[Steve]

I’ve been using Casting Craft polyester resin for over 5 years to great success. BUT, occasionally I have color separation. Let me explain.
I make custom made pens, usually in two colors. My mold is 5″L X 3″W X 3/4″T(depth) I use a digital scale to measure 2/3 and 1/3 of the mold volume. ~ 4.5 and 2.5 ounces respectively. 5 drops of catalyst per ounce of resin. As I said I’ve done this many times. The 1/3 portion, which I call the secondary color, gets extra drops of catalyst (15-16 @ 2.5 oz.) so it “flashes” faster than the primary color. That creates a syrupy pour into the looser/more liquid primary color and does not mix together. In other words: red primary + yellow secondary will not turn orange after a light stir/swirl motion but instead leave streaks of yellow throughout the red.. Of course some does mix together. I’m not looking for virgin color division.
My issue is the colors layering. The secondary color occasionally floats to the top.There IS a bit dispersed in the primary. I have timed it to about 7 minutes before it starts to become a blob instead of thickerer. I use Jacquard powered pigments. Every thing is new-ish, temperatures are normal,things are relatively clean, well as clean as poring resins can get lol.
And it is not just a certain pigment that does it. I’ve had it happen with every color and as I said it happens occasionally. Maybe once in ~30 pours. It is an interesting result but not quite what I’m looking for. I use it anyways and if I don’t like the look , well I try again.
Any ideas on the layering issue?

[Katherine Swift]

Hi Steve,

So that I’m clear, the second color you mix, which has extra catalyst added, turns into a blob and floats to the top instead of remaining intermixed with the first color you mix.

Do I have that right?

[Steve]

No. I first mix both colors into their respective separate containers, like Solo cups, weigh them and add 5 drops/ oz
for the primary (2/3 volume) then remix it for a minute. Pour into the mold
I then add the requisite 5/oz. to the second color plus a few extra drops. remix for a minute , then hand stir, checking viscosity, for about 7 min. It varies. Once it is ALMOST a blob lol , there is a fine line there, I pour a stream around and around on top of the primary. A stir stick to swirl gently.Pull the primary up through.
Ever see how they make creamer designs on a coffee? Kinda like that but throughout.
IF it becomes a blob, still pliable, two sticks to stretch it out, chop it up etc. In that instance you have virtually no mixing of colors. It is a “red and yellow” pour.
What I am encountering is the second color floating to the top. After the gentle swirling. It is not a definitive separation like oil and water but a marked one none the less I am about to turn the offending pour and I’ll add it to the FILCKR page. Not sure if that link is posted here.

[Steve]

EDIT
Ok they are uploaded here:
https://www.flickr.com/photos/turduil/
There are 4 pictures, NOT very good ones but there are 3 of the layered blank and pen (green and red), one of a correct swirled pen (red/silver). There are other examples of 2 color pens on the page that are done right.

So my question still remains: What causes the one color to ” float” to the top?

[Steve]

EDIT#2
Five new pictures of a new pour to illustrate what I do.
Weighing and drop amounts marked on cups
Pouring primary color in the mold, GOLD
After about 7 min pouring the second color,BLUE, onto primary. It had thickened up.
Swirling colors together.It is a little more mixed than I like but I was trying to do it and take pictures.
Sorry about the pic quality but it shows the process.

[Katherine Swift]

Hi Steve,

My best guess here is that the second color, with extra catalyst added compared to the first color, is heating up quicker and trying to cure faster than the first color. Why it’s floating, I don’t know. Weird!

Are you using Castin’ Craft colors with this resin?

[Steve]

I use Jacquard powdered pigments. I don’t know much about liquids physics but I would think that the thicker color would settle instead of float. I’ve used CC colors also, the opaque liquid ones and again, occasionally, had the separation. I like the Alumilite you have here on the site, never used them but I’ll order some soon I think.

I’m not sure if you looked at the page I linked but the results were not terrible, just not what I strive for. Of note: the RED/BLUE pen is an example of the “blob” effect where the blue had set and I was able to kinda slice it up a little.

I’ll be turning a blank from EDIT#2 (5 new pics) today and will post a pic of that too. Hopefully a much better one.

There are pen turning forums also that I can query. Your site came up with a google search so I figured I’d ask here. I’m sure I’m not the only one this has ever happened to. It is a mystery to me though too.

[Steve]

EDIT #3

There are 3 new pics to show how the documented pour process looks when turned. Not a bad result. It really is a crap shoot how any one pour will come out. At least this one was mixed. I get 3 blanks per mold and the other two will look totally different. That is the cool part, it is always a surprise.

If I find any reasonable explanation on another site, for the color floating, I’ll post it here.

Thank you for your time.

Steve.

[Katherine Swift]

Thanks Steve. I am curious as to how and why this is happening.

[Steve]

I didn’t want you to think I forgot about you…. Noone on the other pen forums could give me a clue.I just got a different resin, Silmar 41, and it happened again!! It HAS to be that particular color that just won’t mix. Luckily I caught it while it was still pliable and chopped it up into the primary color. It’ll be an interesting look, I hope, when turned. Thank you for your time on this.

[Author]

Posts