FatFace Fishing Lures Posted March 29, 2015 Report Share Posted March 29, 2015 Hi everyone, I am having some issues with bubbles on my swimbaits and I need some help getting rid of them. I will start off by explaining what I am doing. I make my own lures by hand and make my own silicone molds as well. I melt my plastic in a pan and pour it between 340 and 350 degrees, but i've tried all different temperatures and none of them fix my problem. My lures swim awesome and I know the fish don't care if they are smooth or not, but I would just like to know how to make them smooth like my mold. There is not water nor moisture in the mold, which leads me to believe that there is just air being trapped inside of the cavities. Here is one of my molds These are the finished swimbaits If you look closer, you can see the bubbles If you know how to fix my bubble problem I would love to hear it, any input is greatly appreciated. Thank you Quote Link to comment Share on other sites More sharing options...
Painter1 Posted March 30, 2015 Report Share Posted March 30, 2015 Bubble are common when the plastic is heated quickly in a microwave. Different power levels on ovens can produce the result worse than others. Not the only reason for bubbles, but I struggled with it myself. I turned down the power and heated in increments. Some brands of plastic are worse for this than others. 1 Quote Link to comment Share on other sites More sharing options...
camrynekai Posted March 30, 2015 Report Share Posted March 30, 2015 It looks like degassing of the silicone. Is the silicone you used meant for Hi-temp use? Have to be very careful with what type of silicone that you use for pouring 320 degree plastic into....some/most silicones give off large amounts of formaldehyde gas when heated...causing the bubbles to form on the contact surface as seen in your photo's. This problem you show can also happen with the first few uses of the newly made mold, especially if your using molding silicone....it contains a small amount of release agent that will burn off with use. Quote Link to comment Share on other sites More sharing options...
FatFace Fishing Lures Posted March 30, 2015 Author Report Share Posted March 30, 2015 Bubble are common when the plastic is heated quickly in a microwave. Different power levels on ovens can produce the result worse than others. Not the only reason for bubbles, but I struggled with it myself. I turned down the power and heated in increments. Some brands of plastic are worse for this than others. I cook my plastic in a pot on a hot plate and usually I just put it on high because it is faster. Do you think I should put it on medium and let it cook a little longer? Thanks Quote Link to comment Share on other sites More sharing options...
FatFace Fishing Lures Posted March 30, 2015 Author Report Share Posted March 30, 2015 It looks like degassing of the silicone. Is the silicone you used meant for Hi-temp use? Have to be very careful with what type of silicone that you use for pouring 320 degree plastic into....some/most silicones give off large amounts of formaldehyde gas when heated...causing the bubbles to form on the contact surface as seen in your photo's. This problem you show can also happen with the first few uses of the newly made mold, especially if your using molding silicone....it contains a small amount of release agent that will burn off with use. I used Alumilite High Strength 2 Silicone Mold and it is rated up to about 400 degrees. Do you think there could be any other mistakes that I am making? Thanks Quote Link to comment Share on other sites More sharing options...
camrynekai Posted March 30, 2015 Report Share Posted March 30, 2015 I used Alumilite High Strength 2 Silicone Mold and it is rated up to about 400 degrees. Do you think there could be any other mistakes that I am making? Thanks Sorry I have not used that brand. With the Lurecraft molding Silicone it really takes almost a week to 10 days before it has completely cured and leached out all of its release agents.....even after that it will take a few pours before it stops fizzing. I wouldn't sweat it...give a few more pours and see if your problem goes away which it should. Quote Link to comment Share on other sites More sharing options...
FatFace Fishing Lures Posted March 30, 2015 Author Report Share Posted March 30, 2015 Sorry I have not used that brand. With the Lurecraft molding Silicone it really takes almost a week to 10 days before it has completely cured and leached out all of its release agents.....even after that it will take a few pours before it stops fizzing. I wouldn't sweat it...give a few more pours and see if your problem goes away which it should. Ive been pouring with this brand of silicone for about 6 months now and ive always had this problem, which makes me believe that it is a pouring issue rather than a mold issue. Thank you for commenting. Quote Link to comment Share on other sites More sharing options...
kayaksticks Posted March 30, 2015 Report Share Posted March 30, 2015 does your melted plastic have bubbles in it before you pour? Quote Link to comment Share on other sites More sharing options...
FatFace Fishing Lures Posted March 30, 2015 Author Report Share Posted March 30, 2015 does your melted plastic have bubbles in it before you pour? No it does not, and the plastic that cools down in the pot dries without bubbles which makes me think that my mold is not letting the air escape. I just don't know how to get that air out. Quote Link to comment Share on other sites More sharing options...
Frank Posted March 30, 2015 Report Share Posted March 30, 2015 I know the easiest thing to blame is the plastic but one other thing that causes that type of bubbles(wavy surface) is bubbles in the silicone. You see when you pour the plastic in it heats the air within the mold and causes this. Do you know for sure the silicone has no bubbles? I know if you look in and see none there could be some just under the surface. It is really hard to get all the air out of silicone. Quote Link to comment Share on other sites More sharing options...
FatFace Fishing Lures Posted March 30, 2015 Author Report Share Posted March 30, 2015 I know the easiest thing to blame is the plastic but one other thing that causes that type of bubbles(wavy surface) is bubbles in the silicone. You see when you pour the plastic in it heats the air within the mold and causes this. Do you know for sure the silicone has no bubbles? I know if you look in and see none there could be some just under the surface. It is really hard to get all the air out of silicone. That makes a lot of sense. If there was bubbles in the silicone I would think that the bubbles would be consistent throughout all of my lures, but each lure has unique bubbles/dents. To test this further, I cooked some clear plastic so that I could see what was going on and what I saw was little air pockets on the inner walls of my mold. Do you think that it could still be a mold issue? Thank you. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted March 30, 2015 Report Share Posted March 30, 2015 Maybe spray the mold with PAM, or some other release agent. Quote Link to comment Share on other sites More sharing options...
Frank Posted March 31, 2015 Report Share Posted March 31, 2015 That makes a lot of sense. If there was bubbles in the silicone I would think that the bubbles would be consistent throughout all of my lures, but each lure has unique bubbles/dents. To test this further, I cooked some clear plastic so that I could see what was going on and what I saw was little air pockets on the inner walls of my mold. Do you think that it could still be a mold issue? Thank you. Yes it could be. Did you do anything to get rid of the bubbles before you made the mold? I used to vacumn the silicone them let it cure under pressure. This still did not work 100% but it was way better. Not being consistent could be from your plastic temp not being at the same temp all the time. It sound like a bit much but it halo out me with plastic and resin baits. Quote Link to comment Share on other sites More sharing options...
FatFace Fishing Lures Posted April 12, 2015 Author Report Share Posted April 12, 2015 Okay I figured it out, I don't get bubbles when my mold is pre-heated. I tried heating it up with a hair dryer and it got it up to about 150 degrees and poured my plastic at about 350 degrees and it was flawless. No bubbles at all. Thank you all for your input. Quote Link to comment Share on other sites More sharing options...
Basscandy92040 Posted April 13, 2015 Report Share Posted April 13, 2015 Okay I figured it out, I don't get bubbles when my mold is pre-heated. I tried heating it up with a hair dryer and it got it up to about 150 degrees and poured my plastic at about 350 degrees and it was flawless. No bubbles at all. Thank you all for your input. Was going to post what you just figured out. I have that problem if mold are cold also will happen when plastic is too cool... Quote Link to comment Share on other sites More sharing options...
