casting advice - yellow and blue makes green

[hooked]

I am a beginner when it comes to casting. I have mostly been doing clear label casting and it has been going well. I have done a few other hybrid blanks and have had no real issues with mixing colors Currently, I am trying to make a couple dozen simple blue and gold/yellow pen blanks for my son's school. I am having a real hard time not getting a visible green tone when gently swirling the yellow/gold into the blue. I am hoping there may be some suggestions to cut down on this effect.

I am using alumilite clear slow. I am using alumilite dyes and powders. I am mixing my blue (dye) resin and pouring it into my mold. When the blue hits 95 with my infrared thermometer I am adding the yellow/gold (dye and mica). In my latest attempt, I let it sit until 97 before I added yellow and there was no difference. As soon as I pour yellow I see the edges turning green, gently swirl I see the green appear more. When I put them under pressure and remove they look more teal. Is there anything I can do differently to achieve this? different pigment? Let the resin get warmer? It took over 15 minutes to get to 97 so I was concerned about waiting any longer. Is 97 still too low for mixing these colors? Is clear slow not the best alumilite resin for this project?

I can easily get some acrylic acetate or buy the below blanks from Zac which are exactly what I am trying to achieve but would really like to be able to make the blanks for this project.

Thanks for any advice.

 

[NJturner]

I am a beginner when it comes to casting. I have mostly been doing clear label casting and it has been going well. I have done a few other hybrid blanks and have had no real issues with mixing colors Currently, I am trying to make a couple dozen simple blue and gold/yellow pen blanks for my son's school. I am having a real hard time not getting a visible green tone when gently swirling the yellow/gold into the blue. I am hoping there may be some suggestions to cut down on this effect.

I am using alumilite clear slow. I am using alumilite dyes and powders. I am mixing my blue (dye) resin and pouring it into my mold. When the blue hits 95 with my infrared thermometer I am adding the yellow/gold (dye and mica). In my latest attempt, I let it sit until 97 before I added yellow and there was no difference. As soon as I pour yellow I see the edges turning green, gently swirl I see the green appear more. When I put them under pressure and remove they look more teal. Is there anything I can do differently to achieve this? different pigment? Let the resin get warmer? It took over 15 minutes to get to 97 so I was concerned about waiting any longer. Is 97 still too low for mixing these colors? Is clear slow not the best alumilite resin for this project?

I can easily get some acrylic acetate or buy the below blanks from Zac which are exactly what I am trying to achieve but would really like to be able to make the blanks for this project.

Thanks for any advice.

View attachment 320024

I am really surprised by one of your comments, which to me points to your problem. Alumilite Slow should be at a much higher temp after 15 minutes - by then it should be well over 100. The colors will always blend before the Alumilite starts to set up (begins to gel) so if its too cool, you get the problem you are seeing. I would recheck your measuring of both the A and B - it MUST be by weight, not volume. 'A' should be exactly the same weight as the 'B', missing that will cause the slow cure time and can affect the strength of the casting. You cannot measure by volume and get good results. Also, not sure what the air temperature or the temp your pre-mix bottles are before working, but I would try to be somewhere in a normal comfort range versus really cool. I also wait until my mixed solutions are approaching 110 or so before blending when I need real separation between colors - just be sure to have your pressure pot ready to go so you can quickly put the mix under pressure.

 

[JohnU]

NJturner hit the mail on the head. Let your resin reach 110-115 before pouring. That will help keep color separation. The less you stir or manually swirl the better. That's where you make new colors. Try pouring a layer of blue, then drizzle a little yellow here and there, then blue, then yellow, etc. this will allow the resin to swirl itself with gravity, as one layer covers parts of the other. Then if you want to move a wire through it after your done, move it slowly and don't over do it. Good luck!

 

[hooked]

Thank you for the advice! I do weigh out my resin and am very careful about it. I pour in my basement shop which is at 65 right now. I also store my resin in that room, in the dark. My resin is about 7-8 months old, but just opened the seal, so I am not sure if that is affecting it.

I will wait for the temperature to rise to 110-115 on my next attempt. My concern was the 12 minute working time and needing to wait much longer for the temperature to get up there. Maybe I will try warming my molds and slightly warming the resin before mixing.

 

[target64]

The 12 minute working time should only be considered as a baseline. Your particular working conditions dictate actual time. I never mix colors below 115 degrees. Good luck and have fun

 

[Brian G]

I appreciate the question and the answers given. I've struggled with colors blending too much when casting with Alumilite. I followed the 95° advice I've read and was a little panicky when I got too much higher than that. Now that I know 110-115 is within reason, I'll give that a go.