Please don't use isopropyl. Even if it does say 90%, it really isn't worth it to mess with that stuff. It isn't food-grade ethanol and who knows what residues it could leave behind. Not to mention it comes in a non-food-grade cheap plastic bottle, probably from China. While cheap liquor is occasionally sold in plastic bottles, they use a special plastic to minimize the leeching of toxins into the liquor that is going to be ingested. Because isopropyl isn't intended to be ingested, the plastic bottles it is sold in are probably cheap and the isopropyl probably pulls in a lot of toxins. Just spend the extra five or ten dollars and buy a bottle of Everclear or some type of 180 proof vodka. Using isopropyl is an awfully big risk to take over a few measly dollars. You can't put a price on your health and peace of mind anyway. :thumbsup:

The easiest way to make a concentrate using ethanol is: http://boards.cannabis.com/concentra...-combined.html

Just make green dragon and then allow all the alcohol to evaporate. Then scrape what is left behind on the glass and you will have a thick sticky oil that you can smoke, vape, or cook with. :thumbsup: