SharkWhisperer Posted July 17, 2020 Posted July 17, 2020 (edited) Yes, there's literally thousands of "phenolic resins" that can be created. The PR I bought from a known vendor "should" be acetone soluble, but I question that and vendor provides limited info on composition with packaging--I haven't reached out directly yet. Most PRs in pyro are soluble in both alcohol(s) or acetone/MEK, no? My PR doesn't seem to want to dissolve in acetone, which seems really odd. What's your experience with PR solvents? Edited July 17, 2020 by SharkWhisperer
Arthur Posted July 17, 2020 Posted July 17, 2020 I did once try and fail to make a comet using parlon (chlorinated rubber) and acetone, It didn't dry in full NV sun in the 8 hours I left it. I have heard that some USA acetone solvent is an acetone solution in water, but can't prove that.
Blackmach Posted July 17, 2020 Posted July 17, 2020 my phenolic resin is perfectly soluble in alcohol and acetone. to check it put on the finger a little phenolic and wet with acetone, if your fingers become sticky it is soluble.
SharkWhisperer Posted July 17, 2020 Author Posted July 17, 2020 I did once try and fail to make a comet using parlon (chlorinated rubber) and acetone, It didn't dry in full NV sun in the 8 hours I left it. I have heard that some USA acetone solvent is an acetone solution in water, but can't prove that.I've never had an issue with parlon not dissolving in acetone. 8 hours in the NV sunshine, wow. My rubber stars are primed and ready to fly within hours in a shady breeze. Drying box or porch when it's cold. Acetone readily absorbs atmospheric water--some add drying agents to larger containers. And you need to be careful if using dollar store fingernail polish remover/acetone--check the labels--some say 100% acetone and have been fully functional for me. Others have a slew of additional girly ingredients that might hinder burn characteristics. The MSDS should be available for any acetone sold as a solvent, and would indicate relative % of acetone and other potential additives. But 100% is usually closer to 99.5%, with the half percent balance likely water. Because acetone doesn't form azetropes like water does with some alcohols, the water and acetone are easily separated by distillation, but who's gonna do that for a cheap solvent? Some add molecular sieves, which can in theory reduce water so your acetone is 99.9% pure. But sheesh, if it's water contamination, then your acetone had quite a large water fraction to need such extended drying, unless your stars were 4-inch comets, tsk tsk. Like PRs, there are a lot of parlons available. If it's a brand new parlon batch, then the parlon's also a suspect. If the exact same parlon's performed fine in the past, with the same overall comp formulation, then it's probably your solvent causing headaches.
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