The problem is that it doesn't totally evaporate, it leaves a RESIDUE and an oily one full of harmful chemicals at that. While the amount of finished product that one would smoke might seem so small that you couldn't see it being a problem, certain resionious chemicals can be very potent in extremely small amounts. Everyone in this room has first hand experience with that - it doesn't take much THC to get you high. It doesn't take much harmal resionous material left behind post evaporation to get into your bloodstream through your lungs, go to your brain, and cause damage. Tiny amounts go a long way in the brain.
Thus, if you have ANY questions regarding safety, play it safe. Smoke another day. We all do dumb things some times, but some people do dumb things that have long term consequences. NO ONE who does something dumb thinks, "I'm going to do something so stupid that it's gonna fuck up my brain". The people who end up screwed are the ones who use poor judgement and do things without thinking them through. In Bam's case, he came here because he was concerned about whether or not it's a dumb thing to do. Based on the opinions weighed in on this thread, if I had started it, I would flush my hash, cry, and have a hell of a story about this one time that I wasted some badass hash. Then, the next time I got my hands on some, I would be more careful about how I prepared it. It's REAL easy to be excited about getting something tough to come by - like hash - get all excited, and, in haste, prep it wrong. It's not so easy to toss it out when you know you might not be able to get more for months - or worse, if your buddies were counting on you to make them some badass hash.
Who knows all the stuff going on in the background here, and if Bam's buddies are waiting for the hash too, it never looks good to say, "oh yeah, uh, the hash was bad man." because they won't believe that. I'm just speculating.
Alchohol and even butane is not the same as paint thinner. There are different additives and special chemicals in paint thinner. Sure people huff it all the time, but does that mean it's safe? No. Sure people smoke/shoot/snort all kinds of shit and it doesn't instantly fuck their brains up. Does that mean it's safe and healthy and you should too?
Will it kill you to smoke the paint thinner hash? Probably not. Will it fuck you up for life? maybe not. Maybe it depends on how much you smoke. Maybe you could smoke a fraction of a gram of it and be fine, maybe not. Maybe you would have to smoke quite a bit over a long period of time. Maybe you should cut your hash with Asbestos because you read somewhere that will increase it's potency 100%. That's allot of maybes.
How much paint thinner hash will it take to fry your brain? Only way to find out is to fry your brain. Do you want to go exploring those limits? It's your brain... I put enough value on mine to say be conservative with it.