"Sticky" surface after Alumisol dip

[Fogeljazz]

Hi guys,

My friend and I are experimenting with coloring soft plastics. We tried an Alumisol dip with approx 30% softener to seal the coloring. The sealing worked but the surface of the bait became very sticky and tacky. It was so sticky that after we'd handled it for a while it wasn't shiny anymore. Does anyone know the reason for this sticky finish? Is this common when using a lot of softener in the Alumisol?

/Emil

[Mike - Alumilite]

Yes, you are exactly right. You are pushing the envelope of what the Alumisol can accept and you are basically feeling the excess softener in the system. 30% is pushing it. I'd try to cut it back 5-10% and see if it makes a difference. The more softener you use, the tackier it gets.

Mike

[Fogeljazz]

Ok, thanks Mike! We figured it was something along those lines. We'll just have to try a different mix of Alumisol and softener.
Do you know if Alumisol with 15-20% softener has a different density than "pure" Alumisol?
And does the viscosity differ a lot as well?

/Emil

[dahlberg]

Hi F
I use a 20% softener regularly, with no issues. Another possiblity is that it's under cooked. With the added softner, it's so thin it can be hard to tell when the material is at it's final state. I would try heating it for just a bit longer. And stir really well.
what I do when using really soft alumisol is dip a stick in it and let a few drops fall on my metal workbench. It cools quickly so I can check it for tackiness.
Often all it takes is a little more cooking and the tackiness is gone, but the material is super soft.
Beyond that, if you store them in a ziplock with a little vegetable or olive oil they won't feel tacky if they're over softened or under cooked!
One last thing, and please don't be insulted because it seems so obvious, but be sure you've totally stirred and shaken the goop that settles to the bottom of the Alumisol to insure it's all dissolved.
best
L

[Fogeljazz]

Thanks Larry, good points. We'll try cooking it a bit longer and do your "drop-test".
Could very well be a solution to our problem.

Of course I'm not insulted, it's very important to stir properly. And besides, it was my friend who did the testing last night, so I can always blame him if that was the problem

/Emil