Small fine bubbles

[bzptlx]

OK, just jumped into the dep end. Doing some label casting and have my first experiment. I am using the Underhill Vertical Casting system but am showing what appears to be some shiny spots on the surface of the label. I think they are bubbles. I am using the waterproof matte label from OnLine Labels and alumilite clear slow. I am using a converted HF pot at 45PSI. Any ideas?

 

[Todd in PA]

Might try hitting the tubes for 60 seconds with a hair dryer to vaporize any moisture before right before your pour. I'm doing that with most of my casts now.

 

[pssherman]

I think the shiny patches are places where the resin didn't bond properly to the label. I would heat the label/mold to 125F and heat part B of the resin to 90 - 100F before mixing. I also heat the tank continuosly while pressurized. Temperature of the mold and resin seems to be key to getting a good bond.

 

[bzptlx]

Thanks for the replies. I am going to heat the mold/label with a hair dryer and wait a little longer to pour so the resin is about 95 - 100 degrees. Then I am going to leave in pot a little longer. Once more into the fold......

 

[bzptlx]

Tgese came out clear but the edge of the label where it overlaps curls slightly. I burnished them but tgey still curled. Can I put a micro line of thin CA on them prior to casting?

 

[arkie]

Tgese came out clear but the edge of the label where it overlaps curls slightly. I burnished them but tgey still curled. Can I put a micro line of thin CA on them prior to casting?

Yes, but examine the glue line closely after casting. The refraction index of the CA differs from that of PR resin. The result is that any raised portion of CA under the resin looks like a bit of glass or a bubble. I can't speak to your resin, except to advise you to check closely.

I can add that you may be overheating the label adhesive with the hair dryer, causing the edge to curl.

 

[its_virgil]

CA and Alumilite Clear and Clear Slow do not play well together.