: Casting Questions
Post by: RollaJedi on April 12, 2006, 12:24 PM
yes, that helps a lot!  Thank you!
Title: Re: Casting Questions
Post by: Glassman6 on April 12, 2006, 03:44 PM
Well i was gonna answer your questions, but BrentS said it all.

THe easy flo will last a long time. A LONG TIME. As long as you arent wasting it.
When i first got the stuff, i was using medicine droppers. So i wasted nothing.
Now a days i eyeball it, casue i'm used to using it. So i tend ot waste a bit here and there.

But it will last you. THe RTV is what i order the most.  If your mold doenst come out right...you've used alot (depending on the size of the box)   :-X
Last year, working on Star wars and Justice league. I ordered RTV 3 times.

Keep in mind, you dont have to use these specific brands. You can get all your stuff from one place and save some shipping. I use these cause i have come to like them for various reasons. But they arnet set in stone.

As for the plaster o paris, I have to say..told ya.   :P

The mold stuff, will give you problems... and you will end up
not liking it and it will end up sitting there.


Ask me how i knew... Been there. Done that. I've tried many store bought alternatives. The only thing that worked well, was silicone window caulk.
Title: Re: Casting Questions
Post by: RollaJedi on April 12, 2006, 04:43 PM
Silicone window caulk?  Did you use that as an alternative for your molds?

Yeah, I kinda hada  feeling that the plaster wasnt worth a poo, but I already had it and was curious.  SO, naturally I indulged myself and ended up nearly encasing a corps! figure in carbonite of paris!  :)

I'll look at the other brands for the stuff, but I have done this a little and so far what I'd said is the cheapest I think.  I'm kinda wanting to go the more cheaper route right now, until I'm better at it.  Then I can get picky with it.  :)

Thanks for all your help!  I needed to hear this.  Thanks!
Title: Re: Casting Questions
Post by: RollaJedi on April 13, 2006, 11:05 AM
well, thank you guys for your help and advice, but I'm gonna stick to old fashioned customzing for the time being.  I just really dont have the money to start this right now and I dont know how much I'd get to use it since free time is very slim anymore. 
Thanks though, its been very informative if I ever want to try it!
Title: Sculpting/Casting
Post by: Ner_vod on April 17, 2006, 08:19 PM
Hey guys,

I'm thinkin of startin to sculpt and cast but I really dont know how to (Except for ceramics and stuff).

what products do you people use and is there a tutorial? :-\
Title: Re: Sculpting/Casting
Post by: Smartypants1635 on April 18, 2006, 09:25 AM
Well for us beginners I get sculpy.
 It works fairly well. Then I make a mold of it cast it and then revise it a bit with green stuff putty which drys like a rock so its finished if its a one time use, then if not I go back and make a new mold, but since all my customs materials are gone I can't give pics. :-\
Title: Re: Sculpting/Casting
Post by: BrentS on April 18, 2006, 10:34 AM
Thats a pretty good overview from Smarty.  Check out FFURG.com they have a lot of great tutorials on sculpting, casting, etc. 
Title: Re: Sculpting/Casting
Post by: Ner_vod on April 18, 2006, 09:52 PM
thanx for the advice!  ;)
Title: Re: Casting Questions
Post by: RollaJedi on April 26, 2006, 11:58 PM
dang, I just cant shake it!  I want to learn molding and casting so bad still!  I may end up just getting this and trying.  Hell, its only money....  :)
Title: Re: Casting Questions
Post by: RollaJedi on April 26, 2006, 11:59 PM
I cant remember if anyone answered this or not, but what was the drawbacks on that castin craft resin stuff anyways?
And one stupid question.  Is resin just another term for liquid plastic?  THanks!
Title: Re: Casting Questions
Post by: Jesse James on May 2, 2006, 04:43 AM
More or less the castin' craft stuff is just low quality.  I've not used it a lot, just some, and the cured casts are not on par with higher quality casting materials.  Generally when something's cheaper, the quality is cheaper as the end result.

As far as resin, it is more or less liquid plastic...  Resins aren't plastics, they're not the same materials, dont' share the same properties, etc...  The plastic Hasbro uses are injection molding plastics that start as little pellets that are heated, and shot into steel molds.  Different bird, different chemical properties and things...  Just different.

