Talk Composites - The Forum for Advanced Composites

Mixing Colored Glas Cast resins

http://www.talkcomposites.com/Topic25849.aspx

By ni9eofse7en - 4/25/2018 10:44:54 AM

Morning,

I intend to mix different coloured batches of Glass Cast together for pen blanks etc. In the past mixed colours I created using poly resins have blended together and muddied the result, so here's my question, how long would you leave coloured resins before mixing to get a good colour separation but a one piece cast, is it a time calculation, a temperature of the resin calculation or a mix of both, assuming room temperature between 20 and 30 degrees Celsius?

I appreciate getting to a B state would give defined lines, but I want to swirl and get a random mix of colours.

Second, if I wanted thin ribbons of resin, how long again to be in a usable state to fold and create a wave like pattern in a cast piece?

Thanks in advance

John
By ni9eofse7en - 4/25/2018 4:36:03 PM

 
Warren (Staff) - 4/25/2018 4:23:43 PM
Hi John,

Whilst I don't have a definitive answer for you as there are variables with different colourants which can affect results and we would always recommend a small test piece.  The problem is there are quite a few variables that effect the cure times, and more specifically in your case, the time for the resin to begin to thicken.  There is standard data for pot life, gel times and curing times measured using a set volume.  However the specifics of what you need to know is in essence, how the viscosity changes as it cures.  The change in viscosity will determine how much the resin colours bleed and how much you can move and hence mingle them together.  Unfortunately there is no specific data for that kind of stage in the cure process.

Factors that are going to influence this are volume of mixed resin,  temperature, the profile of the resin volume - eg spread thin or in one block in a pot. etc etc.  As a result, realistically , you would need to experiment to find what works for you.  You could be looking at as soon as an hour, or up to several hours, so initially you will need to keep a close eye on things.

To get the artistic effect. pour the colours in a swirl but then resist mixing or moving the mould afterwards as the colours will bleed somewhat without any help
Don't add any additional heat into the resin as this encourages mixing and bleeding. Then you could check it every now and then until you are happy and then start the artistic work of blending and manipulating the resin to get the desired effect.  Remember you can work in 3D and cast in layers with different effects at different layers.

In answer to your other query without seeing the project I envisage that you would need to cast onto a non-stick flexible surface and wait until the B-stage then manipulate the resin into the shape required wearing gloves. Then the waves would need supporting until fully cured otherwise they will try to go back to the flat shape again.

I've inserted an image of a project using GlassCast 10 and blue and white powder art pigments so you can see the colours - we did apply heat to encourage lacing and cell development but it gives a bit of context when I helped to mix them together.




Thanks Warren, I was expecting some experimentation, but thought I would try and pick your brains first. I got my order last week, so just waiting for a rise in outside temp before trying the Glass Cast.