Rippinlips26 Posted February 20, 2017 Report Share Posted February 20, 2017 I been making my prototype baits out of clay. Bake on 350 for 8 mins. But I can never get the bait out of the plaster without breaking it. Is there a trick? Please help lol Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted February 20, 2017 Report Share Posted February 20, 2017 (edited) Ideally silicone would be the best choice for the mold material. You can then cast several sub-masters from plastic and make multi cavity plaster molds. Dave Edited February 20, 2017 by Vodkaman Quote Link to comment Share on other sites More sharing options...
SW Lures Posted February 20, 2017 Report Share Posted February 20, 2017 There are releasing agents, but for POP I'm not sure. I believe JR has used something for a releasing agent. You state Rip, that you are making them (baits) out of clay or are you referring to Plaster of Paris (POP) for the mold? Dale Quote Link to comment Share on other sites More sharing options...
Rippinlips26 Posted February 20, 2017 Author Report Share Posted February 20, 2017 Yes the plaster of Paris is my mold. I'm using the clay to make the print Quote Link to comment Share on other sites More sharing options...
Travis Posted February 20, 2017 Report Share Posted February 20, 2017 If the master is designed in a fashion that it gets locked into a rigid mold it will get locked and result in the master needing to be destroyed. I stopped baking clay a long time ago as just easier to remove if using it for a master and you end up destroying the master anyway. Usually a release agent isn't critical but won't hurt. Johnson's Paste Wax, Vasoline, or a commercially designed release agent can help (I use Mann Ease Release). Another useful trick for hard masters, if thick enough, is drill a hole and carefully screw in a wood screw. That way when you bake your clay you can then insert the screw and have a handle to pry/lift the master out with. I mainly use this technique on wood masters but have used it on clay. Switch to RTV as mentioned and doesn't become an issue. You can can also use bondo body filler to make the mold and demold once just set up. The mold will have some give to it and you can at time extract the master easier. Bondo boy filler molds aren't as robust as other molds but can make some decent molds for limited casting. Especially if just to make soft plastic masters. 1 Quote Link to comment Share on other sites More sharing options...
Landry Posted February 20, 2017 Report Share Posted February 20, 2017 Interesting topic. I am planning on making two part molds of POP using wooden masters with no undercuts. Will these come out alive??? i want to use the masters again for silicon mold. Just was hoping to check how baits run using POP first. Quote Link to comment Share on other sites More sharing options...
Travis Posted February 20, 2017 Report Share Posted February 20, 2017 If no undercuts should be fine. For a wooden master another important aspect is seal/sand that master very well. A minimal of 220 grit. I use shellac to seal/sand to get a very smooth surface and use a very thin coat of mold release. Quote Link to comment Share on other sites More sharing options...
Landry Posted February 21, 2017 Report Share Posted February 21, 2017 My masters are glass smooth with envirotex coating. I will do one first and see if it survives. Will use a liberal coat of Vaseline since it is just a tester mold. Quote Link to comment Share on other sites More sharing options...
Rippinlips26 Posted February 21, 2017 Author Report Share Posted February 21, 2017 How do.you make a master out of silicone? Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted February 21, 2017 Report Share Posted February 21, 2017 4 hours ago, Rippinlips26 said: How do.you make a master out of silicone? The original master is made of wood or clay, something hard that will hold its shape. The mold is made of silicone so that the master can be retrieved and stored. Resin sub-masters can then be poured and used to make a multi-cavity mold either in silicone or PoP. A resin sub-master is easier to extract from a PoP mold, but even if it breaks you can make more. Dave 1 Quote Link to comment Share on other sites More sharing options...
uttexas Posted February 21, 2017 Report Share Posted February 21, 2017 The softer the fully cured mold making material, the easier it is to get a rigid clay, wood, or epoxy master prototype out of the mold. Anything harder than 34 tear strength silicone and you will have significant issues getting a rigid master out of the mold. POP works great for soft plastic prototypes. One possible solution that I've never tried-- Dip your rigid clay, wood, or epoxy master prototype in some clear hot plastic. Let it cool. Repeat a time or two. Then try a POP mold. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted February 21, 2017 Report Share Posted February 21, 2017 The rule of thumb I learned here on TU is hard master/soft mold, and soft master/hard mold. Mold making silicone is the best thing to use with a hard master. But it is relatively expensive. If you go on Larry Dahlberg's website he has a video on how to do it. If you're cheap, like me, you can make a silicone mold for a hard master with the 100% silicone that comes in caulking gun tubes, and then make a dozen baits with hard plastisol to use as masters for your POP mold. This way takes a lot more time than with the mold making silicone. If I had money to spare, I'd use Larry's mold making silicone every time I needed a mold. The 100% caulking gun silicone is hard enough to hold it's shape, but soft enough to let you use a hard master if it's well sealed and smooth, even with reliefs and undercuts. That way, you don't need a lot of expensive silicone mold material. A tube of silicone is like $5+-. If you coat your master with a thin layer, applied with your finger so it gets into all the recesses and details, you can surround that with more silicone that has a couple of drops of water mixed in it, and the silicone will set much more quickly. When you're done, your master will be completely encased in silicone, and you'll have to cut it out once the silicone is set. You should still wait 24 hours before you cut down to the master and remove it, but you'll get a good mold. I make an open top mold box when I do that, and can slip the mold back into the box once it's filled with plastisol to hold it's shape. If you make them with hard plastisol, and coat them with spray PAM before you embed them in the POP, they should last a while. And keep the silicone mold so you can make more soft masters, if you need more. 1 Quote Link to comment Share on other sites More sharing options...
Rippinlips26 Posted February 22, 2017 Author Report Share Posted February 22, 2017 Mark thanks for the information yes I am cheap lol. Texas I will have to try that. I poured some today just need more detail. Ill get it figured out thank yall 1 Quote Link to comment Share on other sites More sharing options...
