ckarren Posted September 9, 2004 Report Share Posted September 9, 2004 I would love to know what I am doing wrong when I make plaster molds. I made one this weekend that did not turn out. Everyone that I have made I can?t get the template out off the mold. I have tried every thing to lube it up. I even tried taking it out when it has not setup all the way and it will take some of the plaster with it. Thanks -Corey Quote Link to comment Share on other sites More sharing options...
woodsac Posted September 9, 2004 Report Share Posted September 9, 2004 Corey, First off what is your master made of, wood, plastic, metal? What have you tried so far for release agents? Next, give us a step by step on how you're doing the mold. Quote Link to comment Share on other sites More sharing options...
ckarren Posted September 9, 2004 Author Report Share Posted September 9, 2004 I have used KY jelly, Vaseline, Pam cooking spray and vegetable oil I was going to try gear lube. The master is made of, wood. I make the master copy lube it up and put it in the bottom of a Rubbermaid container. Spray Pam spray allover everything. Mix the plaster I start with a spoon so everything is getting a coat. When the master is hidden under the plaster I will pore the rest of the mixed plaster. Thanks for your help. -Corey Quote Link to comment Share on other sites More sharing options...
redg8r Posted September 9, 2004 Report Share Posted September 9, 2004 The master is made of, wood. Have you sealed the pores in the wood? Like a gloss acrylic paint or thinned epoxy? That helps alot, also, rather than using those types of lubricants, try a little dishwashing liquid brushed lightly over the master. Some lubricants like what youve mentioned will prevent the plaster from curing properly around the master. While were on this topic, I seen a guy use a nifty trick to help remove air bubbles from his molds. He took a jigsaw & removed the blade, then clamped the jigsaw to his worksurface & ran it a few minutes after pouring the mold. the vibration helps work the bubbles up & out of the plaster. Ive banged my head coming up with all these exotic ways of making a vibration table & didnt realize it could be that easy good luck Quote Link to comment Share on other sites More sharing options...
ckarren Posted September 9, 2004 Author Report Share Posted September 9, 2004 Thanks Red I don?t think it is preventing the plaster from curing properly around the master. When I try to remove the master it don?t wont to come out. Then I force it out and the mold will crack come a part and crumble. I have not coated the wood with any thing other then what I said. Thanks -Corey Quote Link to comment Share on other sites More sharing options...
redg8r Posted September 9, 2004 Report Share Posted September 9, 2004 I have not coated the wood with any thing other then what I said. Yeah, Id clean up the wood & give it nice glossy topcoat. thatll seal the wood & help prevent the wood from bonding with the plaster. I know its frustrating, everyone including me gets impatient & wants to demold asap to see how it turned out. unfortunately plaster is one of those materials that takes a few days to fully harden & will be real fragile until then. Quote Link to comment Share on other sites More sharing options...
willgohome Posted September 10, 2004 Report Share Posted September 10, 2004 ckarren I too am new at this but by using Durham's water putty and Pam canola oil spray as a release agent I've had pretty good results so far. Mine is a 2 part mold for a striped bass lure and one thing I learned to watch out for is undercuts as I use a modified hard plastic lure and there is no give like you would have with a soft lure as a master. When I complete this 2 part mold I will cast about 6 softies so that I can use them for a one part mold to produce 6 at a time. By using the softies for the multiple mold I hopefully will be able to remove them in an almost round shape. We shall see. Try the Durham's, it works pretty good. J Will J Quote Link to comment Share on other sites More sharing options...
ckarren Posted September 10, 2004 Author Report Share Posted September 10, 2004 Thanks Will and Red. Will how big is the lures that you are doing for the striped bass. I am trying to make a muskie lure that is about 8? with out the tail and about 2? wide this is a big lure. Red now that you brought it up I think, no I know you?re correct. I think the wood is sucking in my entire release agent and the plaster is sticking to the lure. Like I said thanks for all the help! I bet I have gone through about 5 or 6 boxes of plaster without a good mold. Thanks -Corey Quote Link to comment Share on other sites More sharing options...
the_hide Posted September 10, 2004 Report Share Posted September 10, 2004 If you have a hard master like wood , fimo etc. I always make my original single cavity mold out of RVT, pour a couple of good quality copies out of the RVT master and then use those baits to make multi cavity plaster molds. I would have thought that a devcon coated wood master would pull out of plaster ok. When I drop my masters into the plaster they are actually glued to devcon coated plaster pour and/or injection hole inserts so I don't have to cut this stuff out the mold later. These inserts allways pull out clean so I guess the devcon coated wood should too. Im not sure if you guys use simple plaster of paris but I've been using some of the US Gypmsum companies Hydrastone its sets like a rock literally, this stuff can be slow cooked in the oven or microwave and the mold can be ready for sealing the same day you create it. Quote Link to comment Share on other sites More sharing options...
