Merlin Posted October 11, 2014 Posted October 11, 2014 Grandmaster has made a suggestion concerning phenolic resin and hexamine for hardening crossettes/comets. Can anyone provide a formula concerning solvents and amounts of phenolic resin and hexamine. The resin is in a solid form so I suppose it should be milled or ground to powder. What percentages of hex/phenolic should be used with what solvent to ram crossetttes?
dagabu Posted October 11, 2014 Posted October 11, 2014 I'll add what I know, 6% phenolic resin as a substitute for the red gum, dextrin, sgrs or other binders except for Parlon, PVC, or any chlorine donor, they all stay. To make the resin syrup, grind up your resin to a fine powder (very easy to do, I did 10# in five minutes through a garbage disposal) and make a 1:1 mix of denatured alcohol to resin. Put in a sealed container and shake for a while, let set, shake, repeat. It takes me about 30 minutes to get it all dissolved. To the syrup add 8% of the resin weight (100g resin add 8g of hexamine) and shake that into the mix as well. To use in comets: Make your dry comp as you normally would, add 200% of the needed resin/hex to the comp as a syrup, knead well, screen, add additional denatured as needed but keep relatively dry. Pump with enough pressure to see some liquid around the pump base, eject, place in a drying box at no less than 140° overnight to allow the curing to take place. Example Comp: Potassium Nitrate 584 Charcoal (airfloat) 117 Sulfur 78 Phenolic Resin 60 Hexamine 8 Metal Particles 153
dagabu Posted October 11, 2014 Posted October 11, 2014 There is a PUBLIC youtube video of a W39J comet here:
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