^ I have black tar only here in California and I never heated it. It can take up to 20 minutes to dissolve in cold water. Just leave it there and check back on it. If you're in a hurry then you can mix it to make it break down faster.
Heroin is soluble in water though and by heating it you can make all the cut that's normally insoluble break down and become soluble. So you end up injecting that stuff whereas if you inject cold that stuff won't go through the filter.
OP, just because you register doesn't mean the needle can't slip out. I think you're not holding your hand steady enough. Also, sometimes you're just barely in the vein so you'll register but the tiniest movement and you slip out but there's no way to tell. What I would do was inject 1/3 of the shot, re-register, inject 1/3, re-register, inject the last 1/3. It's a hassle, but trust me, it's worth it. Also, make sure you get ever last bit out of the syringe before pulling it out. If you pull out in a hurry the needle can still be dripping a little when you take it out of your vein and through the skin before it touches air and that can burn.
And I agree with Swimmingdancer, some stuff just burns. But 80% of the time it's user error.
the OP asked if it needed to be heated. But just because a lot of people do something doesn't make it necessary. Whether tar heroin requires heat has been a very discussed issue on Bluelight and the consensus seems to be that it shouldn't require heat, that heat just causes crap other than the heroin to dissolve. When you don't heat it, it doesn't all dissolve so people assume they are not getting all the heroin, but in reality only the actual heroin needs to dissolve and heroin is plenty soluble in room temp water. And you should be filtering it properly of course. I don't have a lot of personal experience with BTH myself, so I can't guarantee that BTH never needs heat, but I am just going by what most of the "experts" on the board have said (see this thread for example). I probably should have said "to my knowledge it shouldn't need heat" or something to that effect. Personally, although many disagree with this, I don't think that whether or not you apply heat is a huge issue, because most of the most commonly used cuts are relatively non-toxic and heat can kill some bacteria and viruses (definitely not all though!), so if you really feel you need to heat it that's up to you. But I don't think that not heating BTH, if you're filtering it properly, should be causing the issues that the OP is experiencing.
