Casting Resin

[mushrose]

Would this polyurethane resin be strong enough to mold fingers for a My Twinn doll that is missing 4 fingers on her left hand? The doll is made of polyurethane.

I read about using Alumilite mold putty to make a mold of the fingers. Would the Alumilite work or hold up to the polyurethane resin your using? Hope to get a response from you.

[chillnhill]

@mushrose yes, the resin should be ok for that. I have also used Alumilite mold putty and it works fairly well, but can be hard to use on very small objects. Good luck!

[pollobionico]

try the spray primer Kilz from Home Despot. If any thing go over your piece lightly with a fine steel wool just to give it some tooth for the primer to stick to.

[Scorchie]

I've been trying to make and paint my own figurines, but had the WORST time getting paint to stick to my casts. It usually just peels or rubs off. Any tips you can give to help get paint to stick? Somebody suggested Auto Primer to me once, but that just came right off as well.

[bladerj]

@Scorchie see if this works for you  /watch?v=b_Bkf-m-Ui4

[Shanjaq]

Is Polyurethane Resin extremely brittle when cured? I tried to replicate a spool and the end-caps snapped off while de-molding after waiting about 15 minutes!

[chillnhill]

@Shanjaq - there are many different types and manufactures of these resins. Generally the stuff I get from Hobbysilicone is not overly brittle, at least compared to the types normally found in craft stores.

[darthspeaks]

Doesn't Polyurethane Resin shrink in the casting process? How much does it shrink if it does (what %)?

[chillnhill]

@darthspeaks - the shrinkage in resin we used is negligible in the fairly small sizes we cast. It might be more noticeable in larger pieces, but we haven't tried very big amounts.

[bonghaven]

when ur saying antique molds. Do u mean 20 years plus? or is that just lingo of the trade

[chillnhill]

@bonghaven We often come across molds that are over 30 years old. Some might might hold up to just one last casting, others more.

[bonghaven]

@chillnhill thats so kool. Its like a time machine. I just placed an order for platinum silicone. Is that a mold material that will hold with the ages?

[xHyperSoundx]

@Queenfanforever Ball jointed dolls are made of Polyurethane resin

[nhbb980]

What is the material name for a rubber type resin that you could use for model tyres?

[lindapittsburgh]

can you make some FIMO clay molds and try the resin in them so I can see how well it works as a mold?

[queenfanforever]

do you know what kind of resin is used to make ball jointed dolls?

[chillnhill]

No, sorry.

[Matjasz5]

@queenfanforever - Polyurethane resin.

[repulsive333]

@queenfanforever

Most of the time it is Polyurethane Resin. :)

[sniper168]

how do I get my final product to be black in color?

I need to get some of this stuff!

[chillnhill]

You can use Smooth-On pigment in this resin (a little goes a long way), or just paint it (acrylic works well).

[sniper168]

thnx. i just bought everything i need.

[kingjosesmith]

Very interested in learning how to do casting. What would I use to make hard plastic parts that would be able to rub against each other and last for a long time?

[darkdanu89]

Hey I got a few questions :P

Can resin be cast into rubber moulds (originally designed for lead and tin)? Can the resin damage the mould?

And what release agents should be used?

Thanks in advance :D

[chillnhill]

Yes, we have have cast this resin in rubber "white metal" molds (or moulds :-) without any issues. We don't generally use a mold release when casting into a RTV silicone mols, but have used LPS or Mann 200 when we were not sure of the mold material. Hope this helps!

[darkdanu89]

Thank you very much for your advice and quick reply :D

[henryplacido]

can this stuff makes a vinyl toy? thanks

[chillnhill]

No, it is a fairly firm resin (like plastic).

[henryplacido]

well, do you have those stuff coz i;m quite interested on making my own designer,s toy.

[wilsonmitts]

is this like rubiks cube plastic?

[dosig]

Im not into molding or stuff like that, but some how i clicked on your video and watched it. And I found it very interesting

[chillnhill]

Glad you liked it! Thanks for commenting!

[stretch34318]

you can fill your mold with rice to find out roughly how much product you need

[anonymusbob101]

Okay, don't yell at me, I have one more question? Why did you refer to them as "antique molds"?

[chillnhill]

I don't mind questions! Some of those molds (the bunny and butterfly) are over 20 years old. We have some others that are over 30 years old (platinum silicone).

[anonymusbob101]

Is this resin good for duplicating objects?

[chillnhill]

Yes, very good for quick copies (you need a mold of the origional object). We like it bacause we can work it after the casting is complete.

[anonymusbob101]

Yeah, I figured I'd need one. But, lucky me, I know how to make the molds!

[anonymusbob101]

Dang...

[Kickflip1993]

how hard are the casted pieces?

i want to use it to make rubik´s cubes.

are the casted pieces strong enough?

[chillnhill]

Well, in technical terms they are 65 to 70 Shore D Hardness. This equates to a fairly firm plastic. So, as long as the pieces are not rubbing against eachother I wuld think that they would be plenty hard.

[anonymusbob101]

I have one more question, where did you get those molds?

[chillnhill]

Some of them are very old that we bought from a candlemaker who went out of business, others we made (that is our primary business).

[anonymusbob101]

I see.

[anonymusbob101]

How does it get so hot?

[chillnhill]

It is a chemical reaction used to speed up the "gel time". Even the room temp can effect the speed the resin solidifies, speeding up if it warm and slowing down if it is too cold.

[chillnhill]

It is an exothermic reaction.

[anonymusbob101]

Oh, and how come you don't have a lot of work time with the resin?

[chillnhill]

Most castng resins have fairly short work time because they are designed to set (harden) quickly. They resin we use hardens in 3 minutes, so it had better be in the mold will a head of that. There are also 5 minute and 10 minute resins as well.

[anonymusbob101]

I see.

[tambor74]

excelent mold and demold...bye.