Maximum PC

What you are looking at are my failed attempts at casting small parts with home equiment and supplies. Those may look like pieces of Alien Ice, but they are actually failed castings in epoxy resin of an alien head.

Below you can see my sucessfull cast for comparison:



The problem with the good cast is it was done in a sculpie mould. So, it a one shot. The failed attemps are all done in a reusable mold made from InstaMold by Activa.

Here is a shot with a back light:


Anyone got any ideas on how I might improve the process? Part of the problem is that the mould keep bleeding water and they make the pieces look like ice cubes. I think I have lessened that, but we will see tonight when I release two more.

Manta

in bio class this year there was film type stuff that when its wet lets only particles of a certain size through. so water wen through and gell did not. i'm not sure what it was called but it seems as though it would work for that. i have no clue what it was called but it was to simulate a cell membrane if that helps. sorry it seems so general but its a start.

Yeah - I know what you are talking about. I have used it in electrolysis before. I thought about sealing the moulds, but its just the wrong type of material. I am going to go see if I can get something better. Also, the resin I am using sux. I just switched to a different one - we shall see if that helps. The problem is, the better resins are not clear and the really good resins have to be bought by the gallon and cost too much.

Manta

cellophane....the crap used in dialysis machines....

I'm not going to bother. The molding material just sux - that all there is too it. I just cast a perfect one using clay. Like sculpir though, its a one shot deal each time. AND, it would be fine but its hard to get all the clay off.

I have some pretty pricey latex material I can use. If I can get a perfect cast from the clay or sculpie I am gonna make a latex mould. But the stuff smells like rotten fish!! I hate it.

After playing with different resins, it looks like I can get a few perfectly clear ones and then a good amount of dyed ones with a frosted back. We shall see.

Manta

Manta,

Take a oil based clay and make your sculpture. Then take knife and cut it straight in half verticly. Then take a plaster epoxy and cast it over each half. Let it dry. Now fasten the 2 halfs together (super glue will probebly work) but the best way (not the easyest way) is to drill tiny holes in the sides and use little bolts to keep it together. Then pour the latex into the mold and let it dry all the way through. When it is dry disassemble the mold and you have it. This can now be painted with accrylic paint.

Isthat understandable????

all the materials can be bought and ac moore or www.monstermakers.com

I see I am not being clear. What you said makes sence - but its for a more complicated mold/casting project than what I am doing.

Mine is a one piece horzontal mold. If you look at the second picture you can see the part that was cast (in resin) using a sculpie mold. I actually have a "blank" that makes an impression in sculpie or clay or whatever. Then you pour resin into the impression. The back is flat - its supposed to be an emblem you can paint and also back light. Now, originally I casted in plaster into a sculpie mold (BTW - for those that don't know, Sculpie is a polymer clay that can be cured - I didn't cure it). It worked great and I could actually reuse the mold 2-3 time before the sculpie got distorted. That was prototyping. Plaster is too brittle to use as a casted part (although, I am considering it as a mold material).

Next, I casted resin into the Sculpie. I got the whitish part you see in the second Pic. This destroys the mold - no biggie - I just press another with the blank. The problem is, the part has sculpie all over it that is hard to remove (see the white stuff in the eyes?). Clay does the same thing, but not as badly.

So, I went with insta-mold. It make flexable molds that don't stick to resin like clay or sculpie.

Two problems - it bleeds water (its water based after all) and this give the surface of a casting an "icy look" and washes out details. The resin actually begins to float in the mold. I did some tricks and got some OK casts, but the mold shrank becasue of it. Also, the water stops the curing process at the surface of the part. My 2 hour resin took overnight to cure. My regular resin has taken 3 days. I'm not that patient.

So what I was gonna try is a latex rubber material to make the mold. This is reverse casting really.

My blank will not work for this (its big and bulky). So:

first cast a part in sculpit or clay that is "perfect" (the one in the picture has some imperfections)
then mount the part in a small box face up.
Pour the latex over the part and wait for it to set.
Pull the latex out and you should have a block of latex with an impression of the part in it.
Then I can hopefully cast resin into the latex "mold"

Problem is, latex material smells very bad!!

If the latex fail I will think about plaster. Plaster is such a pain though.

Thanks for the interest - but what you are talking about is for more complicated sculptures than mine.

Manta

PS, I put your name in the MRL for the soldering thread.

it would still work, and you would have a reuseable mold

True - but then the part would be latex (these are only the size of a 50 cent piece). Basically, I am doing the reverse of what you say (with a simpler mold).

You:
Casting latex into a plaster mold (great for large things, masks)

Me: Casting resin ('cuz plaster is to brittle) into a latex mold (great for small hard parts).

Either way, the latex smalls bad

BTW - Did you see the MRL?

Manta

nah i will check it out now and tell u what i think. Good luck

Niiiice my name is on the list and u posted the soldering thread

Ummm...I know it smells bad, and may be worse that what you're using...

But will fiberglass resin be worth a shot at all? Watching your posts and I'm learning stuff. I just have used the stuff, with some good and bad results. Some are clear, some aren't. Just curious.

Manta-

So will you peel the latex away when the resin sets, or will you try and just pull it out????


Post some more pix

BTW Thanks again for putting the soldering thread in the mrl

you might want to do some research into the jewelery industry, they have casting routines for gold and silver, (sand casting), which may help.

I Have FG resin and did some casts with it. It's not clear - its smoike colored. It has the same issues but does work better. It doesn't smell that bad. When I say latex smells bad I mean it will gag a person. After I get a latex mold I will try both material and see how they work.

Manta

I am thinking about it. Sand casting might be OK if I can get a fine enough sand. I am intentionally limiting myself to things people can easily get. If I had a vacuum chamber for example, I would have fewer problems. I will see how easy it is to get sand casting material (or make my own). I know its just sand with an addative.

Manta

those vacume chambers are expensive, i dont even think it takes much to make them. If you use latex where a dust mask.

No shit they are. I could make one pretty cheep ($300-$600). The ones you see for $10K just have a bunch of fancy parts on them. The ones you see for ~$100 are just vacuum formers (See the MRL). I thought about one of them - but I want this as DIY as possible with few expenses.


No worries there

Manta

yeah, the vacume formers were about 100 bucks for the smallest, those look even simpler.

What about Silicone or Epoxy??