Wetting pearlex before mixing in PR

[Gary Beasley]

I've noticed when I put dry pearlex powder into resin to mix I get a fine foam from the air trapped in the powder. Is there anything I can use to wet the powder as I mix it to force the air out? I tried some denatured alcohol on a small batch but I'm not sure the stuff is going to set up.

 

[Gary Beasley]

Okay, I just went downstairs to look at it, a full hour after I mixed it and it's just now starting to set. I'm thinking use just enough to barely wet the pearlex, not float it and I'll get better results.
I'll know tomorrow what kind of disaster that blank is.

 

[PTsideshow]

The fine powder has lots of surface area to trap air when it is mixed in larger amounts. You can try adding it in a little at a time while stirring. It will take longer. Since it is a basically mica powder and pigments like carbon black, iron oxides etc.

You can try taking some of the resin a small aount of the total batch and then mix in all the powder so it is wetted you could use a hand vacuum pump to remove the air from the color mix before mixing it in with the rest of the resin.

There are some powder paints that are a real pain in the A$$ to mix.
The addition of other solvents will just through off the resin mix.
:clown:

 

[PenMan1]

I thin the resin to a "water consistency" with heat and ultra sound when using PearlEx mica pearls. This seems to eliminate the foaming. Additionally, using the Coastal Scents powders seems to eliminate many of the bubble problems. It may be my imigination (because the CS micas are about 60 percent less expensive than PearlEx) but I think CS mixes with PR with far fewer problems.

For me, additional solvents just makes my resin casting MORE COMPLICATED and adds more variables to an already "inexact science".

Respectfully submitted.

 

[Ed McDonnell]

Styrene is used to thin PR. You might consider that to wet your pearlex instead of alcohol. Take appropriate precautions when working with styrene.

Ed

 

[Dai Sensei]

I add my Pearlex type powders to the PR and mix in with a icy-pole/ice-cream stick. I then heat the resin and most of the bubbles seam to go. Only then do I add the catalyst, mixing carefully to avoid causing bubbles, but I also pour on a vibrating table (bandsaw table whilst running) that also helps remove any bubbles.

 

[PTsideshow]

I think CS mixes with PR with far fewer problems.

For me, additional solvents just makes my resin casting MORE COMPLICATED and adds more variables to an already "inexact science".

Respectfully submitted.

The biggest difference in the products is the PearlEx products are a formula of coloring pigments and a rock product mica(isinglass) shinny sheet like material with high heat properties and electrically non conductive. Is used to hold heating elements in curling irons, toasters etc.

Sheet Mica, used in electronics

The Coastal Scents and other cosmetic coloring and additives are a formula of Mylar squares of assorted sizes (to give different effects) The planes of reflection of the light hitting it. And assorted color producing pigments, which result in a product that is INERT and can be used in products that come in contact with humans. Whether they be make up, medicine, or shampoo and bath products. The shampoo's with the shimmering look are using the silver material.

The important word is INERT it has no other materials with it, that can react with the resins. The Mica can have trace elements/minerals with it.

And like Andy said adding random solvents to the resins will only add additional problems.
:clown:

 

[NewLondon88]

just so you know, adding styrene as a thinner wouldn't be a
'random solvent' .. it would be the one that is already in the resin.
It works fine. I didn't notice it affecting curing time, although I
don't really pay attention to that anyway.

 

[PTsideshow]

just so you know, adding styrene as a thinner wouldn't be a
'random solvent' .. it would be the one that is already in the resin.
It works fine. I didn't notice it affecting curing time, although I
don't really pay attention to that anyway.

Was referring to the op's

I tried some denatured alcohol on a small batch

It seems that a lot of people trying casting just will add what they have handy whether it is a color/dye, filler or as a solvent to achieve some kind of results. Mostly not good!

In reading the the casting forum on this site, nobody can say that the people that do some outstanding casting of blanks don't share the correct info, or help with tips etc.

Yet people will tend to cheap out, when trying to cast stuff. No matter how many times it has been posted things don't work! The tutorials have been great, the library is full of info.

I did casting back in the dark ages of the late 60's,70's and 80's. I can say that things have improved greatly since then. But the thing that haven't changed is the simple fact that. What doesn't work, doesn't work, no matter how many times you try it and expect (hope) you have different out come.
:clown:

 

[Gary Beasley]

Now where do you go about getting the styrene?

 

[Ed McDonnell]

Your PR supplier should have it. If not, you can get it here:

Solvents

For your purposes, a pint would go a long way.

Ed

 

[Jim Burr]

I've had great results with;
1) mixing my remaining Pearl-ex with the correct CS mica powder.
2) mixing powder and resin...mixing the crap out of it with a popcicle stick in a drill.
3) vibrating the crap outa that to get rid of the bubbles
4) mix catalyst and stir again...vibrate...pour one color in mold.
5) wait for gel, mix and keep vibrating.