Casting a Hydrospanned head

i had some do that to me 5-6 months back 2 gallons tore up 6 molds some part of it would stick

[YANOULI]

No, inside.

I suspect this is just a bad batch but i'm still waiting for someone from the supplier to get back to me.

just because something is new doesn't make it good i have purchased resin and it was bad from the start 2ed are you doing this outside? that could be a problem depending on the moister in the air

[YANOULI]

I haven't used mould release with the Hydrospan, only when i make the plastic casting and it still sticks.

these moulds are all new, i have to keep making new ones.

The plastic and rubber compounds are new too.

Apart from the cost of the wasted materials, i can't risk making a mould of any of my other master heads in case they stick too and ruin the head, so i'm at an impasse.

DO NOT USE MOLD RELEASE with hydrospan. use nothing works better, more than likely its the resin has went bad,not the rubber if your is sticking its eather a old mold and its time for it to go or resin has gotten water in it

[YANOULI]

is the vytaplex material your using a silicone or a urethane based rubber?sometimes the water in the shrinking products can have an adverse reaction to urethane mold components. Typically silicones overcome a lot of these type problems.

Hope this helps,

Chris

It's a urethane rubber.

I have already shrunk and recast one head and didn't have any problems at all
but after i made a mould of this new master head i ran out of rubber and had to order more. Since i started this using this new batch, i've had nothing but trouble.

I do have some silicone rubber that i use for white metal figures, i could try that i guess.

[shellhead]

is the vytaplex material your using a silicone or a urethane based rubber?sometimes the water in the shrinking products can have an adverse reaction to urethane mold components. Typically silicones overcome a lot of these type problems.

Hope this helps,

Chris

[YANOULI]

I'm using smooth-on universal mould release liquid with smooth-on vytaflex 20 and smooth-on smooth-cast 300.

I haven't had any problems moulding and casting heads with these items previously, it's only with the batch i bought this week.
I'm waiting for the supplier to get back to me but if it isn't a bad batch what else could be causing the rubber to stick?

[ctc]

>when i make the plastic casting it sticks to the inside of the mould and won't come out without destroying the mould

What are you using? (If you have a brand name and a chemical name for it that'd help...) I use GI1000 silicone and have never had it stick to any kind of plastic. (It DID stick to pewter once.... which SHOULD be impossible...)

Don C.

[The Bat]

Isn't there a Mold-release spray that People use? I don't know.

[YANOULI]

Guys, i'm having trouble making plastic casts of a hydrospanned head.

The first head i shrunk and moulded i had no problems with, the hydrospan head came out of the mould clean and the casting came out clean.

With this 2nd head, the Hydrospan head comes out of the mould clean but when i make the plastic casting it sticks to the inside of the mould and won't come out without destroying the mould ( yes, i am using mould release ). I have not done anything different to what i did with the first head but it just won't come out right.
could it be a bad batch of vytaflex or is there some other factor/s involved?

I've had to re-shrink and re-mould this head 3 times now and i'm getting really cheesed off with it, apart from anything else it's the cost of materials.