Mold Substitutes

[Nintendude]

Hi All,
I was wondering what if any mold substitues instead of stuff like Rebound 25 for people with a low budget can use and what the application process is for the material. I've heard that 100% latex that comes in the tubes from a hardware store can be used but what is the best way to put that on, what are other materials that can be used for making a mold and thier processes?

 

[Korydabomb32]

I think you should get heavy duty latex. You can buy it in huge cans, like paint cans. You brush it on layer by layer, and by your 20-30th layer, you can make a mother mold out of fiberglass or plaster. Latex is amazing for a cheap mold maker.

 

[Beau Nidle]

Yup, I have some stuff called castin craft latex mold builder. It was about $40 for a gallon. I don't love it, but it does the job on a budget.

 

[B1ahh]

rvb18 had this posted up. Recently tried it on his Reach knees.
http://www.405th.com/showthread.php/25191-a-good-tut-on-how-to-make-a-cheap-mold-from-caulk
(3 parts. Just click the vid to find the others)

Thinking of trying it too on some ODST parts.
Hope it helps

 

[rvb18]

as B1ahh said i did post that and have tried it with fiber glass casts. it works great! i used the cheap $3 silicone caulk from wal mart

 

[MrTiKi]

RVB how many tubes did you end up using?

 

[tompkins420]

and how was it applied? did you need a release agent? i think that would be the best cheapest way to make a mold

thanks for the insight

 

[MrTiKi]

I think you should get heavy duty latex. You can buy it in huge cans, like paint cans. You brush it on layer by layer, and by your 20-30th layer, you can make a mother mold out of fiberglass or plaster. Latex is amazing for a cheap mold maker.

There is a really thick marshmallow type paint at the hardware store but I cannot remember what it is called. Was at lowes. Super thick stuff. Would probably be great for this. Also I bought some latex caulk at wallyworld $1.28 a tube pretty cheap if you ask me.


EDIT: Found it, but with a name like gripper I bet it will be tough to get it to release smoothly, so scratch that.

http://www.homedepot.com/Paint/h_d1...splay?langId=-1&storeId=10051&catalogId=10053

 

[23Magnum]

I actually had a discussion about latex molds vs silicon molds with Sean last weekend. The thing with latex is that it will break down over time. So molds done in latex should not be considered for a long storage life. Silicon of course lasts a really long time if cared for properly. The silicon caulk idea is good for small molds. When you start doing items larger than...your head let's say...the cost benefit starts to declined with all the extra work you have to do to use the caulking.

You might also want to check out Alginate as a possible one time mold source. It's water based and much cheaper than silicon. It's not dirt cheap though and it's a one time use kind of material. Usually you'd only want to pour plaster casts in the stuff, but you are supposed to be able to cast some urethanes and similar products as well. I have bought mine that past couple times from this site: Accu-cast.com.

Sean and I did both my hands in the stuff and cast them in a plaster material. It gets a crazy amount of detail.

 

[soul products]

magnum is right about the alginate, its only good for one cast but it picks up tons of detail. its the same stuff they use for dental castings. as for the caulking method, i cant give it many good comments. even with a release agent it still tore and stuck onto all the masters which left holes in the mold therefore messed up the castings. i havent tried it with clay so i cant say anything about that but i dont give it high marks. it set me back weeks with my mark IV suit. use at your own risk 25% chance of working halfway decent

 

[MrTiKi]

magnum is right about the alginate, its only good for one cast but it picks up tons of detail. its the same stuff they use for dental castings. as for the caulking method, i cant give it many good comments. even with a release agent it still tore and stuck onto all the masters which left holes in the mold therefore messed up the castings. i havent tried it with clay so i cant say anything about that but i dont give it high marks. it set me back weeks with my mark IV suit. use at your own risk 25% chance of working halfway decent

Did you caulk with latex or silicon??

 

[soul products]

silicone and the acrilic hardener shell

 

[p0g1]

looks like the smooth-on products are the way to go

 

[soul products]

looks like the smooth-on products are the way to go

definitely

 

[beaker]

Thing to consider about latex molds, they shrink... if you ever bought an ebay recast of anything chance are it is smaller than the original... a good cheap mold material is PMC-724... will only last a couple of years before it completely breaks down but a gallon kit is under $58 (http://www.smooth-on.com/Urethane-Rubber-an/c6_1117_1145/index.html) As with any of our products shrinkage is almost non-existant... the one part caulk silicone actually costs more per gallon than anything we sell and being a one component system makes it very hard to process, voids and air gaps are bound to be an issue...
just food for thought

 

[tompkins420]

hey beaker...how does this compare to rebound 25?
thanks

 

[beaker]

rebound is a silicone, so the processing is different...nothing sticks to silicone and silicone doesn't stick to anything but other silicone, urethanes want to stick to everything and everything wants to stick to them... it is the biggest difference... 724 is a 10:100 by weight, as opposed to 1:1 by volume for rebound... 724 has it's own thickener so it can be brushed on or poured... you will need mold release at all times but otherwise it picks up the same detail and not hard to work with... one other thought though.. unlike rebound that can be layered at your leisure, urethanes need to be layered on (for brush up molds) before the layer underneath completely dries or you could have delamination... this stuff is general info for all urethane rubbers... still makes for an awesome mold material... Dick Smith used PMC-724 for almost everything he did...

 

[soul products]

beaker- does PMC 724 NEED de-gasing or does it do fine without it? you got me interested. also, would something like petroleum jelly work as a release agent and would an oil based clay need a release agent?

 

[beaker]

Urethane rubber in general does not ever need to be degassed and 724 is no exception at 4000 cps it is a nice low viscosity liquid... you could use petroleum jelly as a mold release just make sure to use it sparingly and not clump it on... I would still release the clay... universal mold release is a good choice

 

[rvb18]

silicone caulk is a great sub. you just cant be dumb when using it. there's a trick to not have air bubbles and this guy found it.

as for how many tubes i used for that knee. 1 half