Resin and temperature

[Performance nut]

Anyone have any idea at what temperature resin cast parts start to have problems? I'm seeing conflicting information. I'm certain it varies by manufacturer but I'm sure there is a rule of thumb of "Do not exceed XXX temperature". Any feedback is appreciated

 

[Steve Shannon]

Anyone have any idea at what temperature resin cast parts start to have problems? I'm seeing conflicting information. I'm certain it varies by manufacturer but I'm sure there is a rule of thumb of "Do not exceed XXX temperature". Any feedback is appreciated

What type of resin? Phenolic resins have a high temperature resistance (428°F) and then decompose. Epoxy resins have a lower temperature threshold.

 

[Performance nut]

What type of resin? Phenolic resins have a high temperature resistance (428°F) and then decompose. Epoxy resins have a lower temperature threshold.

I didn't cast these so I'm not sure. Is there a way to tell by looking at them? How low are the epoxy resin thresholds from phenolic?

 

[Steve Shannon]

I didn't cast these so I'm not sure. Is there a way to tell by looking at them? How low are the epoxy resin thresholds from phenolic?

Epoxy resins begin degrading at about 350°F. Obviously, different epoxies have different temperatures where they degrade.
Resins are generally thermosetting. As such they don’t melt, but if exposed to too high temperatures they start to decompose and lose strength.
There are other resins as well, including polyester resins. Wikipedia has pretty decent articles about them.
I think I can tell the difference by heating or filing a piece and smelling it. You might also be able to compare color and density. Of course if amendments have been added that no longer holds.
So, scratch and sniff, color, and source.