Yes you can make BHO from it, and it's amazing.
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As soon as i saw the title of this thread i went to youtube and got that link haha! Normally when you run BHO with buds or trim you get around a 10-20 percent return on average. But when you run keif you can actually get around a 50% return, which is really nice. So if you put in 14 grams of kief into a blaster, you'll get around 7 grams of oil. There is a few things you have to do though cause when running kief you risk a higher chance of a blowout. This is due to the kief being so fine and compressing together from the pressure coming out of the butane can.
So
Step 1 in preventing this is too make sure you throw in a few tiny buds(that are the size of a dime or so) thru out the extractor to allow proper airflow, Mainly by the tip where you're blasting in the butane. This basically acts as perlite does too soil. Allows proper airflow and prevents major compacting.
And
Step 2 is
NEVER UNPRESSURIZE THE BUTANE TIL YOUR DONE WITH THAT RUN. Don't start blasting the butane thru the kief and decide you need to regrip the extractor and stop spraying for a second. This will pretty much guarantee that you will have a blow out and ruin your kief and oil. The tip where you are spraying the butane into will shoot out of your hands like a rocket, taking the butane bottle with it. So get a really good grip on that extractor and spray til you've ran the desired amount of butane thru it.