APMM Community Forum : Casting
Welcome Guest   
 Subject : Tints for Clear Casting Urethanes.. 08/22/2018 12:29:58 PM 
Posts: 99
Location: Overland Park, KS
(Thread moved from MILE, original question by Matt Williquette)

I’m running some of BJB’s clear TC-879 resin and we need to tint the resin red. However, we need to maintain transparency.
Thus far we’ve always used BJB’s 6800 series pigments, but as you probably know they are intended for opaque and not translucent parts.

I’ve been in touch with Specialty Coatings & Chemicals as I believe this is what I’ve used many years ago. However, I’m looking for additional alternate options.
Does anyone have tints the use that can put a deep color into clear urethane without affecting the transparency?

 Subject : Re:Tints for Clear Casting Urethanes.. 08/22/2018 12:31:26 PM 
Posts: 99
Location: Overland Park, KS
We've had good results tinting clear urethane and keeping transparency using the Smooth On "So Strong" dyes.

They have worked well with several resin types even including some SLA printing resins.

Have not tried it with any BJB resins, though....

Nick Dothage
 Subject : Re:Tints for Clear Casting Urethanes.. 08/22/2018 12:33:37 PM 
Posts: 99
Location: Overland Park, KS

We have some of that, but are getting similar results to the BJB tints.
The attached photo shows the red on top that I need and the part on bottom is the closest we’ve been able to get with the BJB stuff.

Matt Williquette

 Subject : Re:Tints for Clear Casting Urethanes.. 08/22/2018 12:36:14 PM 
Posts: 99
Location: Overland Park, KS
I have good success with Reynolds Crystal Clear series, which is a water clear series. Selection is based on wall thickness, except for the 220, which requires heat curing, but adds the benefit of higher heat deflection.


Reynolds has both tints and pigments. Mostly often I work with the So-Strong Tints to keep the clarity.

The material is a little fussy-- but manageable, and the casting can polish up beautifully. It is not compatiable with every silicon mold—I typically pressure cast into a tin-cure mold that has been carefully cured to draw out the alcohol, washed and dried. On multiple castings, I find a sweet spot in how long to cure the casting inside the mold to optimize surface quality—again, based on wall thickness. For polished surfaces, I do not use a mold release.

Alternatively, their 320 color-match series is less expensive and less fussy, but adds just a bit of yellow cast, as the A side runs yellow. It is not as clear. With deep tinting this may not be an issue. The materials are less fussy in handling and less expensive.

Attached is a reproduction signal lens for an vintage scooter. Mold was pulled from an original, cast in Crystal Clear with red tint. Wall thickess varies from 1 to 2mm. Could definitely achieve a deeper tint if necessary.

Jill Kenik

# of Topics per Page