JRammit Posted September 30, 2015 Report Share Posted September 30, 2015 I thought i solved this problem once i started baking my plaster molds... But it happened again Does anyone else get mold on their mold??... Im talking the stinky green kind, like on that plate in the sink you forgot to wash for a week My molds are plaster, baked at 170 for 20 minutes and sealed with elmers 50/50... I store the molds closed (face to face), most of them are fine, but occasionslly i open one up and find black spots and pinkish/green fuzz on them My guess, its from the PAM cooking spray i use when shooting them... But how do i stop it??... Cant exactly wash plaster in soapy water....... Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted September 30, 2015 Report Share Posted September 30, 2015 Possibly still some moisture in the mold. Open and well ventilated I would say. If I had a lot of molds to store, I would be building a cabinet with a computer extractor fan in the bottom, to keep the air moving and pulling fresh air through continuously. These fans are low power and safe to run continuously. Or if you are concerned, a timer or switch on and off with you workshop lights. This would be enough ventilation to keep the molds clean. Dave Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 30, 2015 Author Report Share Posted September 30, 2015 This is a good answer, as i read it i realized i only have this problem with newly made molds... Many of my older molds have been stored in the same way and do not have this issue Still, i thought the sealer would prevent this... Simple solution never the less, thanks Dave Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted September 30, 2015 Report Share Posted September 30, 2015 (edited) Actually, the sealer makes it worse, by preventing the moisture from escaping so easily. But, we need a seal coat, but don't be tempted to seal all over, otherwise you will lock any moisture in. Not really practical, but a cabinet in the warmest part of the house would be perfect. Here in Indonesia, temperature is not an issue, but humidity is high. I have had to throw out a pair of leather shoes that I had not worn for a year, also a leather jacket needs rescuing. These items were just laying on a clean, tiled floor, undisturbed. So when I start making molds, I will definitely be taking my own advice. Even the occasional extra half a day in the lamp heated drying box. In fact, when I start building again, I will design the storage cabinet and drying box as one unit. Dave Edited September 30, 2015 by Vodkaman 1 Quote Link to comment Share on other sites More sharing options...
mark poulson Posted September 30, 2015 Report Share Posted September 30, 2015 (edited) When I made my first pop molds, I had that problem. For me, it was because I wasn't waiting long enough for the pop to truly dry before I sealed it. I was in a hurry. Surprise, surprise! As Dave said, moisture that is still in the pop before sealing is trapped by the sealer, so it's important to make sure the pop is really dry before sealing. This is the first time the automatic translation to pop has helped me, since I type for crap. Edited September 30, 2015 by mark poulson 2 Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 30, 2015 Author Report Share Posted September 30, 2015 I never seal the back of the mold, only the face Drying was easy when i was making small single cavity molds.... But now that im making larger multi cavities, its becoming an issue..... The dry box is a great idea... Ill come up something similar for the next mold Quote Link to comment Share on other sites More sharing options...
mark poulson Posted September 30, 2015 Report Share Posted September 30, 2015 Maybe I have more trouble drying my pop molds because I always make shallow plywood boxed for them, so they are more protected from my clumsiness. Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 30, 2015 Author Report Share Posted September 30, 2015 Mark, i tried your plywood box, all i made was a mess (ha ha!)... I couldnt stop the leaking out when i flipped the box, so the top of the molds ended up hollow Since then, ive just made 3x thick molds, havnt cracked one yet (but i havnt dropped one either), likely why they are taking so long to dry Did have an idea though, just havnt tried it...... Wonder if applying a rubberized coating to the outside of the mold (once completely dry) would protect it from "fumbles"??.... The spray on "flex seal" from that infomercial comes to mind...??? Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted September 30, 2015 Report Share Posted September 30, 2015 Funny you should mention this. Just yesterday I found a coffee cup on a shelf in the shop... 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted September 30, 2015 Report Share Posted September 30, 2015 Mark - your molds are very professional, I really like your method. However, my method is going down a different road, which I will be ready to post in a month or so. I cannot encase the molds, but they will have ply backing plates to spread the clamping loads. Dave 1 Quote Link to comment Share on other sites More sharing options...
