P17 is some bad ass stuff. Yes high heat. I believe its rated to something like 450deg. Its a structural plastic when cured so it will have strength without being bonded to a surface unlike regular body filler. Its a solid plastic when its cured much like straight fiberglass resin or epoxy. Its been around for 20+ years. Its big in the marine and aerospace industry. Doesnt shrink and cures hard. It is much harder to sand than regular bodyfiller so its not something you really want to use as your main filler to skim and flatten panels unless you like sanding. Super sticky and bonds to just about everything.
Bad ass for sure! I'm just now checking this stuff out and found the TDS on it. Its over half the Tensile Strength of a good weld, and also has flex strength, so it should be good for factory seams.
@Jim C Do you see a way to make this thin/liquid enough to pore into a mold?
https://www.expresscomposites.com/pub/media/wysiwyg/TDS-AD/TDS_-_P-17.pdf
TYPICAL PHYSICAL PROPERTIES Tensile Strength (ASTM D-638.91)..................................4074psi (28MPa)
Tensile Elongation (ASTM D-638.91.................................................................................................1.2%
Flexural Strength (ASTM D-790.92)...................................................................................................7080psi (49MPa)
Compressive Strength (ASTM D-695.91) ........................................................................................8992psi (62MPa)
Shrinkage (Cast Bar)(ASTM D-2566.86)............................................................................................0.00982 in/in
Coefficient of Linear Thermal Expansion (TMA) (ppm/°F (°C)) ...............................................25 (46)
Water Absorption after 24 hours immersion in distilled water (ASTM D-570)..................0.149%
NOTE: All high heat resistant systems typically exhibit a slight color change at the extreme end of the
elevated temperature range when used in tooling repairs
It didn't seem too expensive for what it is
https://www.expresscomposites.com/ad17