retroguy Posted May 27, 2018 Share Posted May 27, 2018 I've been using smooth-on silicone to make molds for casting hard to find small parts... does anyone do casting and what do you use...thanks Quote Link to comment Share on other sites More sharing options...
Ace-Garageguy Posted May 28, 2018 Share Posted May 28, 2018 I've used multiple products from both of these companies. Never a problem, everything first rate. https://www.freemansupply.com/ https://www.polytek.com/ Quote Link to comment Share on other sites More sharing options...
retroguy Posted May 28, 2018 Author Share Posted May 28, 2018 (edited) what silicone do you use from these companies that are best for parts... the other thing is that I use 1:1 silicone,it's much easier for me... Edited May 28, 2018 by retroguy Quote Link to comment Share on other sites More sharing options...
Chariots of Fire Posted June 25, 2018 Share Posted June 25, 2018 Micro-Mark sells 50:50 two part mold making RTV. it is easy to mix and sets up well in about 4 hours. Not cheap but you can get quite a few nice molds from one package. If you do two part molds you would need to purchase some mold release agent as well. Quote Link to comment Share on other sites More sharing options...
Khils Posted June 25, 2018 Share Posted June 25, 2018 9 minutes ago, Chariots of Fire said: If you do two part molds you would need to purchase some mold release agent Good Sir! I am in need of said " silicone to silicone" mold release..... do you have suggestions ....seen a few listed & have been pricey. Quote Link to comment Share on other sites More sharing options...
Chariots of Fire Posted June 26, 2018 Share Posted June 26, 2018 Micro-Mark does have it. I am not sure if ordinary silicone spray would work or not. I have not experimented with it. Quote Link to comment Share on other sites More sharing options...
bill w Posted June 26, 2018 Share Posted June 26, 2018 I've been making molds for 20 years...I always use petroleum jelly for rubber to rubber release. Never had a problem. All you need is a thin coat! Quote Link to comment Share on other sites More sharing options...
ChrisBcritter Posted June 27, 2018 Share Posted June 27, 2018 I tried the white Smooth-On resin and it worked pretty well, except that both bottles needed to be shaken before use. This gave me a lot of problems with bubbles forming once mixed, and I don't have a pressure pot, so I switched to the Alumilite slow set. So far I have less bubble trouble. Quote Link to comment Share on other sites More sharing options...
my66s55 Posted June 27, 2018 Share Posted June 27, 2018 I've used Smooth On resin for 10 + years. The secrete is to pour parts A & B in their individual containers and wait a bit for the bubbles to go away. If then you use a pressure pot, you will get excellent parts. I also use petroleum jelly for a release agent. Quote Link to comment Share on other sites More sharing options...
BigTallDad Posted June 27, 2018 Share Posted June 27, 2018 Will coating the part to be casted in WD-40 work? Quote Link to comment Share on other sites More sharing options...
BigTallDad Posted June 29, 2018 Share Posted June 29, 2018 On 6/27/2018 at 7:13 PM, BigTallDad said: Will coating the part to be casted in WD-40 work? Or perhaps cooking spray, such as PAM Quote Link to comment Share on other sites More sharing options...
crazyjim Posted June 29, 2018 Share Posted June 29, 2018 I use Smooth-On and baby powder as a release agent. Quote Link to comment Share on other sites More sharing options...
Art Anderson Posted June 29, 2018 Share Posted June 29, 2018 13 minutes ago, BigTallDad said: Or perhaps cooking spray, such as PAM When I was doing All American Models, I simply used Vaseline petroleum jelly, about 1/4 tsp of that to a 4oz jar of ordinary enamel thinner--to coat the cavity and top surface of the first half of my molds, worked EVERY time without fail. Nowadays, on the rare occasion that I might duplicate a model part for a project, I still use it and it still works. Very inexpensive too, I might add! Art Quote Link to comment Share on other sites More sharing options...
Snake45 Posted June 30, 2018 Share Posted June 30, 2018 Alumilite has a 2-part silicone putty that is VERY easy to use. You knead it together, 50-50 by weight or volume, press it over what you want, and it's ready to use in about 15 minutes. You can use only what you need. One pound--a lot of the stuff--is $30 at Hobby Lobby but I've used the 40% off coupon on two boxes of it, which should last me a LONG time. MUCH easier to use than measuring and mixing liquids, and building up dams to pour them, and so forth. Great stuff! Quote Link to comment Share on other sites More sharing options...
sbk Posted June 30, 2018 Share Posted June 30, 2018 (edited) Polytek Plat-Sil 71-11 silicone & 1512X resin is what I have been using for years. Mold making & casting in a 2 gal. pressure tank, no vacuum or mold release needed. The resin is white, color differences are due to the lighting in the photo. Resin copy of a scratchbuilt 1949-1950 Merc. door handle fresh from the mold. The aqua colored thing is the mold. After a little cleanup. Resin copies of scratchbuilt 1949-1950 Ford interior parts. After black enamel & Alclad II chrome. Resin copies of scratchbuilt flipper hubcaps & 1935 Olds side hood trim. Castings come out as smooth & glossy as the patterns are. Steve Edited June 30, 2018 by sbk Quote Link to comment Share on other sites More sharing options...
Ace-Garageguy Posted June 30, 2018 Share Posted June 30, 2018 21 minutes ago, sbk said: Polytek Plat-Sil 7 1-11 silicone & 1512X resin is what I have been using for years. Mold making & casting in a 2 gal. pressure tank, no vacuum or mold release needed. The resin is white, color differences are due to the lighting in the photo. After black enamel & Alclad II chrome. Ah yes. THIS is the kind of quality to strive for. Beautiful work, Steve. Did you make the masters as well? Quote Link to comment Share on other sites More sharing options...
sbk Posted June 30, 2018 Share Posted June 30, 2018 Thanks....it's been a long day. I've been editing this post for the past 15 minutes or so. Hopefully, the version I saved is correct. Yes, I did the masters on all of these. Quote Link to comment Share on other sites More sharing options...
Art Anderson Posted July 5, 2018 Share Posted July 5, 2018 On 6/25/2018 at 6:26 PM, Chariots of Fire said: Micro-Mark sells 50:50 two part mold making RTV. it is easy to mix and sets up well in about 4 hours. Not cheap but you can get quite a few nice molds from one package. If you do two part molds you would need to purchase some mold release agent as well. Mold release for making two-piece molds is as close as your medicine cabinet--for over a decade of commercially casting in resin, making 2-part RTV rubber molds, the most foolproof mold-making barrier, and the cheapest, which I used exclusively. ordinary Vaseline Petroleum Jelly, which I added to a 4-oz bottle of ordinary enamel thinner, to make my own mold-release in order to keep the second pour (the inner core of a mold) from adhering to the first (cavity side of the mold) pour. Worked without fail every time. Art Quote Link to comment Share on other sites More sharing options...
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