alsworms Posted September 30, 2015 Report Share Posted September 30, 2015 Funny you should mention this. Just yesterday I found a coffee cup on a shelf in the shop... Ha! It's amazing what you can find out there, right? In my case, it was usually a half empty beer or 2. As for the mold, this is news to me. I made hundreds of plaster molds and never had the problem. Had plenty of OTHER problems, but mold wasn't one of them. lol Quote Link to comment Share on other sites More sharing options...
mark poulson Posted September 30, 2015 Report Share Posted September 30, 2015 JR, My experience with pop is that it doesn't like to be dropped, no matter how thick. I actually line my plywood boxes with fiberglass drywall mesh tape, to give it some reinforcement. That way, I can get away with thinner molds with them being too fragile, but my boxes are the major reinforcement. I always coat the box with some sort of spray-on clear, so the water from the pop doesn't reach the box before the pop dries. I still haven't mastered laying my soft plastic masters onto the open face of the pop mold without having an irregular face when I'm done. I know the smart way is to glue the masters to a flat surface, glue my 1X frame around them with hot glue, and then fill the frame up with pop. Once it's full it's a matter of laying in the mesh, and then pushing the plywood back down onto the wet pop, forcing the excess out of the sides, and then attaching the plywood. But that is a method I haven't tried, yet. Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted September 30, 2015 Report Share Posted September 30, 2015 Mark - your molds are very professional, I really like your method. However, my method is going down a different road, which I will be ready to post in a month or so. I cannot encase the molds, but they will have ply backing plates to spread the clamping loads. Dave A load spreader on the back makes sense, but I've wondered why not also install load points in plaster molds. This should reduce or eliminate compressive damage on two piece plaster molds. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted September 30, 2015 Report Share Posted September 30, 2015 (edited) I fill my second half of my two piece molds full of pop, , brush some pop onto the exposed masters, lay the first half face down onto the second half, squeeze out the excess pop, and then turn the two halves over, so the wet half is on top. Then I tap the wet half box with a rubber screwdriver handle to help the pop settle down around the masters, and to help any trapped air to rise up away from the masters. So far, I haven't had any problems, when I use small bar clamps, under just enough pressure to hold the halves together, while I pour or inject. Maybe it's because the meeting faces are mirror images of each other when I use this method. Edited September 30, 2015 by mark poulson Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 30, 2015 Author Report Share Posted September 30, 2015 (edited) Mark, I use to lay my masters in wet plaster and pour over them.. It worked, got many molds this way..... But, when making a multi cavity, the clock is ticking against me trying to carefully/quickly lay in all the pieces before the plaster hardens...... So, im switching to the clay bed method.. More tedious, but also infinite working time... Edited September 30, 2015 by JRammit 2 Quote Link to comment Share on other sites More sharing options...
RayburnGuy Posted September 30, 2015 Report Share Posted September 30, 2015 As far as the mold, have you tried laying them in the sun to get rid of the mold? UV light kills all sorts of "lil nasties". Ben Quote Link to comment Share on other sites More sharing options...
Slammingjack Posted September 30, 2015 Report Share Posted September 30, 2015 I stopped using pop a long time ago. I use D.W.P. , I just like the way the mold comes out. Did get mold on the bottom of one. I think it was the way I let it dry. I let mine dry for a week before before I seal it. The mold was thick and I never turned it over. Must have been moisture on the bottom. Never did seal the bottom but there is still black spots on the bottom. That was over a year ago. Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 30, 2015 Author Report Share Posted September 30, 2015 I stopped using pop a long time ago. I use D.W.P. , I just like the way the mold comes out. Did get mold on the bottom of one. I think it was the way I let it dry. I let mine dry for a week before before I seal it. The mold was thick and I never turned it over. Must have been moisture on the bottom. Never did seal the bottom but there is still black spots on the bottom. That was over a year ago. I went the opposite way... Ive only used DWP (the moldy mold is DWP) but im tired of the bubbles (and the price) so im switching to POP Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 30, 2015 Author Report Share Posted September 30, 2015 As far as the mold, have you tried laying them in the sun to get rid of the mold? UV light kills all sorts of "lil nasties". Ben Good idea, i will try this right now! Quote Link to comment Share on other sites More sharing options...