But resins are very similar to plastics.  Sometimes referred to as plastics but they are different in some ways too...  Easier to work with in small doses is one of their major differences...  I have had some experience working in plastics based industry and friends in the broader industry as well as in toys, and there are differences and such.

It should be noted too, resin is a harmful chemical...  make no mistake.  I know people who've handled and worked with resin all their lives.  It's not something to just tink with lightly.  Use safety stuff.  I suggest working with surgical gloves when you work with it...  When sanding resin items, they create REALLY fine dust particles that are incredibly harmful too...  Generally it's people working in really large doses of this stuff over years and stuff, but still be cautious.  I've heard of resins being the cause of long-term health issues because of mishandling, routine skin contact, etc... 
Title: Re: Casting Questions
Post by: RollaJedi on May 25, 2006, 11:28 AM
I've received my casting and molding supplies in the mail now.  I think I'm already to start!
I was wondering, can I buy some of those little plastic syringes, like the ones that come in medicine bottles sometimes or with baby medicine, and use those (1 for each part a and b) to extract the casting liquid, then put it into the cups?  That way I get equal amounts.  But if I do this, can I wash them out and reuse them?

Oh, and should I wear rubber gloves when doing the molding and casting?

Thanks! 
Title: Re: Casting Questions
Post by: Glassman6 on May 25, 2006, 01:48 PM
Yes you should wear golves, or be near a sink so you can instantly wash your hands of any resin/plastics that touch your skin.

Secondly, Targe pharmacy. Just walk up to the desk and ask for their plastic syringe.
They hand them out to people to inject insulin.
Title: Re: Casting Questions
Post by: Phrubruh on May 25, 2006, 04:07 PM
Are they free?

Where do you get a decent number of medicine cups for measuring?
Title: Re: Casting Questions
Post by: BrentS on May 25, 2006, 04:30 PM
I pick up extra medicine cups at my local gym.  They have tons of them setting out for the mouthwash, etc.  I'm sure you can buy them in huge bulk at medical supplies stores.

Title: Re: Casting Questions
Post by: RollaJedi on May 25, 2006, 04:34 PM
in the gym!? 
so, can you wash these out and reuse them?  (the syringes)
Title: Re: Casting Questions
Post by: BrentS on May 25, 2006, 04:47 PM
in the gym!? 
so, can you wash these out and reuse them?  (the syringes)

Let me clarify.  First I'm talking about disposable medicine cups (not syringes).  They have these in the lockerroom for mouthwash, etc.  My gym has supplies for getting ready (shaving cream, combs, hairspray, mouthwash, handlotion, etc). 

I actually do almost all of my mixing using these cups and casting using these cups.  Here is an example photo:

(http://i7.photobucket.com/albums/y271/cerius31/Casting%20Parts/hanging-mold.jpg)

It shows a mold attached to a popsicle stick suspended in a cup that is filled with silicone.  I followed one of the tutorials at FFURG to make this mold.  It resulted in this casted head:

(http://i7.photobucket.com/albums/y271/cerius31/Casting%20Parts/alen-head-casti.jpg)
Title: Re: Casting Questions
Post by: RollaJedi on May 25, 2006, 05:33 PM
ah, ok!  :)
anyone, where does one find cheaper color-tints for the casting to change colors?  I looked on smooth-on and they want 11 bucks each.  Is there anything cheaper that will do the same?  How about dripping in some paint?
Title: Re: Casting Questions
Post by: Word_Weaver on May 25, 2006, 09:55 PM
Maybe some cheapo food dye? I can't imagine it being more than a buck or two for a couple small bottles of Red, Blue, Green, and Yellow together. Even less if the dollar store carries them.
Title: Re: Casting Questions
Post by: Ruprecht on May 25, 2006, 10:52 PM
Never used food coloring myself, but Micro-mark (http://micro-mark.com/) has a set of 7 pigments for 33 dollars + shipping.  That or buy individual colors for $6.30 + shipping.  I've used the blue, and it works great.  It only takes a tiny bit to achieve a solid color, so it lasts a while.
Title: Re: Casting Questions
Post by: Glassman6 on May 26, 2006, 10:06 AM
Phruby, yes the target syringes are free.

Ditto to what Ruprecht said, I use micro marks.
But you can go to home depot and get their "OIL BASED" paint pigments.... NOT WATER BASED... ONLY OIL BASED!!

