northsea Posted November 23, 2008 Report Share Posted November 23, 2008 I'm having bother trying to get my POP molds free from air bubbles just at the tails of my lure. The rest of the mold is is totally bubble free and always try to vibrate all the bubbles out after pouring. I stick my lures to the pan then pour on top. I've tried brushing the plaster on initially then pouring but still get problems with 2 or 3 small bubbles at the edge of the tails. I get no bubbles anywhere else. Can anyone help me please? Should I try and make a much thinner mix of plaster and only pour at one corner and just keep pouring there? I can't seem to get my plaster runny enough and wonder if mixing the plaster too much could cause this? The reason I try and mix as much as possible is because lumps are a complete pain and desperately want to get them out. Any tips on mixing and pouring would be excellent! Quote Link to comment Share on other sites More sharing options...
Zbass Posted November 23, 2008 Report Share Posted November 23, 2008 It sounds like you are on the right track. The only thing I might suggest is to let the plaster flow towards your master and that way it shouldn't have bubbles. Painting the bait with plaster first is a huge help. You may try to leave extra around the edges when you do this. Hope this helps. Zbass Quote Link to comment Share on other sites More sharing options...
Basseducer Posted November 24, 2008 Report Share Posted November 24, 2008 You could also use a flour sifter to break up any lumps brfore you mix and put in a little at a time. Just a thought. Quote Link to comment Share on other sites More sharing options...
northsea Posted November 24, 2008 Author Report Share Posted November 24, 2008 Thank you guys for the suggestions! I had another go yesterday brushing the plaster on carefuly but noticed there were tiny air bubbles in the plaster I was brushing!!! I did try the stir carefully but I guess this is most likely the problem I am having. Has anyone had this happen? Any tips on mixing plaster to avoid this? Any help much appreciated! Quote Link to comment Share on other sites More sharing options...
nova Posted November 24, 2008 Report Share Posted November 24, 2008 Question: What is the master made of? Is it wood and if so, did you seal it before you put it in the pop? www.novalures.com Quote Link to comment Share on other sites More sharing options...
northsea Posted November 24, 2008 Author Report Share Posted November 24, 2008 Master is a rubber lure and I am sticking it to a pan then pouring the plaster on top after painting some plaster on. I still feel the problem is in the plaster itself having very, very small bubbles in it. Is there a good way to get rid of them before brushingthe lure with plaster? Quote Link to comment Share on other sites More sharing options...
nova Posted November 24, 2008 Report Share Posted November 24, 2008 The bubbles could be coming from the plaster itself or they could be coming from under the bait. If you are mixing the plaster to quickly (whipping) you are putting small air bubbles in the mix and as the plaster settles these bubbles will come together to make larger bubbles. Try mixing the plaster more slowly. When you glue the bait down make sure it is completly sealed with no air pockets under it. Some of the guys are using double-faced tape. I have not tried this but it sounds like it may be very good. www.novalures.com Quote Link to comment Share on other sites More sharing options...
northsea Posted November 24, 2008 Author Report Share Posted November 24, 2008 Thank you for the suggestion there I will have a go at mixing slower as I think this could be the problem. I actually have been using double sided tape and it seems to improve things much better. One last point about mixing plaster is the was you mix it. Do you simply use a wooden spoon or something? Also do you stir the mixture as you add the plaster to the water? The instructions tell me to add plaster to water then leave to soak for a minute or two but I find it impossible to get all the plater in the measured water no matter how gradually I do things. Quote Link to comment Share on other sites More sharing options...
nova Posted November 24, 2008 Report Share Posted November 24, 2008 I never use wood to stir anything. I use metal or plastic. Actually, I've seen POP mixed using your hands on a TV program once. It's probably the best way but it's quite messy. (maybe with rubber gloves it would be easier on the hands). I'll be working on new designs soon and I'll give it a try. www.novalures.com Quote Link to comment Share on other sites More sharing options...
