Oddly enough, I just had a friend send me a few RRD47 and RRD50 to test out. I have had a few that I went as high as a CD18 in and couldn't get a good pool or full pool with-they just burned oddly. I put RRD50 in one and it started smoking after about 15 minutes-not bad just puffs-put it out and put in the 47. I got a great pool, excellent throw-but one thing, after about 5 hours my melt pool decreased quite abit and I noticed a little soot on the rim of the jar-that could have been from the 50 and I didn't notice at that time. Not quite sure if the 47 was too hot or not hot enough---it was out to the edge after 2 hours but not real deep yet and was looking really good close to the 3 hour-I didn't check it much until 5 when I noticed the melt pool very shallow. I am going to burn it again tonight and see-there was quite a bit of hang up from the previous wick and the 47 took care of it so thinking that may have something to do with it. Thanks-the timing was awesome!!!!!!! Tracey