They cost about $2each an you can test adding these to your mix.  I did a few times, but after going with micro mark, i never went back to them.
Title: Re: General Casting Questions
Post by: RollaJedi on June 15, 2006, 11:03 AM
Got a question for you casters out there.
Is there a trick to pouring your resin into each half of the rubber mold and NOT having it run out when you put the top onto the bottom?  Should I let it start curing a little before I put the two halves together?  For instance, I made a 2 part mold of a head the other night.  Poured the resin into each half of the rubber mold.  Put them together and as I was doing this, it seemed it 1/4 of it leaked out, I think because its liquidy.  The result was a big divit where the back of his head would be. 
Title: Re: General Casting Questions
Post by: Smartypants1635 on June 15, 2006, 11:06 AM
Yeah, I still can't get 2 part molds like that.
Title: Re: General Casting Questions
Post by: Ruprecht on June 15, 2006, 11:11 AM
Yes, let it sit for a minute or three, depending on what you're casting with. 

After I pour it in each half, I take a minute to poke out the air bubbles with a toothpick.  Normally after that, it takes a minute or two more before it's viscous enough to put them together with minimum leakage.  Sometimes I nudge the mold a bit, and when the resin appears "Jello-y," it's time to put the halves together.
Title: Re: General Casting Questions
Post by: Smartypants1635 on June 15, 2006, 11:30 AM
I have pot life of 10 minutes :-\ how long should i wait
the whole 10 or 8 or what.
Title: Re: General Casting Questions
Post by: Glassman6 on June 15, 2006, 01:17 PM
When it stars to cure, the resin usally starts clouding up.
When i see the clouding start is when i flip the molds.

I also pour with them side by side, so the flip motion doesnt have much horizontal movement to
it, just flip and press.

My plastics have a 3-4 minute cure time, so i see the clouding start imediatley after i'm finsihed pouring.
By the time i've wiped any spillage off the cup, its flip time.

If you wait too long, then you dont get as good of a press and you dont squeeze out most of the remaining plastic. That can make the difference between paper thin excess and thick excess that has to
be dremeled off.
Title: Re: General Casting Questions
Post by: Smartypants1635 on June 15, 2006, 02:25 PM
thanks GM I'll try that.
Title: Re: General Casting Questions
Post by: RollaJedi on June 15, 2006, 03:34 PM
yeah, me too! 
Title: Re: General Casting Questions
Post by: CommanderKorbra on June 16, 2006, 10:37 PM
Here's a general question. Can anyone cast some stuff for me? I need more of an advanced caster, and I need a few things casted in a certain way. I'd send the stuff to you to get a few copies of and then you can send everything back. PM me if intrested. Thanks.
Title: Question for experienced Mold/Casting people...
Post by: Straxus on October 7, 2006, 08:04 AM
I posted this question over at Iron-Cow but figured I would post it here as well in hopes that someone can help with this problem.

I have been doing some limited molding and casting for a few months now. The main problem I run into is the air bubbles in molds and sometimes the plastic resin. This is a big problem with trying to make molds of very small parts. Fingers, antennas, etc... dont always get plastic resin to them due to air bubbles. I can use toothpick or bent paperclip to get rid of airbubbles but this is not always successful or possible depending on the molded part.
A vacuum compressor would really help but most I have seen cost hundreds of dollars. Any one out there have any low cost suggestions for someone with a severely limited budget? (Preferably less than $200... less than $100 would be even better...)
Title: Re: Question for experienced Mold/Casting people...
Post by: Ruprecht on October 7, 2006, 12:52 PM
1 cheap way to reduce air bubbles in your casts is to dust the mold with baby powder prior to pouring the resin.  For molds, follow Glassman's tutorial (http://www.ironcowprod.com/forums/viewtopic.php?p=2178#2178) and pour the rubber s l o o o w l y.

Another way that I haven't tried yet is on Sarge's website (http://www.sarges-customs.com/2partrtvmolding.htm), and looks like a good way to make fairly bubble-free molds.

I have been trying pressure molding/casting lately and have had good results so far.  All the equipment cost me about 60 dollars.  The only drawback to using a pressure system is it takes a lot more time to build a mold box, at least with the method I've been using.  This list of parts is what Master Gunzz recommended, and what I use:

Pressure Cooker:  Presto 6-quart - $45 with shipping from amazon.com
Tire Valve:  Generic brand - $3 at Wal-mart
Silicone Caulk:  Clear kitchen caulk - $4 at Wal-mart
Tire pressure gauge:  Generic brand - $2 at Wal-mart
Tire pump:  Any pump, I use the kind that stand up and you push up and down, as it'd take too long to use a small hand pump.

