I lit a match and blew it out at each pipe joint and found that the smoke was promptly sucked int the pipe through the joints especially where the pipe is put together at the seam leaving at least a 1/16 space. So heres the million dollar question. How much draft would i gain by sealing these joints as in is it worth my while? There is 4 joints. Englander nc13. No OAK (yet). thanx all.