21xdc Posted November 24, 2008 Report Share Posted November 24, 2008 Mix the plaster thicker at first. This will beat the lumps out. Then thin it to your desired consistancy. I am a drywall finisher and this is what we do with any powder mud. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted November 25, 2008 Report Share Posted November 25, 2008 (edited) The way I mix mine, is to put the water in a plastic container with round corners, like an ice cream container. I sprinkle the plaster into the water, through my fingers, slowly. Once all the plaster is added, I then stir with my fingers, Slowly, dealing with any lumps as I go. I find this method minimises both the lumps and the air bubbles. I give the container plenty of tapping and give the bubbles a minute or so to rise. Pour in one spot and allow the plaster to flow to your master, do not pour onto the master, this will trap air in the corners between the master and base. I also paint the plaster onto the master with a soft brush, making sure I get into all the corners. This wets the surface and makes it more difficult for the bubbles to adhere. You still have to tap the mold after pouring though. The above method of mixing I found by googling the web. Try a google yourself, lot of good info out there. I think Nova is on the money though, with trapped air under the tail. Dave Edited November 25, 2008 by Vodkaman Quote Link to comment Share on other sites More sharing options...
northsea Posted November 25, 2008 Author Report Share Posted November 25, 2008 Many, many thanks indeed everyone for all this sound advice!!! I'll have a go with my hands and see what happens then brush round the corners and pour the plaster away from the master. I'll let you know how it goes. Quote Link to comment Share on other sites More sharing options...
MONKEYqpHUNTER Posted November 26, 2008 Report Share Posted November 26, 2008 i use a metal whisp for baking to mix my plaster it takes care of the lumps and being made of small round wire there are no flat sides like on a spoon to trap air between when stirring.ty it they are a dollar at the dollar store. Quote Link to comment Share on other sites More sharing options...
RiverMan Posted November 27, 2008 Report Share Posted November 27, 2008 (edited) After you mix the plaster, tap the container on the counter and pop the bubbles with a hair dryer. Tap again and pop the air bubbles again. Slowly pour the plaster as others have described and then tap the container to lift the bubbles away from the part. If your master part is made from wood you will need to seal it first. jed Edited November 27, 2008 by RiverMan Quote Link to comment Share on other sites More sharing options...
northsea Posted November 27, 2008 Author Report Share Posted November 27, 2008 Interesting points added there! I like the idea of the hairdrier but not sure what the misses will say about it all. I had a go lastnight mixing the plaster with my hands. Man that was messy. Although the mould turned out better there were still a number of tiny bubbles in the plaster mix. I take it that the plaster I use to brush on the master should be completely bubble free or it will defeat the purpose of brushing. Perhaps the hair drier idea could help here. I wonder also if I am getting the plaster thickness right. I tend to get it to the stage where it just runs off the spoon(hand) Also when brushing on the plaster I get a good amount on the brush and work it around the tails instead of brushing the plaster on top of it. Perhaps the mixture it slightly too thick because the plaster never drips off the brush no matter how much I have on it. Any further feedback would be brilliant! Quote Link to comment Share on other sites More sharing options...
Trapper Don Posted November 27, 2008 Report Share Posted November 27, 2008 I made a 4 bay mold maker (we make a lot of molds) and pour a lot of plaster. If you mix your POP thin, your working time is longer, your air bubbles come up easier and... if you put a vibrating orbital sander underneath the mold your bubble problems are gone. (99.9%) But that works with our setup because its heavy. If you are making them one at a time the mold may be too light and bounce around on top of the sander. Im sure it could be modified. Quote Link to comment Share on other sites More sharing options...
Joe S. Posted November 30, 2008 Report Share Posted November 30, 2008 If the bubbles are tiny and minimal, I wouldn't worry to much about it as they will most likely fill in when you seal it;) Quote Link to comment Share on other sites More sharing options...
