I'm going to go out on a limb and assume you are purging on parchment paper or an oil slick pad inside vac. chamber. Try this. Release vacuum. Remove parchment paper with concentrate on it. Let ot cool to rm. temp. You want to ball the concentrate up in the center. Technique: Grab any corner of paper and fold toward center letting oil stick to itself, and quickly in one motion, pull corner away leaving oil in center. Do this from all sides until you have your concentrate in a nice ball in the center of your parchment paper. Place back in center of vac. chamber. Now, at room temp. start vac pump. It should start to expand (depending on how much butane you already purged) into a "muffin". Looks light and almost foam like. If you can reach full vac without "muffin" touching sides of chamber keep a full -29in. Hg. If gets too big release vac. a bit and repeat until you have a full vac. (-29.5 in. Hg) Now hopefully you have some kind of double boiler set-up, with heat element. (I assume you do) You said you were running around 100 F. Thats cool bcuz the terps. should be intact. Raise heat to 120 degrees F. Oil surface temp. Not element temp. Not water temp. The temp of the actual concentrate itself. For this I use an infrared thermometer. Cheap online if you don't have one. If that's what you were already doing cool. If not buy one! Now, for this batch, use whatever analog thermometer you may have. Should start waxing up after an hour or two. If it flattens back out b4 it waxes up, repeat the balling up back into the center process. Try not to let go past 125 F. Just for terpenes sake. It is done when it no longer reacts, and is of your desired consistency. Good luck brother. Hope I can help. Let me know how it turned out....peace!