Travis Posted September 30, 2015 Report Share Posted September 30, 2015 (edited) Simply let the mold dry. Honestly we screw ourselves over so much in our rush to make baits, wonder wait percentage of posts on this site boil down to nothing more than guys rushing/taking short cuts, etc.... Any sort of special drying, storage, etc.. is simply not needed, just creating solutions to non problems. I did have mold the first few molds (12 years ago or so) since then several hundred molds and zero issues. I just let them dry a few days before storage. I will seal and pour baits the following day (mold still wet) and just leave out on a drying rack before actual storage. I also don't use Elmer's as just adding water back to the mold. Devcon thinned gives better results in my opinion. I don't use POP as much anymore and prefer DWP. If you have bubbles I have to say it is user error.. I use a very complicated method...dump into bowl add water mix. then knock the bowl a few times. Then I hit the bubbles with air (through straw), air brush, or quick pass with torch to bust then mold. As far as cleaning up the mold, I have a few still with the mold stains that I use but chucked the others. Edited September 30, 2015 by Travis 2 Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 30, 2015 Author Report Share Posted September 30, 2015 Ive used pretty much the same mixing procedure (except for the torch part), some molds come out fine, some are full of air bubbles i have to go back and fill.... I don't really do anything differently Thing is, currently im making several rather large molds.. Since they are for testing a new method, many of them are scrap... I can only buy DWP in a 4lb can, and ive already cleared the shelf at Lowes... So i opted for the 25lb bag of POP, cant decide weather i like it or not??? Quote Link to comment Share on other sites More sharing options...
Travis Posted October 1, 2015 Report Share Posted October 1, 2015 (edited) I don't mess with the torch now just used it several times based on some accounts of it working well. I will try about anything to see if it improves something just find majority of the time just unnecessary. Knocking the bubbles out works the majority of time. Few times there are bubbles filled afterwards with thicker mix (puddy) and rubbed smooth. This may be 2 or 3 pin head sized bubbles. I can understand using POP to work things out for sure. Most of the POP I used made very good molds but DWP just seamed to pick up detail much better and overall seamed to make better quality molds (especially 2 piece as they held up a lot better along face joint/cavity points). Edited October 1, 2015 by Travis Quote Link to comment Share on other sites More sharing options...
mark poulson Posted October 1, 2015 Report Share Posted October 1, 2015 Travis, What you said about switching from Elmer's glue to thinned D2T rang a bell for me. I did the same thing, years ago, and haven't had any more mold issues. Quote Link to comment Share on other sites More sharing options...
JRammit Posted October 1, 2015 Author Report Share Posted October 1, 2015 I like the idea, but im stingy with my D2T since i have to order through mail when i run out (which i have)..... Elmers i can pick up from the ol Walmart on my way home from work Silly question though.. What keeps the epoxy from running down and pooling up in the cavity??... Surely you dont put the mold on a lure turner......?? Quote Link to comment Share on other sites More sharing options...
Travis Posted October 1, 2015 Report Share Posted October 1, 2015 I thin to water consistency and start layering. It soaks into the mold for the first several coats. I keep building until I get a smooth finish. It leaves a very thin layer each time and doesn't really run (putting it on too heavy if that is the case). If it does run, it is like water and you just tilt the mold to the desired area or brush it out. 1 Quote Link to comment Share on other sites More sharing options...