You take out the rubber stopper in the lid and put the tire valve in it.  Then you seal around the valve and metal piece in the middle of the lid with the caulk.  When you build the mold box and fill it with the rtv rubber, just place it in the cooker, close it, and pump it up to the desired pressure.  Bantha5 once mentioned that he pressurizes to 40 psi, so that's what I use and it works well.

As for the method I've used to build the mold box and cast the part, the guys at Goregoregore.com (http://www.goregoregore.com/tutorial_05_eng.php) have some good tutorials with pictures and all.
Title: Re: Question for experienced Mold/Casting people...
Post by: Sarge on October 7, 2006, 01:34 PM
Well, thank ya, Ruprecht for the plug. Basically my tutorial is the FFURG (http://www.ffurg.com/casting_and_molding/rtv_molds.htm) tutorial, but just with pictures. The main thing I have experienced over the years with air bubbles is using patience. That is the key. Some try to rush the process and get a lot of bubbles. When pouring the resin you need a slow, narrow stream. Once the resin is in I tap the mold gently during the first 60 seconds of the hardening process.

Mike aka Sarge
Title: Re: Question for experienced Mold/Casting people...
Post by: Smartypants1635 on October 7, 2006, 03:23 PM
E-mail master gunzz, I know he has a recipe for a homemade air compressor.
Title: Re: General Casting Questions
Post by: Ryan on October 7, 2006, 08:43 PM
I went ahead and merged Straxus's thread with the general casting question thread just so this is all in one place and is easier to find in the future. :)
Title: Re: General Casting Questions
Post by: Straxus on October 8, 2006, 01:10 AM
Thanks Ryan! Though I got a little confused at first when I check on here for my thread and didnt find it...heheh. Until I saw this thread and figured it got merged I had started to assume that I was just really really tired last night and forgot to hit post before I closed the window...hehe. (I have done that alot in the past)

Thanks for the info guys! I will save this info into my collection of tutorials. Since my current supplies are almost out I will have over a week to reveiw the new information and start a new shopping list for when I get my next pay check.
Title: Re: General Casting Questions
Post by: BrentS on October 8, 2006, 11:55 AM
Sarge, that is a most excellent photo tutorial!
Title: Re: General Casting Questions
Post by: Sarge on October 8, 2006, 07:17 PM
Sank you very much. There was an instructional page that came with the kit I got from Micromark. I expanded it and based it on FFURG's tutorial and those instructions.

Mike
Title: Re: General Casting Questions
Post by: Straxus on October 8, 2006, 11:46 PM
Any you guys have suggestions for a type of clay that would work good as a place holder for two or more part molds? Need something that wont interfere with Silicone or Urethane mold cures and will not clump/stick to the origional part excessively when trying to remove it to pour next stage of mold.
Title: Re: General Casting Questions
Post by: Sarge on October 9, 2006, 09:32 AM
I use a product called Kleen Klay that I purchased from Micro-Mark (http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=80476). The 1 pound block I purchased over 2 years ago is still good. I use it, put it in a ziplock baggie when finished and re-use over and over again.

Mike
Title: Re: General Casting Questions
Post by: Straxus on October 9, 2006, 10:32 AM
Cool!
Thanks! That is a definite on my list of things to get on payday! I made the horrible mistake of using sculpey (at a lack of anything else) and it was hell getting it off the parts and was a mess. (fortunately I wasnt using silicon mold making material when I did that...)
Title: Re: General Casting Questions
Post by: Jesse James on October 9, 2006, 05:14 PM
Straxus,

What you do when using Sculpey or whatnot is mix up vaseline w/gasoline...  You basically thin the vaseline down to a really thin mixture.  You wipe it on then as a barrier between the clay and the mold rubber.  It works like a charm...  I use Sculpey 3 then for 2-part molds because it's easy enough to find and cheap in my area.
Title: Re: General Casting Questions
Post by: Straxus on October 9, 2006, 07:30 PM
Wouldnt the gasoline ruin any paint that might be on the origional peice? Not that its a huge concern but more a curiosity.
Either way thanks for the info!

As I was just waking up as I read your post I was wondering if you were giving me a formula for "Sculpey Napalm"...hehehe.