Oops! Clear cast issues. What do you think caused this?

[ramaroodle]

I finally got my technique down for label casting and had a few successful test batches so I did a 12 tube batch last night and they looked like this in the morning. I used Alumilite (Clear, not slow). In the pot overnight at 50 PSI. The other test batches I did came out great with some generic brand resin.

 

[JohnU]

You might have gotten it under pressure too late. Working time can go by quickly when first starting out having to mix, pour, secure tank lid and pressurize tank. If you warmed your resin prior to mixing it might have gotten too warm shortening your working time. If you didn't warm side B it might have used up more working time than you expected to get it mixed properly.

 

[jttheclockman]

John mentioned what I was going to suggest. I never used that stuff but I do know even with Silmar41 you have to be quick to get in pot. Epoxy resins you have more time.

 

[ramaroodle]

You might have gotten it under pressure too late. Working time can go by quickly when first starting out having to mix, pour, secure tank lid and pressurize tank. If you warmed your resin prior to mixing it might have gotten too warm shortening your working time. If you didn't warm side B it might have used up more working time than you expected to get it mixed properly.

John mentioned what I was going to suggest. I never used that stuff but I do know even with Silmar41 you have to be quick to get in pot. Epoxy resins you have more time.

That's what I figured, but just checking with the experts! While I was pouring them I said to myself, "Self, you better pick up the pace and have a sense of urgency!". Probably didn't help that it wasn't Alum. Slow. Only a few minutes after I put them in the pot I looked at what was left in the cup and it was rock hard! I had my radiant ceiling heater on so I'm pretty sure the resin was close to 80 degrees. Operator error.

Thanks guys. Just making sure it wasn't something else.

 

[JohnU]

Just a tip… I like to warm side B up to 90°-100° but I never warm soda A. This way the thicker side of the two is thinner and mixes quicker. I never warm side A. I mix with an electric drill and a 1" spade bit ( with the tip and sharp points ground off ). This way I can get the resin mixed in about 1 minute and pour 24 to 28 vertical blanks at a time with Alumilite Clear. You would be ok to use Clear Slow to get your process down. Especially since you do t have to wait to pour clear resin since you're not worried about keeping color separation. I like to mix both side A and B in a kitchen spouted mixing container with a handle so I can pour easier. Plus, once the resin is cited in the mixing bow, it peels out to be clean and ready for reuse. Good luck and feel free to reach out with any questions.

 

[ramaroodle]

Just a tip… I like to warm side B up to 90°-100° but I never warm soda A. This way the thicker side of the two is thinner and mixes quicker. I never warm side A. I mix with an electric drill and a 1" spade bit ( with the tip and sharp points ground off ). This way I can get the resin mixed in about 1 minute and pour 24 to 28 vertical blanks at a time with Alumilite Clear. You would be ok to use Clear Slow to get your process down. Especially since you do t have to wait to pour clear resin since you're not worried about keeping color separation. I like to mix both side A and B in a kitchen spouted mixing container with a handle so I can pour easier. Plus, once the resin is cited in the mixing bow, it peels out to be clean and ready for reuse. Good luck and feel free to reach out with any questions.

I'm going from bad to worse but I'm thinking this is water showing up somewhere, maybe in the bottom of the mixing cup. (It was close to 3am) but I did get them in the pot a lot quicker. So, I'm not bothered by the cloudiness. "operator error" and easy to fix.

I did copy your spade bit mixer idea. The spouted kitchen cup is a great idea. I was thinking about a funnel but that takes 2 hands and is an invitation to "sloppage". I will heat up the B side. It's coming down to my technique so I'm a happy camper. I've got jigs built so the process is down to about 5 mins from printer to finished wrapped blank. That in itself was a 2 week learning curve.

 

[JohnU]

While I warm side B I also warm the blanks in the pressure pot. This burns off humidity and warms the labels so resin sticks better. I use a shop clamp light and position it above the opening of the tank shining down with a 60-100 watt bulb. Just make sure your not using LED bulbs. They dont produce any heat.

The cloudiness is usually from either under mixed resin or not even amounts of A and B. Moisture usually foams up and doesn't cure but if it's a trace amount it could be like that. Keep at it, you'll get it!

 

[ramaroodle]

While I warm side B I also warm the blanks in the pressure pot. This burns off humidity and warms the labels so resin sticks better. I use a shop clamp light and position it above the opening of the tank shining down with a 60-100 watt bulb. Just make sure your not using LED bulbs. They dont produce any heat.

The cloudiness is usually from either under mixed resin or not even amounts of A and B. Moisture usually foams up and doesn't cure but if it's a trace amount it could be like that. Keep at it, you'll get it!

Thanks. I've done a fair amount of blank casting over the years which is why I'm not worried about the cloudiness. I'll make sure I cover all of the contingencies tonight.

 

[ramaroodle]

Just out of curiosity, why don't people use some of the UV-resistant clear-cast epoxy products that don't require pressure??

 

[jttheclockman]

Just out of curiosity, why don't people use some of the UV-resistant clear-cast epoxy products that don't require pressure??

They are not casting resins. They are bartop resins