Im pouring a mold, maybe more on a new master like in this pic tomorrow. Who is a candidate to buy? Im looking at $10 per three. They are resin hogs and only last about 20 shots before the mold breaks

Hi Gary,

Hmmm... Gary what kind of mold are you using? What grade is the RTV? 20 shots seem a bit short. Did you over catalyse to speed up the curing time?

WC

I use slow vega bond, these might not be as bad as theyre smaller. But they generate a lot of heat as theyre solid. And I dont like using mold releases in general as most of the parts I sell are too delicate to ask someone to wash. And I never over catylise. Since I sell so cheap every drop counts. Im just hard on molds because theyre production types to fill orders

oh... I have not use Vegabond before. When I use molds for production the mold usually last about 100 copies. If i dont speed up the curing time (1:10), the mold last about 2 to 3 years. Usually commercial grade silicone goes about 600~ 1000 degrees depend on the type of grade (medical grade goes higher).

sorry about the off topic, I was just curious.

WC

I'd be interested in buying some. Have a couple of ideas for some modern dio's they'd be perfect for.
Jerry

As ever, I have an interest.

As a side question, why not do a plaster mold of them instead of resin? Reduces the cost, and also mimics the construction of the real thing. Careful packaging could allow you to ship them safely, and would also increase mold life.

Jed

I dont really want to get into the cure times involved with plaster. I was thinking, and on these, it may be time to start using a comercial mold release spray. All my other items have very little surface to stick to the molds and are too delicate to wash. The previous barriers where all surface area and would pull chunks out of the side. So Im looking at a parafin based spray.

Two possible answers to the mold release problem:

1. Use baby/talc powder applied using a 100% cotton sock (you pour the powder inside the sock and then apply it using the toe end of the sock). Sounds strange but it works well. Just makes a big mess.

2. Use a mix of vaseline and, I believe, rubbing alchohol, the 90% stuff. so far as I know, you mix it in a 50/50 ratio, spray it on with a windex-type bottle, and when the alchohol evaporates, the vaseline is deposited as your release agent without smears and whatnot.dsf I cannot veryfy the above ratio's at the moment though.

Otherwise the parafin spray sounds like a good deal. Let us know what works.

i use the Hight tear strength RTV from Alumilite........ i get a fir number of castings out of them........ I've heard good about the stuff from Smooth-on as well............