Hi to all on this great forum. I just joined and also just starting in gathering as much info I can about forms and casting. I have practiced with plaster of plaster and homemade silicone caulk mixtures with some success. But no where near what i am looking for. I understand money is pretty much what will be needed to get the best products and results I want. I will just explain what I am trying to accomplish and hope for some great input. I have four plastic logos like the one pictured on my camper trailer I want to mold. I have some repair to do on this one, but it will be used as the molding item. The form box will be made of plastic and is no problem. The logo measures 22' long,3' tall and 1/8' thick. I am confident I can make a mold from plaster of paris. AND it is the least expensive by far. Is this they way I should go to make four copies? Is a commercial silicone the best and most economical to use for a limited number of copies? The biggest area I need advice on is the material to use to pore the mold. I am no chemist and try to read and understand what is available, but have found no material that can be used exclusively out doors. Any help will be greatly appreciated. c
Ideally would you want the logos to be a hard cast plastic? Do you want it the same color as shown in the picture or do you plan to dye the cast or simply paint the cast pieces when they come out of the mold?
My recommendation would be to use High Strength 2 silicone mold making rubber to make your mold and AlumiRes RC-3 to cast the pieces.
Making a mold out of plaster limits what you can pour the pieces out of. It is very difficult to remove rigid cast pieces from a rigid mold. Something has to give and will either damage the mold or your cast pieces during demold. The High Strength 2 silicone mold making rubber will not effect your masters, give you a perfect mold with all the detail of your original, and allow you to pour practically any casting material into it over and over again.
Your mold box sounds perfect. Just make sure your logos are fastened down to the mold base to avoid any High Strength 2 from creeping under it and eliminating the chance of the logos floating.
Hi Mike. Thank you so much for the info. Very helpful. Yes I wanted to cast with plastic. Not being sure if cast plastic could withstand the outdoors I had planned on painting the pieces. I have painted other plastic pieces already so this would allow me consistency with all of them. My experimenting proves your comment on hard items cast (JB Weld for one)in a rigid being very difficult to extract. The back of the emblems are flat so I use two sided carpet tape to secure them. Almost too good! I used corrugated plastic yard signs to make the box sides and a flat work surface. I will calculate how much material and get started. Thank you again very much.
What do I use to make something that I want to be flexible AFTER it comes out of the mold? I want to make a mold of my action figures and then make new ones that can bend, which I can then use for stop motion videos. Any suggestions?
I would recommend either Flex 60, 70, or 80. The lower the number, the softer. You may need to dye the resin as painting flexible resins is fairly tough to get good paint adhesion. Design Master has a spray paint that bonds exceptionally well to our Flex Series rubbers.
I had a favorite pair of earrings, an elongated Celtic knot - I lost one as there is little chance of getting back to Ireland to find a replacement I would like to make a mold I can use to duplicate it in precious metal clay. I assume I’m going to need something flexible enough to get the original out once molded, but firm enough to press the clay into. Any advise would be appreciated.
DinahH, are the earring a metal material or is it made from the precious metal clay? Either one, I would use either High Strength 2 or 3 as a mold material. If it's metal then either one will not hurt your original but if it's made from clay then go with 3 as it's a "softer", less stiff material and will be easier to remove the original from. Both are flexible but 2 is stiffer - think rubber stamp stiff. A liquid mold material will be the way to go to get the most detailing. Just be sure to have the edges of the earring sealed where it lays on the mold box so that the liquid doesn't get under the earring cause if there is the smallest crack in the under edge, the liquid WILL get under it and you will have to take a pair of scissors to carefully snip the mold material off to get the earring out. I use a tiny pair of sewing scissors to clean up any extra mold material that gets where I don't want it. Hope that helps.
Hi I had purchased the amazing casting resin by moldputty. I'm having a hard time making the mold of the piece I'm trying to cast and I don't think it's gonna come out good. But my question is can the casting resin be poured into a plastic bottle? The piece I'm casting is a skull shaped soap despencer and I figured it would b super easy to just pour it in that then just break it open to remove the cast. If not any suggestions please. Thank u.
kimmi1234, I wouldn't pour the resin directly into a plastic bottle - the resin gets pretty hot and plastic will usually give off an "odor" when it melts (might be toxic too) and it will most probably melt due to the heat of the resin. Plus to break it open there is a chance you will scratch or even break pieces of the resin itself. You might need to make a two piece mold of the skull, is the resin skull going to be solid or do you need it hollowed out? For something that you need in a rounded shape (meaning the flat side is underneath the skull) I'd use one of the liquid mold rubbers. The liquid mold rubber will get in all the nooks and crannies you want it to and pick up every detail with ease. The only thing is you need to pour it slow and be careful of the bubbles and it takes 18-24 hours to set (most of them do) but it's worth the time taken. Plus none of the mold materials get hot so your original skull won't get ruined. You might want to do a two piece mold or one piece with a "cut line" halfway down the sides kind of mold. We can guide you on making either one if you need it.
Post by carol - Alumilite Corp on Aug 22, 2018 15:11:28 GMT -5
Notoes is correct. It could soften the plastic maybe not melt it and the likelihood of it sticking to the bottle is another possibility. If the skull has a flat side (perhaps post a picture) you may be able to do a one piece mold using one of the softer silicone's HS3 or the Plat 10/25. The very least odds are you could do a mold and put a split up the side so you wouldn't have as much flash to clean off as you would a two piece mold. We made some great skulls here for Halloween last year and there are people who make gear shit knobs skull shaped with the HS3 great results, picture will help. Truly a picture is worth a thousand words Kimmi there is a wealth of knowledge lurking and ready to answer in this forum.